Minor Histocompatibility Antigens
Minor Histocompatibility Loci
Histocompatibility Antigens
H-Y Antigen
HLA-B40 Antigen
HLA Antigens
T-Lymphocytes, Cytotoxic
Graft vs Host Disease
Histocompatibility, Maternal-Fetal
Major Histocompatibility Complex
Histocompatibility
Graft vs Leukemia Effect
Histocompatibility Antigens Class I
Transplantation, Homologous
Histocompatibility Antigens Class II
HLA-A Antigens
HLA-B7 Antigen
Graft vs Tumor Effect
HLA-A1 Antigen
Transplantation Immunology
T-Lymphocytes
Histocompatibility Testing
Skin Transplantation
Cytotoxicity, Immunologic
Bone Marrow Transplantation
Isoantigens
Receptors, Purinergic P2X5
HLA-B38 Antigen
Mice, Inbred Strains
HLA-A2 Antigen
Isoantibodies
Hematopoietic Stem Cell Transplantation
Cytotoxicity Tests, Immunologic
Antigens, Neoplasm
Mice, Inbred C57BL
CD8-Positive T-Lymphocytes
Graft Rejection
Mice, Inbred BALB C
Antigen Presentation
Receptors, Antigen, T-Cell
Clone Cells
Immunodominant Epitopes
Epitopes, T-Lymphocyte
Immune Tolerance
Radiation Chimera
Mice, Inbred C3H
Leukemia
Lymphocyte Culture Test, Mixed
Amino Acid Sequence
Antigens, Surface
Lymphocyte Activation
CD4-Positive T-Lymphocytes
Molecular Sequence Data
Lymphocyte Transfusion
Immunotherapy, Adoptive
Tissue Donors
HLA-DR Antigens
B-Lymphocytes
HLA-B Antigens
Immunotherapy
Graft vs Host Reaction
Flow Cytometry
Genes, MHC Class II
Alleles
Peptides
Base Sequence
Interferon-gamma
HLA-D Antigens
Receptors, Antigen, T-Cell, alpha-beta
beta 2-Microglobulin
Graft Survival
Immunogenetics
Histocompatibility Antigen H-2D
Cells, Cultured
Beta-Globulins
Leukemia, Myelogenous, Chronic, BCR-ABL Positive
Leukemia, Myeloid
Genes, MHC Class I
Antigen-Presenting Cells
Antigens, CD8
T-Lymphocyte Subsets
Hematologic Neoplasms
Polymorphism, Genetic
Mice, Inbred CBA
Lymphocytes
Graft Enhancement, Immunologic
Dendritic Cells
Corneal Transplantation
Polymorphism, Single Nucleotide
Antigen-Antibody Reactions
HLA-C Antigens
Antigens, CD
Cutting edge: alloimmune responses against major and minor histocompatibility antigens: distinct division kinetics and requirement for CD28 costimulation. (1/253)
Comparative study of alloimmune responses against major and minor histocompatibility Ags has been limited by the lack of suitable assays. Here, we use a bioassay that permits tracking of alloreactive CD4+ T cell populations as they proliferate in response to major or minor histocompatibility Ags in vivo. Division of alloreactive CD4+ T cells proceeded more rapidly in response to major histocompatibility Ags than minor Ags, although CD4+ T cells alloreactive to minor Ags had a similar capacity to divide successively up to eight times after stimulation. Allorecognition of minor histocompatibility Ags was highly dependent on CD28 costimulation, with the frequency of CD4+ T cells proliferating in response to minor Ags in the absence of CD28 costimulation reduced up to 20-fold. These findings highlight differences in signaling processes that lead to allorecognition of major and minor histocompatibility Ags and have implications on the design of interventions aimed at abrogating these responses. (+info)Feasibility of immunotherapy of relapsed leukemia with ex vivo-generated cytotoxic T lymphocytes specific for hematopoietic system-restricted minor histocompatibility antigens. (2/253)
Allogeneic bone marrow transplantation (BMT) is a common treatment of hematologic malignancies. Recurrence of the underlying malignancy is a major cause of treatment failure. Donor-derived cytotoxic T lymphocytes (CTLs) specific for patients' minor histocompatibility antigens (mHags) play an important role in both graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) reactivities. mHags HA-1 and HA-2 induce HLA-A*0201-restricted CTLs in vivo and are exclusively expressed on hematopoietic cells, including leukemic cells and leukemic precursors, but not on fibroblasts, keratinocytes, or liver cells. The chemical nature of the mHags HA-1 and HA-2 is known. We investigated the feasibility of ex vivo generation of mHag HA-1- and HA-2-specific CTLs from unprimed mHag HA-1- and/or HA-2-negative healthy blood donors. HA-1 and HA-2 synthetic peptide-pulsed dendritic cells (DCs) were used as antigen-presenting cells (APC) to stimulate autologous unprimed CD8(+) T cells. The ex vivo-generated HA-1- and HA-2-specific CTLs efficiently lyse leukemic cells derived from acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL) patients. No lytic reactivity was detected against nonhematopoietic cells. Sufficient numbers of the CTLs can be obtained for the adoptive immunotherapy purposes. In conclusion, we present a feasible, novel therapy for the treatment for relapsed leukemia after BMT with a low risk of GVHD. (+info)Biochemical and immunogenetic analysis of an immunodominant peptide (B6dom1) encoded by the classical H7 minor histocompatibility locus. (3/253)
Of the many minor histocompatibility (H) Ags that have been detected in mice, the ability to induce graft vs host disease (GVHD) after bone marrow transplantation is restricted to a limited number of immunodominant Ags. One such murine Ag, B6dom1, is presented by the H2-Db MHC class I molecule. We present biochemical evidence that the natural B6dom1 peptide is indistinguishable from AAPDNRETF, and we show that this peptide can be isolated from a wide array of tissues, with highest levels from the lymphoid organs and lung. Moreover, we employ a novel, somatic cell selection technique involving CTL-mediated immunoselection coupled with classical genetics, to show that B6dom1 is encoded by the H7 minor H locus originally discovered approximately 40 years ago. These studies provide a molecular genetic framework for understanding B6dom1, and exemplify the fact that mouse minor H loci that encode immunodominant CTL epitopes can correspond to classical H loci originally identified by their ability to confer strong resistance to tumor transplantation. Additionally, these studies demonstrate the utility of somatic cell selection approaches toward resolving H Ag immunogenetics. (+info)CD8+ cytotoxic T cell repertoire implicated in grafts-versus-leukemia effect in a murine bone marrow transplantation model. (4/253)
In our model of murine BMT, the lethal GVHD which develops against DBA/2 host incompatible minor histocompatibility antigens (mHAgs) can be prevented by donor preimmunization before grafting. Recipient mice become long survivors (LS mice) and tolerant to host mHAgs. However, a GVL effect is preserved and mediated by CD8+ CTL able to kill P815 tumor cells in vitro and in vivo. To explain why a GVL exists without GVHD, we compared the CTL activity of LS and B10.D2 donor mice after immunization with DBA/2 spleen cells or with P815 cells. Experimental results indicated that: (1) the level of cytotoxicity for H-2b incompatible cells was similar in LS and B10.D2 mice; (2) CTL recognizing host DBA/2 mHAgs, whose expression is restricted to the spleen or is shared between spleen and P815 cells, were partially unresponsive in LS mice; (3) P815 injection into LS mice predominantly generated CTL specific for antigens restricted to P815 cells, the repertoire of which was not tolerized. Characterization of TCR beta chain showed that the diversity of Vbeta and Jbeta usage by CD8+ T cells activated after P815 injection is considerably restricted in LS mice, compared to B10.D2 donor mice. These results indicated that the GVL effect in LS mice involved mainly T cells specific for tissue-restricted antigens expressed on P815 cells and not on normal DBA/2 spleen cells. In addition, the absence of GVHD may be attributed to the unresponsiveness of CD8+ CTL specific for host mHAgs expressed on DBA/2 spleen cells. (+info)Polyriboinosinic polyribocytidylic acid (poly(I:C)) induces stable maturation of functionally active human dendritic cells. (5/253)
For vaccination strategies and adoptive immunotherapy purposes, immature dendritic cells (DC) can be generated from adherent monocytes using GM-CSF and IL-4. Presently, the only clinically applicable method to induce stable maturation of DC is the use of supernatants of activated monocytes (monocyte-conditioned medium (MCM)). MCM contains an undefined mixture of cytokines and is difficult to standardize. Here we report that stable maturation of DC can be simply induced by the addition of polyriboinosinic polyribocytidylic acid (poly(I:C)), a synthetic dsRNA clinically applied as an immunomodulator. Poly(I:C)-treated DC show a mature phenotype with high expression levels of HLA-DR, CD86, and the DC maturation marker CD83. This mature phenotype is retained for 48 h after cytokine withdrawal. In contrast to untreated DC, poly(I:C)-treated DC down-regulate pinocytosis, produce high levels of IL-12 and low levels of IL-10, induce strong T cell proliferation in a primary allo MLR, and effectively present peptide Ags to HLA class I-restricted CTL. In conclusion, we present a simple methodology for the preparation of clinically applicable mature DC. (+info)Prevention of graft versus host disease by inactivation of host antigen-presenting cells. (6/253)
Graft versus host disease, an alloimmune attack on host tissues mounted by donor T cells, is the most important toxicity of allogeneic bone marrow transplantation. The mechanism by which allogeneic T cells are initially stimulated is unknown. In a murine allogeneic bone marrow transplantation model it was found that, despite the presence of numerous donor antigen-presenting cells, only host-derived antigen-presenting cells initiated graft versus host disease. Thus, strategies for preventing graft versus host disease could be developed that are based on inactivating host antigen-presenting cells. Such strategies could expand the safety and application of allogeneic bone marrow transplantation in treatment of common genetic and neoplastic diseases. (+info)CD8(+) minor histocompatibility antigen-specific cytotoxic T lymphocyte clones eliminate human acute myeloid leukemia stem cells. (7/253)
Effective immunotherapy for human leukemia based on infusions of T lymphocytes requires the identification of effector T cells that target the leukemic stem cell. The transplantation of human acute myeloid leukemia into nonobese diabetic/severe combined immune deficient (SCID) mice has identified a rare leukemic progenitor termed the SCID leukemia-initiating cell, which is present in low frequency in the leukemic population and is essential for establishing leukemic hematopoiesis. Thus, this transplant model may be ideally suited to identify effector T cells with antileukemic activity. We report that CD8(+) cytotoxic T lymphocyte (CTL) clones specific for minor histocompatibility antigens inhibit the engraftment of human acute myeloid leukemia cells in nonobese diabetic/SCID mice and demonstrate that this inhibition is mediated by direct CTL recognition of SCID leukemia-initiating cells. These results indicate that CD8(+) minor histocompatibility antigen-specific CTL may be mediators of the graft-versus-leukemia effect associated with allogeneic hematopoietic cell transplantation and provide an experimental model to identify and select T cell clones for immunotherapy to prevent or treat relapse after allogeneic hematopoietic cell transplantation. (+info)Nitric oxide mediation of active immunosuppression associated with graft-versus-host reaction. (8/253)
In the immunosuppression accompanying the lethal systemic graft-versus-host reaction (GVHR) directed against minor histocompatibility antigens in irradiated adult mice, we previously determined that non-T, non-B, L-leucine methyl ester (LME)-sensitive cells were implicated via two different mechanisms: one, which is interferon-gamma (IFN-gamma)-dependent and affects both T-cell proliferative responses and thymus-independent antibody production by CD5(+) B cells; and a second, which is IFN-gamma-independent and affects B-cell proliferative responses. Because IFN-gamma induces the production of nitric oxide (NO), a potent immunosuppressive molecule, we investigated the involvement of NO in the suppression mediated by the LME-sensitive cells. Inducible NO synthase (iNOS) mRNA, iNOS protein, and the stable end products of iNOS pathway, L-citrulline and nitrite, were detected early in GVHR in LME-sensitive spleen cells taken ex vivo and could be amplified in vitro by T and B mitogens. Inhibition of NO production with arginine analogs (aminoguanidine, N(G)-monomethyl-L-arginine [LMMA]), like anti-IFN-gamma antibodies, reversed suppression of both T-cell responses to concanavalin A and CD5(+) B-cell responses, but not of B-cell response to lipopolysaccharides (LPS). The GVHR-associated, IFN-gamma-dependent immunosuppression of T-cell proliferation and of antibody synthesis by CD5(+) B cells is the consequence of NO production by LME-sensitive cells. Immunohistochemical analyses indicate that these cells belong to the macrophage lineage. (+info)Minor histocompatibility antigens (miHA) are proteins that exist in cells which can stimulate an immune response, particularly in the context of transplantation. Unlike major histocompatibility complex (MHC) antigens, which are highly polymorphic and well-known to trigger strong immune responses, miHA are generally less variable and may not be as immediately apparent to the immune system.
Minor histocompatibility antigens can arise from differences in genetic sequences that code for proteins outside of the MHC region. These differences can result in the production of altered or unique peptides that can be presented on the surface of cells via MHC molecules, where they may be recognized as foreign by the immune system.
In the context of transplantation, the recipient's immune system may recognize and attack donor tissues expressing these miHA, leading to graft rejection or graft-versus-host disease (GVHD). This is particularly relevant in hematopoietic stem cell transplantation (HSCT), where the transferred stem cells can differentiate into various cell types, including immune cells that may recognize and attack the recipient's tissues.
Understanding miHA and their role in transplant rejection has led to the development of strategies to minimize graft rejection and GVHD, such as T-cell depletion or targeted therapies against specific miHA.
Minor histocompatibility loci (MHL) refer to the genetic regions, excluding the major histocompatibility complex (MHC), that contain genes encoding antigens capable of inducing an immune response. These antigens are present in various tissues and cells of the body and can be recognized as foreign by the immune system. In the context of transplantation, MHL mismatches between a donor and recipient can lead to graft rejection or graft-versus-host disease (GVHD) even when MHC matching has been achieved.
MHL antigens are typically peptides derived from proteins that result from polymorphisms in the genes encoding them. These peptides are presented on the cell surface by MHC molecules, allowing T cells to recognize and respond to them. Since there are many more minor histocompatibility loci than major histocompatibility loci, finding a donor who is fully matched at both MHL and MHC levels is extremely challenging.
In summary, minor histocompatibility loci are genetic regions outside the major histocompatibility complex that contain genes encoding antigens capable of inducing an immune response. These antigens can contribute to transplant rejection or GVHD in cases where there is a mismatch between donor and recipient.
Histocompatibility antigens, also known as human leukocyte antigens (HLAs), are proteins found on the surface of most cells in the body. They play a critical role in the immune system's ability to differentiate between "self" and "non-self" cells. Histocompatibility antigens are encoded by a group of genes called the major histocompatibility complex (MHC).
There are two main types of histocompatibility antigens: class I and class II. Class I antigens are found on almost all nucleated cells, while class II antigens are primarily expressed on immune cells such as B cells, macrophages, and dendritic cells. These antigens present pieces of proteins (peptides) from both inside and outside the cell to T-cells, a type of white blood cell that plays a central role in the immune response.
When foreign peptides are presented to T-cells by histocompatibility antigens, it triggers an immune response aimed at eliminating the threat. This is why histocompatibility antigens are so important in organ transplantation - if the donor's and recipient's antigens do not match closely enough, the recipient's immune system may recognize the transplanted organ as foreign and attack it.
Understanding the role of histocompatibility antigens has been crucial in developing techniques for matching donors and recipients in organ transplantation, as well as in diagnosing and treating various autoimmune diseases and cancers.
The H-Y antigen is a complex of historically significant, male-specific proteins that are encoded by genes on the Y chromosome. These antigens were first discovered through studies of tissue rejection in animal models and were later found to be important in the field of transplantation immunology.
In a medical definition, the H-Y antigen refers to a group of antigens that are expressed on the cell surface of nucleated cells in males, including those found in tissues such as skin, muscle, and blood cells. They are recognized by the immune system as foreign when transplanted into females, leading to a rejection response.
The H-Y antigen has been the subject of extensive research due to its role in sex determination and differentiation, as well as its potential implications for autoimmune diseases and cancer biology. However, it's worth noting that the clinical relevance of the H-Y antigen is limited, and its study is primarily of academic interest.
The HLA-B40 antigen is a human leukocyte antigen (HLA) serotype that is part of the major histocompatibility complex (MHC) class I molecules. These molecules are found on the surface of most nucleated cells and play a crucial role in the immune system by presenting peptides to T-cells.
The HLA-B40 antigen specifically refers to a group of related HLA-B alleles that share a common epitope, which is a specific region of the molecule that can be recognized by antibodies. The HLA-B40 antigen includes several different HLA-B alleles, such as HLA-B*40:01, HLA-B*40:02, and HLA-B*40:06, among others.
The HLA-B40 antigen has been associated with susceptibility to certain diseases, including some forms of cancer and autoimmune disorders. However, the specific role of this antigen in disease susceptibility is not fully understood and is an area of ongoing research.
HLA (Human Leukocyte Antigen) antigens are a group of proteins found on the surface of cells in our body. They play a crucial role in the immune system's ability to differentiate between "self" and "non-self." HLA antigens are encoded by a group of genes located on chromosome 6, known as the major histocompatibility complex (MHC).
There are three types of HLA antigens: HLA class I, HLA class II, and HLA class III. HLA class I antigens are found on the surface of almost all cells in the body and help the immune system recognize and destroy virus-infected or cancerous cells. They consist of three components: HLA-A, HLA-B, and HLA-C.
HLA class II antigens are primarily found on the surface of immune cells, such as macrophages, B cells, and dendritic cells. They assist in the presentation of foreign particles (like bacteria and viruses) to CD4+ T cells, which then activate other parts of the immune system. HLA class II antigens include HLA-DP, HLA-DQ, and HLA-DR.
HLA class III antigens consist of various molecules involved in immune responses, such as cytokines and complement components. They are not directly related to antigen presentation.
The genetic diversity of HLA antigens is extensive, with thousands of variations or alleles. This diversity allows for a better ability to recognize and respond to a wide range of pathogens. However, this variation can also lead to compatibility issues in organ transplantation, as the recipient's immune system may recognize the donor's HLA antigens as foreign and attack the transplanted organ.
Cytotoxic T-lymphocytes, also known as CD8+ T cells, are a type of white blood cell that plays a central role in the cell-mediated immune system. They are responsible for identifying and destroying virus-infected cells and cancer cells. When a cytotoxic T-lymphocyte recognizes a specific antigen presented on the surface of an infected or malignant cell, it becomes activated and releases toxic substances such as perforins and granzymes, which can create pores in the target cell's membrane and induce apoptosis (programmed cell death). This process helps to eliminate the infected or malignant cells and prevent the spread of infection or cancer.
Graft-versus-host disease (GVHD) is a condition that can occur after an allogeneic hematopoietic stem cell transplantation (HSCT), where the donated immune cells (graft) recognize the recipient's tissues (host) as foreign and attack them. This results in inflammation and damage to various organs, particularly the skin, gastrointestinal tract, and liver.
Acute GVHD typically occurs within 100 days of transplantation and is characterized by symptoms such as rash, diarrhea, and liver dysfunction. Chronic GVHD, on the other hand, can occur after 100 days or even years post-transplant and may present with a wider range of symptoms, including dry eyes and mouth, skin changes, lung involvement, and issues with mobility and flexibility in joints.
GVHD is a significant complication following allogeneic HSCT and can have a substantial impact on the patient's quality of life and overall prognosis. Preventative measures, such as immunosuppressive therapy, are often taken to reduce the risk of GVHD, but its management remains a challenge in transplant medicine.
Histocompatibility, maternal-fetal, refers to the compatibility between the human leukocyte antigens (HLAs) and other antigenic proteins expressed on the fetal tissues and those present in the mother's immune system. The HLAs are a group of proteins encoded by the major histocompatibility complex (MHC) and play a crucial role in the recognition and presentation of foreign peptides to the immune cells.
During pregnancy, the fetal tissues express paternal HLA antigens that can be recognized as non-self by the mother's immune system. However, the maternal-fetal interface, which includes the placenta and decidua, has several mechanisms to prevent the activation of the maternal immune response against the fetus. These mechanisms include the expression of unique HLA molecules (HLA-G, -C, and -E) by the trophoblast cells, which have immunomodulatory functions, as well as the production of anti-inflammatory cytokines and the suppression of pro-inflammatory responses.
Despite these immune tolerance mechanisms, in some cases, the maternal immune system may still recognize the fetal tissues as foreign and mount an immune response, leading to pregnancy complications such as preeclampsia, recurrent miscarriage, or intrauterine growth restriction. The degree of histocompatibility between the mother and fetus can influence the risk of these complications, with a higher degree of mismatch increasing the risk.
In transplantation medicine, the concept of histocompatibility is critical in matching donors and recipients to minimize the risk of rejection. However, in pregnancy, the unique immune environment at the maternal-fetal interface allows for the coexistence of two genetically distinct individuals without the need for full histocompatibility.
The Major Histocompatibility Complex (MHC) is a group of cell surface proteins in vertebrates that play a central role in the adaptive immune system. They are responsible for presenting peptide antigens to T-cells, which helps the immune system distinguish between self and non-self. The MHC is divided into two classes:
1. MHC Class I: These proteins present endogenous (intracellular) peptides to CD8+ T-cells (cytotoxic T-cells). The MHC class I molecule consists of a heavy chain and a light chain, together with an antigenic peptide.
2. MHC Class II: These proteins present exogenous (extracellular) peptides to CD4+ T-cells (helper T-cells). The MHC class II molecule is composed of two heavy chains and two light chains, together with an antigenic peptide.
MHC genes are highly polymorphic, meaning there are many different alleles within a population. This diversity allows for better recognition and presentation of various pathogens, leading to a more robust immune response. The term "histocompatibility" refers to the compatibility between donor and recipient MHC molecules in tissue transplantation. Incompatible MHC molecules can lead to rejection of the transplanted tissue due to an activated immune response against the foreign MHC antigens.
Histocompatibility is the compatibility between tissues or organs from different individuals in terms of their histological (tissue) structure and antigenic properties. The term is most often used in the context of transplantation, where it refers to the degree of match between the human leukocyte antigens (HLAs) and other proteins on the surface of donor and recipient cells.
A high level of histocompatibility reduces the risk of rejection of a transplanted organ or tissue by the recipient's immune system, as their immune cells are less likely to recognize the donated tissue as foreign and mount an attack against it. Conversely, a low level of histocompatibility increases the likelihood of rejection, as the recipient's immune system recognizes the donated tissue as foreign and attacks it.
Histocompatibility testing is therefore an essential part of organ and tissue transplantation, as it helps to identify the best possible match between donor and recipient and reduces the risk of rejection.
The "Graft versus Leukemia (GvL) Effect" is a term used in the field of hematopoietic stem cell transplantation to describe a desirable outcome where the donor's immune cells (graft) recognize and attack the recipient's leukemia cells (host). This effect occurs when the donor's T-lymphocytes, natural killer cells, and other immune cells become activated against the recipient's malignant cells.
The GvL effect is often observed in patients who have undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT), where the donor and recipient are not genetically identical. The genetic disparity between the donor and recipient creates an environment that allows for the recognition of host leukemia cells as foreign, triggering an immune response against them.
While the GvL effect can be beneficial in eliminating residual leukemia cells, it can also lead to complications such as graft-versus-host disease (GvHD), where the donor's immune cells attack the recipient's healthy tissues. Balancing the GvL effect and minimizing GvHD remains a significant challenge in allo-HSCT.
H-2 antigens are a group of cell surface proteins found in mice that play a critical role in the immune system. They are similar to the human leukocyte antigen (HLA) complex in humans and are involved in the presentation of peptide antigens to T cells, which is a crucial step in the adaptive immune response.
The H-2 antigens are encoded by a cluster of genes located on chromosome 17 in mice. They are highly polymorphic, meaning that there are many different variations of these proteins circulating in the population. This genetic diversity allows for a wide range of potential peptide antigens to be presented to T cells, thereby enhancing the ability of the immune system to recognize and respond to a variety of pathogens.
The H-2 antigens are divided into two classes based on their function and structure. Class I H-2 antigens are found on almost all nucleated cells and consist of a heavy chain, a light chain, and a peptide fragment. They present endogenous peptides, such as those derived from viruses that infect the cell, to CD8+ T cells.
Class II H-2 antigens, on the other hand, are found primarily on professional antigen-presenting cells, such as dendritic cells and macrophages. They consist of an alpha chain and a beta chain and present exogenous peptides, such as those derived from bacteria that have been engulfed by the cell, to CD4+ T cells.
Overall, H-2 antigens are essential components of the mouse immune system, allowing for the recognition and elimination of pathogens and infected cells.
Histocompatibility antigens, class I are proteins found on the surface of most cells in the body. They play a critical role in the immune system's ability to differentiate between "self" and "non-self." These antigens are composed of three polypeptides - two heavy chains and one light chain - and are encoded by genes in the major histocompatibility complex (MHC) on chromosome 6 in humans.
Class I MHC molecules present peptide fragments from inside the cell to CD8+ T cells, also known as cytotoxic T cells. This presentation allows the immune system to detect and destroy cells that have been infected by viruses or other intracellular pathogens, or that have become cancerous.
There are three main types of class I MHC molecules in humans: HLA-A, HLA-B, and HLA-C. The term "HLA" stands for human leukocyte antigen, which reflects the original identification of these proteins on white blood cells (leukocytes). The genes encoding these molecules are highly polymorphic, meaning there are many different variants in the population, and matching HLA types is essential for successful organ transplantation to minimize the risk of rejection.
Homologous transplantation is a type of transplant surgery where organs or tissues are transferred between two genetically non-identical individuals of the same species. The term "homologous" refers to the similarity in structure and function of the donated organ or tissue to the recipient's own organ or tissue.
For example, a heart transplant from one human to another is an example of homologous transplantation because both organs are hearts and perform the same function. Similarly, a liver transplant, kidney transplant, lung transplant, and other types of organ transplants between individuals of the same species are also considered homologous transplantations.
Homologous transplantation is in contrast to heterologous or xenogeneic transplantation, where organs or tissues are transferred from one species to another, such as a pig heart transplanted into a human. Homologous transplantation is more commonly performed than heterologous transplantation due to the increased risk of rejection and other complications associated with xenogeneic transplants.
Histocompatibility antigens Class II are a group of cell surface proteins that play a crucial role in the immune system's response to foreign substances. They are expressed on the surface of various cells, including immune cells such as B lymphocytes, macrophages, dendritic cells, and activated T lymphocytes.
Class II histocompatibility antigens are encoded by the major histocompatibility complex (MHC) class II genes, which are located on chromosome 6 in humans. These antigens are composed of two non-covalently associated polypeptide chains, an alpha (α) and a beta (β) chain, which form a heterodimer. There are three main types of Class II histocompatibility antigens, known as HLA-DP, HLA-DQ, and HLA-DR.
Class II histocompatibility antigens present peptide antigens to CD4+ T helper cells, which then activate other immune cells, such as B cells and macrophages, to mount an immune response against the presented antigen. Because of their role in initiating an immune response, Class II histocompatibility antigens are important in transplantation medicine, where mismatches between donor and recipient can lead to rejection of the transplanted organ or tissue.
HLA-A antigens are a type of human leukocyte antigen (HLA) found on the surface of cells in our body. They are proteins that play an important role in the immune system by helping the body recognize and distinguish its own cells from foreign substances such as viruses, bacteria, and transplanted organs.
The HLA-A antigens are part of the major histocompatibility complex (MHC) class I molecules, which present peptide fragments from inside the cell to CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs). The CTLs then recognize and destroy any cells that display foreign or abnormal peptides on their HLA-A antigens.
Each person has a unique set of HLA-A antigens, which are inherited from their parents. These antigens can vary widely between individuals, making it important to match HLA types in organ transplantation to reduce the risk of rejection. Additionally, certain HLA-A antigens have been associated with increased susceptibility or resistance to various diseases, including autoimmune disorders and infectious diseases.
HLA-B7 antigen is a type of human leukocyte antigen (HLA) found on the surface of cells in our body. The HLAs are proteins that help our immune system recognize and fight off foreign substances, such as viruses and bacteria. Specifically, HLA-B7 is a class I HLA antigen, which presents peptides from inside the cell to CD8+ T cells, a type of white blood cell that plays a crucial role in the immune response.
HLA-B7 has been identified as one of the many different HLA types that can be inherited from our parents. It is located on chromosome 6 and has several subtypes. The HLA-B7 antigen is associated with certain diseases, such as ankylosing spondylitis, a type of arthritis that affects the spine. However, having this HLA type does not necessarily mean that a person will develop the disease, as other genetic and environmental factors are also involved.
It's important to note that HLA typing is used in organ transplantation to match donors and recipients and reduce the risk of rejection. Knowing a patient's HLA type can help identify compatible donors and improve the chances of a successful transplant.
The "Graft vs Tumor Effect" is a term used in the field of transplantation medicine, particularly in allogeneic hematopoietic stem cell transplantation (HSCT). It refers to the anti-tumor activity exhibited by donor immune cells (graft) against residual malignant cells (tumor) in the recipient's body.
After HSCT, the donor's immune system is reconstituted in the recipient's body. If the donor and recipient are not identical, there may be differences in their major and minor histocompatibility antigens, which can lead to a graft-versus-host disease (GVHD) where the donor's immune cells attack the recipient's tissues. However, these same donor immune cells can also recognize and target any residual tumor cells in the recipient's body, leading to a graft vs tumor effect.
This effect can contribute to the elimination of residual malignant cells and reduce the risk of relapse, particularly in hematological malignancies such as leukemia and lymphoma. However, it is important to balance this effect with the risk of GVHD, which can cause significant morbidity and mortality. Therefore, strategies such as donor selection, graft manipulation, and immunosuppressive therapy are used to optimize the graft vs tumor effect while minimizing GVHD.
HLA-A1 antigen is a type of human leukocyte antigen (HLA) class I molecule that plays an important role in the immune system. The HLAs are proteins found on the surface of cells that help the immune system distinguish between the body's own cells and foreign substances, such as viruses and bacteria.
The HLA-A1 antigen is one of several different types of HLA-A molecules, and it is determined by a specific set of genes located on chromosome 6. The HLA-A1 antigen is expressed on the surface of some cells in the human body and can be detected through laboratory testing.
The HLA-A1 antigen is associated with certain diseases or conditions, such as an increased risk of developing certain types of cancer or autoimmune disorders. It is also used as a marker for tissue typing in organ transplantation to help match donors and recipients and reduce the risk of rejection.
It's important to note that the presence or absence of HLA-A1 antigen alone does not determine whether someone will develop a particular disease or experience a successful organ transplant. Other genetic and environmental factors also play a role in these outcomes.
Transplantation Immunology is a branch of medicine that deals with the immune responses occurring between a transplanted organ or tissue and the recipient's body. It involves understanding and managing the immune system's reaction to foreign tissue, which can lead to rejection of the transplanted organ. This field also studies the use of immunosuppressive drugs to prevent rejection and the potential risks and side effects associated with their use. The main goal of transplantation immunology is to find ways to promote the acceptance of transplanted tissue while minimizing the risk of infection and other complications.
T-lymphocytes, also known as T-cells, are a type of white blood cell that plays a key role in the adaptive immune system's response to infection. They are produced in the bone marrow and mature in the thymus gland. There are several different types of T-cells, including CD4+ helper T-cells, CD8+ cytotoxic T-cells, and regulatory T-cells (Tregs).
CD4+ helper T-cells assist in activating other immune cells, such as B-lymphocytes and macrophages. They also produce cytokines, which are signaling molecules that help coordinate the immune response. CD8+ cytotoxic T-cells directly kill infected cells by releasing toxic substances. Regulatory T-cells help maintain immune tolerance and prevent autoimmune diseases by suppressing the activity of other immune cells.
T-lymphocytes are important in the immune response to viral infections, cancer, and other diseases. Dysfunction or depletion of T-cells can lead to immunodeficiency and increased susceptibility to infections. On the other hand, an overactive T-cell response can contribute to autoimmune diseases and chronic inflammation.
Histocompatibility testing, also known as tissue typing, is a medical procedure that determines the compatibility of tissues between two individuals, usually a potential donor and a recipient for organ or bone marrow transplantation. The test identifies specific antigens, called human leukocyte antigens (HLAs), found on the surface of most cells in the body. These antigens help the immune system distinguish between "self" and "non-self" cells.
The goal of histocompatibility testing is to find a donor whose HLA markers closely match those of the recipient, reducing the risk of rejection of the transplanted organ or tissue. The test involves taking blood samples from both the donor and the recipient and analyzing them for the presence of specific HLA antigens using various laboratory techniques such as molecular typing or serological testing.
A high degree of histocompatibility between the donor and recipient is crucial to ensure the success of the transplantation procedure, minimize complications, and improve long-term outcomes.
Skin transplantation, also known as skin grafting, is a surgical procedure that involves the removal of healthy skin from one part of the body (donor site) and its transfer to another site (recipient site) that has been damaged or lost due to various reasons such as burns, injuries, infections, or diseases. The transplanted skin can help in healing wounds, restoring functionality, and improving the cosmetic appearance of the affected area. There are different types of skin grafts, including split-thickness grafts, full-thickness grafts, and composite grafts, which vary in the depth and size of the skin removed and transplanted. The success of skin transplantation depends on various factors, including the size and location of the wound, the patient's overall health, and the availability of suitable donor sites.
Immunologic cytotoxicity refers to the damage or destruction of cells that occurs as a result of an immune response. This process involves the activation of immune cells, such as cytotoxic T cells and natural killer (NK) cells, which release toxic substances, such as perforins and granzymes, that can kill target cells.
In addition, antibodies produced by B cells can also contribute to immunologic cytotoxicity by binding to antigens on the surface of target cells and triggering complement-mediated lysis or antibody-dependent cellular cytotoxicity (ADCC) by activating immune effector cells.
Immunologic cytotoxicity plays an important role in the body's defense against viral infections, cancer cells, and other foreign substances. However, it can also contribute to tissue damage and autoimmune diseases if the immune system mistakenly targets healthy cells or tissues.
Bone marrow transplantation (BMT) is a medical procedure in which damaged or destroyed bone marrow is replaced with healthy bone marrow from a donor. Bone marrow is the spongy tissue inside bones that produces blood cells. The main types of BMT are autologous, allogeneic, and umbilical cord blood transplantation.
In autologous BMT, the patient's own bone marrow is used for the transplant. This type of BMT is often used in patients with lymphoma or multiple myeloma who have undergone high-dose chemotherapy or radiation therapy to destroy their cancerous bone marrow.
In allogeneic BMT, bone marrow from a genetically matched donor is used for the transplant. This type of BMT is often used in patients with leukemia, lymphoma, or other blood disorders who have failed other treatments.
Umbilical cord blood transplantation involves using stem cells from umbilical cord blood as a source of healthy bone marrow. This type of BMT is often used in children and adults who do not have a matched donor for allogeneic BMT.
The process of BMT typically involves several steps, including harvesting the bone marrow or stem cells from the donor, conditioning the patient's body to receive the new bone marrow or stem cells, transplanting the new bone marrow or stem cells into the patient's body, and monitoring the patient for signs of engraftment and complications.
BMT is a complex and potentially risky procedure that requires careful planning, preparation, and follow-up care. However, it can be a life-saving treatment for many patients with blood disorders or cancer.
Isoantigens are antigens that are present on the cells or tissues of one individual of a species, but are absent or different in another individual of the same species. They are also known as "alloantigens." Isoantigens are most commonly found on the surface of red blood cells and other tissues, and they can stimulate an immune response when transplanted into a different individual. This is because the recipient's immune system recognizes the isoantigens as foreign and mounts a defense against them. Isoantigens are important in the field of transplantation medicine, as they must be carefully matched between donor and recipient to reduce the risk of rejection.
Purinergic P2X5 receptors are a type of ionotropic purinergic receptor that are activated by adenosine triphosphate (ATP) and related nucleotides. They belong to the P2X receptor family, which includes seven subtypes (P2X1-7) that form trimeric channels permeable to cations such as calcium, sodium, and potassium.
The P2X5 receptor is composed of three identical subunits that contain two transmembrane domains, an intracellular N-terminus, and a large extracellular loop with conserved amino acid residues involved in ATP binding. The activation of P2X5 receptors leads to the opening of the ion channel, resulting in membrane depolarization and the initiation of downstream signaling pathways.
P2X5 receptors are widely expressed in various tissues, including the nervous system, immune system, and cardiovascular system. In the nervous system, they play important roles in pain sensation, neuroinflammation, and synaptic plasticity. In the immune system, P2X5 receptors regulate the activation and migration of immune cells, such as macrophages and dendritic cells. In the cardiovascular system, they contribute to the regulation of vascular tone and blood pressure.
Dysregulation of P2X5 receptor function has been implicated in various pathological conditions, including chronic pain, neurodegenerative diseases, and inflammatory disorders. Therefore, targeting P2X5 receptors represents a promising therapeutic strategy for the treatment of these conditions.
HLA-B38 Antigen is not a medical condition or disease, but rather a designation for a specific type of human leukocyte antigen (HLA) protein. HLAs are proteins found on the surface of cells that help the immune system distinguish between the body's own cells and foreign substances such as viruses and bacteria.
The HLA-B38 antigen is one of many different types of HLA-B antigens, which are a part of the major histocompatibility complex (MHC) class I molecules. These molecules present pieces of proteins from inside the cell to immune cells called T-cells, triggering an immune response if the protein is identified as foreign.
The HLA-B38 antigen is encoded by a specific gene variant known as HLA-B*38. This gene variant is relatively common in some populations and can be inherited from one or both parents. It has been associated with certain diseases, such as rheumatoid arthritis and certain types of cancer, but its role in these conditions is not fully understood.
It's important to note that HLA typing is a complex process that involves identifying specific genetic variations in the HLA genes. The presence or absence of a particular HLA antigen like HLA-B38 does not necessarily indicate the presence or absence of a particular disease, but may be one factor among many that contribute to an individual's overall risk.
Inbred strains of mice are defined as lines of mice that have been brother-sister mated for at least 20 consecutive generations. This results in a high degree of homozygosity, where the mice of an inbred strain are genetically identical to one another, with the exception of spontaneous mutations.
Inbred strains of mice are widely used in biomedical research due to their genetic uniformity and stability, which makes them useful for studying the genetic basis of various traits, diseases, and biological processes. They also provide a consistent and reproducible experimental system, as compared to outbred or genetically heterogeneous populations.
Some commonly used inbred strains of mice include C57BL/6J, BALB/cByJ, DBA/2J, and 129SvEv. Each strain has its own unique genetic background and phenotypic characteristics, which can influence the results of experiments. Therefore, it is important to choose the appropriate inbred strain for a given research question.
An antigen is a substance (usually a protein) that is recognized as foreign by the immune system and stimulates an immune response, leading to the production of antibodies or activation of T-cells. Antigens can be derived from various sources, including bacteria, viruses, fungi, parasites, and tumor cells. They can also come from non-living substances such as pollen, dust mites, or chemicals.
Antigens contain epitopes, which are specific regions on the antigen molecule that are recognized by the immune system. The immune system's response to an antigen depends on several factors, including the type of antigen, its size, and its location in the body.
In general, antigens can be classified into two main categories:
1. T-dependent antigens: These require the help of T-cells to stimulate an immune response. They are typically larger, more complex molecules that contain multiple epitopes capable of binding to both MHC class II molecules on antigen-presenting cells and T-cell receptors on CD4+ T-cells.
2. T-independent antigens: These do not require the help of T-cells to stimulate an immune response. They are usually smaller, simpler molecules that contain repetitive epitopes capable of cross-linking B-cell receptors and activating them directly.
Understanding antigens and their properties is crucial for developing vaccines, diagnostic tests, and immunotherapies.
HLA-A2 antigen is a type of human leukocyte antigen (HLA) class I molecule, which is found on the surface of cells in our body. HLA molecules are responsible for presenting pieces of proteins (peptides) from inside the cell to the immune system's T-cells, helping them distinguish between "self" and "non-self" proteins.
HLA-A2 is one of the most common HLA class I antigens in the Caucasian population, with an estimated frequency of around 50%. It presents a variety of peptides to T-cells, including those derived from viruses and tumor cells. The presentation of these peptides can trigger an immune response, leading to the destruction of infected or malignant cells.
It is important to note that HLA typing is crucial in organ transplantation, as a mismatch between donor and recipient HLA antigens can lead to rejection of the transplanted organ. Additionally, HLA-A2 has been associated with certain autoimmune diseases and cancer types, making it an area of interest for researchers studying these conditions.
An epitope is a specific region on the surface of an antigen (a molecule that can trigger an immune response) that is recognized by an antibody, B-cell receptor, or T-cell receptor. It is also commonly referred to as an antigenic determinant. Epitopes are typically composed of linear amino acid sequences or conformational structures made up of discontinuous amino acids in the antigen. They play a crucial role in the immune system's ability to differentiate between self and non-self molecules, leading to the targeted destruction of foreign substances like viruses and bacteria. Understanding epitopes is essential for developing vaccines, diagnostic tests, and immunotherapies.
Isoantibodies are antibodies produced by the immune system that recognize and react to antigens (markers) found on the cells or tissues of another individual of the same species. These antigens are typically proteins or carbohydrates present on the surface of red blood cells, but they can also be found on other cell types.
Isoantibodies are formed when an individual is exposed to foreign antigens, usually through blood transfusions, pregnancy, or tissue transplantation. The exposure triggers the immune system to produce specific antibodies against these antigens, which can cause a harmful immune response if the individual receives another transfusion or transplant from the same donor in the future.
There are two main types of isoantibodies:
1. Agglutinins: These are IgM antibodies that cause red blood cells to clump together (agglutinate) when mixed with the corresponding antigen. They develop rapidly after exposure and can cause immediate transfusion reactions or hemolytic disease of the newborn in pregnant women.
2. Hemolysins: These are IgG antibodies that destroy red blood cells by causing their membranes to become more permeable, leading to lysis (bursting) of the cells and release of hemoglobin into the plasma. They take longer to develop but can cause delayed transfusion reactions or hemolytic disease of the newborn in pregnant women.
Isoantibodies are detected through blood tests, such as the crossmatch test, which determines compatibility between a donor's and recipient's blood before transfusions or transplants.
Hematopoietic Stem Cell Transplantation (HSCT) is a medical procedure where hematopoietic stem cells (immature cells that give rise to all blood cell types) are transplanted into a patient. This procedure is often used to treat various malignant and non-malignant disorders affecting the hematopoietic system, such as leukemias, lymphomas, multiple myeloma, aplastic anemia, inherited immune deficiency diseases, and certain genetic metabolic disorders.
The transplantation can be autologous (using the patient's own stem cells), allogeneic (using stem cells from a genetically matched donor, usually a sibling or unrelated volunteer), or syngeneic (using stem cells from an identical twin).
The process involves collecting hematopoietic stem cells, most commonly from the peripheral blood or bone marrow. The collected cells are then infused into the patient after the recipient's own hematopoietic system has been ablated (or destroyed) using high-dose chemotherapy and/or radiation therapy. This allows the donor's stem cells to engraft, reconstitute, and restore the patient's hematopoietic system.
HSCT is a complex and potentially risky procedure with various complications, including graft-versus-host disease, infections, and organ damage. However, it offers the potential for cure or long-term remission in many patients with otherwise fatal diseases.
Cytotoxicity tests, immunologic are a group of laboratory assays used to measure the immune-mediated damage or destruction (cytotoxicity) of cells. These tests are often used in medical research and clinical settings to evaluate the potential toxicity of drugs, biological agents, or environmental factors on specific types of cells.
Immunologic cytotoxicity tests typically involve the use of immune effector cells, such as cytotoxic T lymphocytes (CTLs) or natural killer (NK) cells, which can recognize and kill target cells that express specific antigens on their surface. The tests may also involve the use of antibodies or other immune molecules that can bind to target cells and trigger complement-mediated cytotoxicity.
There are several types of immunologic cytotoxicity tests, including:
1. Cytotoxic T lymphocyte (CTL) assays: These tests measure the ability of CTLs to recognize and kill target cells that express specific antigens. The test involves incubating target cells with CTLs and then measuring the amount of cell death or damage.
2. Natural killer (NK) cell assays: These tests measure the ability of NK cells to recognize and kill target cells that lack self-antigens or express stress-induced antigens. The test involves incubating target cells with NK cells and then measuring the amount of cell death or damage.
3. Antibody-dependent cellular cytotoxicity (ADCC) assays: These tests measure the ability of antibodies to bind to target cells and recruit immune effector cells, such as NK cells or macrophages, to mediate cell lysis. The test involves incubating target cells with antibodies and then measuring the amount of cell death or damage.
4. Complement-dependent cytotoxicity (CDC) assays: These tests measure the ability of complement proteins to bind to target cells and form a membrane attack complex that leads to cell lysis. The test involves incubating target cells with complement proteins and then measuring the amount of cell death or damage.
Immunologic cytotoxicity tests are important tools in immunology, cancer research, and drug development. They can help researchers understand how immune cells recognize and kill infected or damaged cells, as well as how to develop new therapies that enhance or inhibit these processes.
Neoplasm antigens, also known as tumor antigens, are substances that are produced by cancer cells (neoplasms) and can stimulate an immune response. These antigens can be proteins, carbohydrates, or other molecules that are either unique to the cancer cells or are overexpressed or mutated versions of normal cellular proteins.
Neoplasm antigens can be classified into two main categories: tumor-specific antigens (TSAs) and tumor-associated antigens (TAAs). TSAs are unique to cancer cells and are not expressed by normal cells, while TAAs are present at low levels in normal cells but are overexpressed or altered in cancer cells.
TSAs can be further divided into viral antigens and mutated antigens. Viral antigens are produced when cancer is caused by a virus, such as human papillomavirus (HPV) in cervical cancer. Mutated antigens are the result of genetic mutations that occur during cancer development and are unique to each patient's tumor.
Neoplasm antigens play an important role in the immune response against cancer. They can be recognized by the immune system, leading to the activation of immune cells such as T cells and natural killer (NK) cells, which can then attack and destroy cancer cells. However, cancer cells often develop mechanisms to evade the immune response, allowing them to continue growing and spreading.
Understanding neoplasm antigens is important for the development of cancer immunotherapies, which aim to enhance the body's natural immune response against cancer. These therapies include checkpoint inhibitors, which block proteins that inhibit T cell activation, and therapeutic vaccines, which stimulate an immune response against specific tumor antigens.
C57BL/6 (C57 Black 6) is an inbred strain of laboratory mouse that is widely used in biomedical research. The term "inbred" refers to a strain of animals where matings have been carried out between siblings or other closely related individuals for many generations, resulting in a population that is highly homozygous at most genetic loci.
The C57BL/6 strain was established in 1920 by crossing a female mouse from the dilute brown (DBA) strain with a male mouse from the black strain. The resulting offspring were then interbred for many generations to create the inbred C57BL/6 strain.
C57BL/6 mice are known for their robust health, longevity, and ease of handling, making them a popular choice for researchers. They have been used in a wide range of biomedical research areas, including studies of cancer, immunology, neuroscience, cardiovascular disease, and metabolism.
One of the most notable features of the C57BL/6 strain is its sensitivity to certain genetic modifications, such as the introduction of mutations that lead to obesity or impaired glucose tolerance. This has made it a valuable tool for studying the genetic basis of complex diseases and traits.
Overall, the C57BL/6 inbred mouse strain is an important model organism in biomedical research, providing a valuable resource for understanding the genetic and molecular mechanisms underlying human health and disease.
CD8-positive T-lymphocytes, also known as CD8+ T cells or cytotoxic T cells, are a type of white blood cell that plays a crucial role in the adaptive immune system. They are named after the CD8 molecule found on their surface, which is a protein involved in cell signaling and recognition.
CD8+ T cells are primarily responsible for identifying and destroying virus-infected cells or cancerous cells. When activated, they release cytotoxic granules that contain enzymes capable of inducing apoptosis (programmed cell death) in the target cells. They also produce cytokines such as interferon-gamma, which can help coordinate the immune response and activate other immune cells.
CD8+ T cells are generated in the thymus gland and are a type of T cell, which is a lymphocyte that matures in the thymus and plays a central role in cell-mediated immunity. They recognize and respond to specific antigens presented on the surface of infected or cancerous cells in conjunction with major histocompatibility complex (MHC) class I molecules.
Overall, CD8+ T cells are an essential component of the immune system's defense against viral infections and cancer.
Graft rejection is an immune response that occurs when transplanted tissue or organ (the graft) is recognized as foreign by the recipient's immune system, leading to the activation of immune cells to attack and destroy the graft. This results in the failure of the transplant and the need for additional medical intervention or another transplant. There are three types of graft rejection: hyperacute, acute, and chronic. Hyperacute rejection occurs immediately or soon after transplantation due to pre-existing antibodies against the graft. Acute rejection typically occurs within weeks to months post-transplant and is characterized by the infiltration of T-cells into the graft. Chronic rejection, which can occur months to years after transplantation, is a slow and progressive process characterized by fibrosis and tissue damage due to ongoing immune responses against the graft.
BALB/c is an inbred strain of laboratory mouse that is widely used in biomedical research. The strain was developed at the Institute of Cancer Research in London by Henry Baldwin and his colleagues in the 1920s, and it has since become one of the most commonly used inbred strains in the world.
BALB/c mice are characterized by their black coat color, which is determined by a recessive allele at the tyrosinase locus. They are also known for their docile and friendly temperament, making them easy to handle and work with in the laboratory.
One of the key features of BALB/c mice that makes them useful for research is their susceptibility to certain types of tumors and immune responses. For example, they are highly susceptible to developing mammary tumors, which can be induced by chemical carcinogens or viral infection. They also have a strong Th2-biased immune response, which makes them useful models for studying allergic diseases and asthma.
BALB/c mice are also commonly used in studies of genetics, neuroscience, behavior, and infectious diseases. Because they are an inbred strain, they have a uniform genetic background, which makes it easier to control for genetic factors in experiments. Additionally, because they have been bred in the laboratory for many generations, they are highly standardized and reproducible, making them ideal subjects for scientific research.
Antigen presentation is the process by which certain cells in the immune system, known as antigen presenting cells (APCs), display foreign or abnormal proteins (antigens) on their surface to other immune cells, such as T-cells. This process allows the immune system to recognize and mount a response against harmful pathogens, infected or damaged cells.
There are two main types of antigen presentation: major histocompatibility complex (MHC) class I and MHC class II presentation.
1. MHC class I presentation: APCs, such as dendritic cells, macrophages, and B-cells, process and load antigens onto MHC class I molecules, which are expressed on the surface of almost all nucleated cells in the body. The MHC class I-antigen complex is then recognized by CD8+ T-cells (cytotoxic T-cells), leading to the destruction of infected or damaged cells.
2. MHC class II presentation: APCs, particularly dendritic cells and B-cells, process and load antigens onto MHC class II molecules, which are mainly expressed on the surface of professional APCs. The MHC class II-antigen complex is then recognized by CD4+ T-cells (helper T-cells), leading to the activation of other immune cells, such as B-cells and macrophages, to eliminate the pathogen or damaged cells.
In summary, antigen presentation is a crucial step in the adaptive immune response, allowing for the recognition and elimination of foreign or abnormal substances that could potentially harm the body.
1. Receptors: In the context of physiology and medicine, receptors are specialized proteins found on the surface of cells or inside cells that detect and respond to specific molecules, known as ligands. These interactions can trigger a range of responses within the cell, such as starting a signaling pathway or changing the cell's behavior. There are various types of receptors, including ion channels, G protein-coupled receptors, and enzyme-linked receptors.
2. Antigen: An antigen is any substance (usually a protein) that can be recognized by the immune system, specifically by antibodies or T-cells, as foreign and potentially harmful. Antigens can be derived from various sources, such as bacteria, viruses, fungi, parasites, or even non-living substances like pollen, chemicals, or toxins. An antigen typically contains epitopes, which are the specific regions that antibodies or T-cell receptors recognize and bind to.
3. T-Cell: Also known as T lymphocytes, T-cells are a type of white blood cell that plays a crucial role in cell-mediated immunity, a part of the adaptive immune system. They are produced in the bone marrow and mature in the thymus gland. There are several types of T-cells, including CD4+ helper T-cells, CD8+ cytotoxic T-cells, and regulatory T-cells (Tregs). T-cells recognize antigens presented to them by antigen-presenting cells (APCs) via their surface receptors called the T-cell receptor (TCR). Once activated, T-cells can proliferate and differentiate into various effector cells that help eliminate infected or damaged cells.
Oligopeptides are defined in medicine and biochemistry as short chains of amino acids, typically containing fewer than 20 amino acid residues. These small peptides are important components in various biological processes, such as serving as signaling molecules, enzyme inhibitors, or structural elements in some proteins. They can be found naturally in foods and may also be synthesized for use in medical research and therapeutic applications.
A clone is a group of cells that are genetically identical to each other because they are derived from a common ancestor cell through processes such as mitosis or asexual reproduction. Therefore, the term "clone cells" refers to a population of cells that are genetic copies of a single parent cell.
In the context of laboratory research, cells can be cloned by isolating a single cell and allowing it to divide in culture, creating a population of genetically identical cells. This is useful for studying the behavior and characteristics of individual cell types, as well as for generating large quantities of cells for use in experiments.
It's important to note that while clone cells are genetically identical, they may still exhibit differences in their phenotype (physical traits) due to epigenetic factors or environmental influences.
The spleen is an organ in the upper left side of the abdomen, next to the stomach and behind the ribs. It plays multiple supporting roles in the body:
1. It fights infection by acting as a filter for the blood. Old red blood cells are recycled in the spleen, and platelets and white blood cells are stored there.
2. The spleen also helps to control the amount of blood in the body by removing excess red blood cells and storing platelets.
3. It has an important role in immune function, producing antibodies and removing microorganisms and damaged red blood cells from the bloodstream.
The spleen can be removed without causing any significant problems, as other organs take over its functions. This is known as a splenectomy and may be necessary if the spleen is damaged or diseased.
Immunodominant epitopes refer to specific regions or segments on an antigen (a molecule that can trigger an immune response) that are particularly effective at stimulating an immune response. These epitopes are often the parts of the antigen that are most recognized by the immune system, and as a result, they elicit a strong response from immune cells such as T-cells or B-cells.
In the context of T-cell responses, immunodominant epitopes are typically short peptide sequences (usually 8-15 amino acids long) that are presented to T-cells by major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells. The T-cell receptor recognizes and binds to these epitopes, triggering a cascade of immune responses aimed at eliminating the pathogen or foreign substance that contains the antigen.
In some cases, immunodominant epitopes may be the primary targets of vaccines or other immunotherapies, as they can elicit strong and protective immune responses. However, in other cases, immunodominant epitopes may also be associated with immune evasion or tolerance, where the immune system fails to mount an effective response against a pathogen or cancer cell. Understanding the properties and behavior of immunodominant epitopes is therefore crucial for developing effective vaccines and immunotherapies.
An epitope is a specific region on an antigen (a substance that triggers an immune response) that is recognized and bound by an antibody or a T-cell receptor. In the case of T-lymphocytes, which are a type of white blood cell that plays a central role in cell-mediated immunity, epitopes are typically presented on the surface of infected cells in association with major histocompatibility complex (MHC) molecules.
T-lymphocytes recognize and respond to epitopes through their T-cell receptors (TCRs), which are membrane-bound proteins that can bind to specific epitopes presented on the surface of infected cells. There are two main types of T-lymphocytes: CD4+ T-cells, also known as helper T-cells, and CD8+ T-cells, also known as cytotoxic T-cells.
CD4+ T-cells recognize epitopes presented in the context of MHC class II molecules, which are typically expressed on the surface of professional antigen-presenting cells such as dendritic cells, macrophages, and B-cells. CD4+ T-cells help to coordinate the immune response by producing cytokines that activate other immune cells.
CD8+ T-cells recognize epitopes presented in the context of MHC class I molecules, which are expressed on the surface of almost all nucleated cells. CD8+ T-cells are able to directly kill infected cells by releasing cytotoxic granules that contain enzymes that can induce apoptosis (programmed cell death) in the target cell.
In summary, epitopes are specific regions on antigens that are recognized and bound by T-lymphocytes through their T-cell receptors. CD4+ T-cells recognize epitopes presented in the context of MHC class II molecules, while CD8+ T-cells recognize epitopes presented in the context of MHC class I molecules.
Immune tolerance, also known as immunological tolerance or specific immune tolerance, is a state of unresponsiveness or non-reactivity of the immune system towards a particular substance (antigen) that has the potential to elicit an immune response. This occurs when the immune system learns to distinguish "self" from "non-self" and does not attack the body's own cells, tissues, and organs.
In the context of transplantation, immune tolerance refers to the absence of a destructive immune response towards the transplanted organ or tissue, allowing for long-term graft survival without the need for immunosuppressive therapy. Immune tolerance can be achieved through various strategies, including hematopoietic stem cell transplantation, costimulation blockade, and regulatory T cell induction.
In summary, immune tolerance is a critical mechanism that prevents the immune system from attacking the body's own structures while maintaining the ability to respond appropriately to foreign pathogens and antigens.
A radiation chimera is not a widely used or recognized medical term. However, in the field of genetics and radiation biology, a "chimera" refers to an individual that contains cells with different genetic backgrounds. A radiation chimera, therefore, could refer to an organism that has become a chimera as a result of exposure to radiation, which can cause mutations and changes in the genetic makeup of cells.
Ionizing radiation, such as that used in cancer treatments or nuclear accidents, can cause DNA damage and mutations in cells. If an organism is exposed to radiation and some of its cells undergo mutations while others do not, this could result in a chimera with genetically distinct populations of cells.
However, it's important to note that the term "radiation chimera" is not commonly used in medical literature or clinical settings. If you encounter this term in a different context, I would recommend seeking clarification from the source to ensure a proper understanding.
'C3H' is the name of an inbred strain of laboratory mice that was developed at the Jackson Laboratory in Bar Harbor, Maine. The mice are characterized by their uniform genetic background and have been widely used in biomedical research for many decades.
The C3H strain is particularly notable for its susceptibility to certain types of cancer, including mammary tumors and lymphomas. It also has a high incidence of age-related macular degeneration and other eye diseases. The strain is often used in studies of immunology, genetics, and carcinogenesis.
Like all inbred strains, the C3H mice are the result of many generations of brother-sister matings, which leads to a high degree of genetic uniformity within the strain. This makes them useful for studying the effects of specific genes or environmental factors on disease susceptibility and other traits. However, it also means that they may not always be representative of the genetic diversity found in outbred populations, including humans.
Leukemia is a type of cancer that originates from the bone marrow - the soft, inner part of certain bones where new blood cells are made. It is characterized by an abnormal production of white blood cells, known as leukocytes or blasts. These abnormal cells accumulate in the bone marrow and interfere with the production of normal blood cells, leading to a decrease in red blood cells (anemia), platelets (thrombocytopenia), and healthy white blood cells (leukopenia).
There are several types of leukemia, classified based on the specific type of white blood cell affected and the speed at which the disease progresses:
1. Acute Leukemias - These types of leukemia progress rapidly, with symptoms developing over a few weeks or months. They involve the rapid growth and accumulation of immature, nonfunctional white blood cells (blasts) in the bone marrow and peripheral blood. The two main categories are:
- Acute Lymphoblastic Leukemia (ALL) - Originates from lymphoid progenitor cells, primarily affecting children but can also occur in adults.
- Acute Myeloid Leukemia (AML) - Develops from myeloid progenitor cells and is more common in older adults.
2. Chronic Leukemias - These types of leukemia progress slowly, with symptoms developing over a period of months to years. They involve the production of relatively mature, but still abnormal, white blood cells that can accumulate in large numbers in the bone marrow and peripheral blood. The two main categories are:
- Chronic Lymphocytic Leukemia (CLL) - Affects B-lymphocytes and is more common in older adults.
- Chronic Myeloid Leukemia (CML) - Originates from myeloid progenitor cells, characterized by the presence of a specific genetic abnormality called the Philadelphia chromosome. It can occur at any age but is more common in middle-aged and older adults.
Treatment options for leukemia depend on the type, stage, and individual patient factors. Treatments may include chemotherapy, targeted therapy, immunotherapy, stem cell transplantation, or a combination of these approaches.
A Lymphocyte Culture Test, Mixed (LCTM) is not a standardized medical test with a universally accepted definition. However, in some contexts, it may refer to a laboratory procedure where both T-lymphocytes and B-lymphocytes are cultured together from a sample of peripheral blood or other tissues. This test is sometimes used in research or specialized diagnostic settings to evaluate the immune function or to study the interactions between T-cells and B-cells in response to various stimuli, such as antigens or mitogens.
The test typically involves isolating lymphocytes from a sample, adding them to a culture medium along with appropriate stimulants, and then incubating the mixture for a period of time. The resulting responses, such as proliferation, differentiation, or production of cytokines, can be measured and analyzed to gain insights into the immune function or dysfunction.
It's important to note that LCTM is not a routine diagnostic test and its use and interpretation may vary depending on the specific laboratory or research setting.
An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.
Surface antigens are molecules found on the surface of cells that can be recognized by the immune system as being foreign or different from the host's own cells. Antigens are typically proteins or polysaccharides that are capable of stimulating an immune response, leading to the production of antibodies and activation of immune cells such as T-cells.
Surface antigens are important in the context of infectious diseases because they allow the immune system to identify and target infected cells for destruction. For example, viruses and bacteria often display surface antigens that are distinct from those found on host cells, allowing the immune system to recognize and attack them. In some cases, these surface antigens can also be used as targets for vaccines or other immunotherapies.
In addition to their role in infectious diseases, surface antigens are also important in the context of cancer. Tumor cells often display abnormal surface antigens that differ from those found on normal cells, allowing the immune system to potentially recognize and attack them. However, tumors can also develop mechanisms to evade the immune system, making it difficult to mount an effective response.
Overall, understanding the properties and behavior of surface antigens is crucial for developing effective immunotherapies and vaccines against infectious diseases and cancer.
Lymphocyte activation is the process by which B-cells and T-cells (types of lymphocytes) become activated to perform effector functions in an immune response. This process involves the recognition of specific antigens presented on the surface of antigen-presenting cells, such as dendritic cells or macrophages.
The activation of B-cells leads to their differentiation into plasma cells that produce antibodies, while the activation of T-cells results in the production of cytotoxic T-cells (CD8+ T-cells) that can directly kill infected cells or helper T-cells (CD4+ T-cells) that assist other immune cells.
Lymphocyte activation involves a series of intracellular signaling events, including the binding of co-stimulatory molecules and the release of cytokines, which ultimately result in the expression of genes involved in cell proliferation, differentiation, and effector functions. The activation process is tightly regulated to prevent excessive or inappropriate immune responses that can lead to autoimmunity or chronic inflammation.
CD4-positive T-lymphocytes, also known as CD4+ T cells or helper T cells, are a type of white blood cell that plays a crucial role in the immune response. They express the CD4 receptor on their surface and help coordinate the immune system's response to infectious agents such as viruses and bacteria.
CD4+ T cells recognize and bind to specific antigens presented by antigen-presenting cells, such as dendritic cells or macrophages. Once activated, they can differentiate into various subsets of effector cells, including Th1, Th2, Th17, and Treg cells, each with distinct functions in the immune response.
CD4+ T cells are particularly important in the immune response to HIV (human immunodeficiency virus), which targets and destroys these cells, leading to a weakened immune system and increased susceptibility to opportunistic infections. The number of CD4+ T cells is often used as a marker of disease progression in HIV infection, with lower counts indicating more advanced disease.
Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.
A lymphocyte transfusion is not a standard medical practice. However, the term "lymphocyte transfusion" generally refers to the infusion of lymphocytes, a type of white blood cell, from a donor to a recipient. This procedure is rarely performed and primarily used in research or experimental settings, such as in the context of adoptive immunotherapy for cancer treatment.
In adoptive immunotherapy, T lymphocytes (a subtype of lymphocytes) are collected from the patient or a donor, activated, expanded in the laboratory, and then reinfused into the patient to enhance their immune response against cancer cells. This is not a common procedure and should only be performed under the guidance of experienced medical professionals in specialized centers.
It's important to note that lymphocyte transfusions are different from stem cell or bone marrow transplants, which involve the infusion of hematopoietic stem cells to reconstitute the recipient's entire blood and immune system.
Adoptive immunotherapy is a type of cancer treatment that involves the removal of immune cells from a patient, followed by their modification and expansion in the laboratory, and then reinfusion back into the patient to help boost their immune system's ability to fight cancer. This approach can be used to enhance the natural ability of T-cells (a type of white blood cell) to recognize and destroy cancer cells.
There are different types of adoptive immunotherapy, including:
1. T-cell transfer therapy: In this approach, T-cells are removed from the patient's tumor or blood, activated and expanded in the laboratory, and then reinfused back into the patient. Some forms of T-cell transfer therapy involve genetically modifying the T-cells to express chimeric antigen receptors (CARs) that recognize specific proteins on the surface of cancer cells.
2. Tumor-infiltrating lymphocyte (TIL) therapy: This type of adoptive immunotherapy involves removing T-cells directly from a patient's tumor, expanding them in the laboratory, and then reinfusing them back into the patient. The expanded T-cells are specifically targeted to recognize and destroy cancer cells.
3. Dendritic cell (DC) vaccine: DCs are specialized immune cells that help activate T-cells. In this approach, DCs are removed from the patient, exposed to tumor antigens in the laboratory, and then reinfused back into the patient to stimulate a stronger immune response against cancer cells.
Adoptive immunotherapy has shown promise in treating certain types of cancer, such as melanoma and leukemia, but more research is needed to determine its safety and efficacy in other types of cancer.
Bacterial antigens are substances found on the surface or produced by bacteria that can stimulate an immune response in a host organism. These antigens can be proteins, polysaccharides, teichoic acids, lipopolysaccharides, or other molecules that are recognized as foreign by the host's immune system.
When a bacterial antigen is encountered by the host's immune system, it triggers a series of responses aimed at eliminating the bacteria and preventing infection. The host's immune system recognizes the antigen as foreign through the use of specialized receptors called pattern recognition receptors (PRRs), which are found on various immune cells such as macrophages, dendritic cells, and neutrophils.
Once a bacterial antigen is recognized by the host's immune system, it can stimulate both the innate and adaptive immune responses. The innate immune response involves the activation of inflammatory pathways, the recruitment of immune cells to the site of infection, and the production of antimicrobial peptides.
The adaptive immune response, on the other hand, involves the activation of T cells and B cells, which are specific to the bacterial antigen. These cells can recognize and remember the antigen, allowing for a more rapid and effective response upon subsequent exposures.
Bacterial antigens are important in the development of vaccines, as they can be used to stimulate an immune response without causing disease. By identifying specific bacterial antigens that are associated with virulence or pathogenicity, researchers can develop vaccines that target these antigens and provide protection against infection.
A tissue donor is an individual who has agreed to allow organs and tissues to be removed from their body after death for the purpose of transplantation to restore the health or save the life of another person. The tissues that can be donated include corneas, heart valves, skin, bone, tendons, ligaments, veins, and cartilage. These tissues can enhance the quality of life for many recipients and are often used in reconstructive surgeries. It is important to note that tissue donation does not interfere with an open casket funeral or other cultural or religious practices related to death and grieving.
HLA-DR antigens are a type of human leukocyte antigen (HLA) class II molecule that plays a crucial role in the immune system. They are found on the surface of antigen-presenting cells, such as dendritic cells, macrophages, and B lymphocytes. HLA-DR molecules present peptide antigens to CD4+ T cells, also known as helper T cells, thereby initiating an immune response.
HLA-DR antigens are highly polymorphic, meaning that there are many different variants of these molecules in the human population. This diversity allows for a wide range of potential peptide antigens to be presented and recognized by the immune system. HLA-DR antigens are encoded by genes located on chromosome 6 in the major histocompatibility complex (MHC) region.
In transplantation, HLA-DR compatibility between donor and recipient is an important factor in determining the success of the transplant. Incompatibility can lead to a heightened immune response against the transplanted organ or tissue, resulting in rejection. Additionally, certain HLA-DR types have been associated with increased susceptibility to autoimmune diseases, such as rheumatoid arthritis and multiple sclerosis.
B-lymphocytes, also known as B-cells, are a type of white blood cell that plays a key role in the immune system's response to infection. They are responsible for producing antibodies, which are proteins that help to neutralize or destroy pathogens such as bacteria and viruses.
When a B-lymphocyte encounters a pathogen, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies specific to the antigens on the surface of the pathogen. These antibodies bind to the pathogen, marking it for destruction by other immune cells such as neutrophils and macrophages.
B-lymphocytes also have a role in presenting antigens to T-lymphocytes, another type of white blood cell involved in the immune response. This helps to stimulate the activation and proliferation of T-lymphocytes, which can then go on to destroy infected cells or help to coordinate the overall immune response.
Overall, B-lymphocytes are an essential part of the adaptive immune system, providing long-lasting immunity to previously encountered pathogens and helping to protect against future infections.
A cell line is a culture of cells that are grown in a laboratory for use in research. These cells are usually taken from a single cell or group of cells, and they are able to divide and grow continuously in the lab. Cell lines can come from many different sources, including animals, plants, and humans. They are often used in scientific research to study cellular processes, disease mechanisms, and to test new drugs or treatments. Some common types of human cell lines include HeLa cells (which come from a cancer patient named Henrietta Lacks), HEK293 cells (which come from embryonic kidney cells), and HUVEC cells (which come from umbilical vein endothelial cells). It is important to note that cell lines are not the same as primary cells, which are cells that are taken directly from a living organism and have not been grown in the lab.
HLA-B antigens are human leukocyte antigen (HLA) proteins found on the surface of cells that play an important role in the body's immune system. They are part of the major histocompatibility complex (MHC) class I molecules, which present pieces of proteins from inside the cell to T-cells, a type of white blood cell involved in immune responses.
HLA-B antigens are highly polymorphic, meaning that there are many different variations or alleles of this gene in the human population. This genetic diversity allows for a wide range of potential HLA-B proteins to be expressed, which can help recognize and respond to a variety of foreign substances, such as viruses and cancer cells.
The HLA-B antigens are inherited from both parents, and an individual may express one or two different HLA-B antigens depending on their genetic makeup. The specific combination of HLA-B antigens that a person expresses can have implications for their susceptibility to certain diseases, as well as their compatibility with organ transplants.
Immunotherapy is a type of medical treatment that uses the body's own immune system to fight against diseases, such as cancer. It involves the use of substances (like vaccines, medications, or immune cells) that stimulate or suppress the immune system to help it recognize and destroy harmful disease-causing cells or agents, like tumor cells.
Immunotherapy can work in several ways:
1. Activating the immune system: Certain immunotherapies boost the body's natural immune responses, helping them recognize and attack cancer cells more effectively.
2. Suppressing immune system inhibitors: Some immunotherapies target and block proteins or molecules that can suppress the immune response, allowing the immune system to work more efficiently against diseases.
3. Replacing or enhancing specific immune cells: Immunotherapy can also involve administering immune cells (like T-cells) that have been genetically engineered or modified to recognize and destroy cancer cells.
Immunotherapies have shown promising results in treating various types of cancer, autoimmune diseases, and allergies. However, they can also cause side effects, as an overactive immune system may attack healthy tissues and organs. Therefore, careful monitoring is necessary during immunotherapy treatment.
A "Graft versus Host Reaction" (GVHR) is a condition that can occur after an organ or bone marrow transplant, where the immune cells in the graft (transplanted tissue) recognize and attack the recipient's (host's) tissues as foreign. This reaction occurs because the donor's immune cells (graft) are able to recognize the host's cells as different from their own due to differences in proteins called human leukocyte antigens (HLAs).
The GVHR can affect various organs, including the skin, liver, gastrointestinal tract, and lungs. Symptoms may include rash, diarrhea, jaundice, and respiratory distress. The severity of the reaction can vary widely, from mild to life-threatening.
To prevent or reduce the risk of GVHR, immunosuppressive drugs are often given to the recipient before and after transplantation to suppress their immune system and prevent it from attacking the graft. Despite these measures, GVHR can still occur in some cases, particularly when there is a significant mismatch between the donor and recipient HLAs.
Flow cytometry is a medical and research technique used to measure physical and chemical characteristics of cells or particles, one cell at a time, as they flow in a fluid stream through a beam of light. The properties measured include:
* Cell size (light scatter)
* Cell internal complexity (granularity, also light scatter)
* Presence or absence of specific proteins or other molecules on the cell surface or inside the cell (using fluorescent antibodies or other fluorescent probes)
The technique is widely used in cell counting, cell sorting, protein engineering, biomarker discovery and monitoring disease progression, particularly in hematology, immunology, and cancer research.
Major Histocompatibility Complex (MHC) Class II genes are a group of genes that encode cell surface proteins responsible for presenting peptide antigens to CD4+ T cells, which are crucial in the adaptive immune response. These proteins are expressed mainly on professional antigen-presenting cells such as dendritic cells, macrophages, and B cells. MHC Class II molecules present extracellular antigens derived from bacteria, viruses, and other pathogens, facilitating the activation of appropriate immune responses to eliminate the threat. The genes responsible for these proteins are found within the MHC locus on chromosome 6 in humans (chromosome 17 in mice).
An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.
Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.
For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.
Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.
An antigen is any substance that can stimulate an immune response, particularly the production of antibodies. Viral antigens are antigens that are found on or produced by viruses. They can be proteins, glycoproteins, or carbohydrates present on the surface or inside the viral particle.
Viral antigens play a crucial role in the immune system's recognition and response to viral infections. When a virus infects a host cell, it may display its antigens on the surface of the infected cell. This allows the immune system to recognize and target the infected cells for destruction, thereby limiting the spread of the virus.
Viral antigens are also important targets for vaccines. Vaccines typically work by introducing a harmless form of a viral antigen to the body, which then stimulates the production of antibodies and memory T-cells that can recognize and respond quickly and effectively to future infections with the actual virus.
It's worth noting that different types of viruses have different antigens, and these antigens can vary between strains of the same virus. This is why there are often different vaccines available for different viral diseases, and why flu vaccines need to be updated every year to account for changes in the circulating influenza virus strains.
Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.
Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.
Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.
A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.
Interferon-gamma (IFN-γ) is a soluble cytokine that is primarily produced by the activation of natural killer (NK) cells and T lymphocytes, especially CD4+ Th1 cells and CD8+ cytotoxic T cells. It plays a crucial role in the regulation of the immune response against viral and intracellular bacterial infections, as well as tumor cells. IFN-γ has several functions, including activating macrophages to enhance their microbicidal activity, increasing the presentation of major histocompatibility complex (MHC) class I and II molecules on antigen-presenting cells, stimulating the proliferation and differentiation of T cells and NK cells, and inducing the production of other cytokines and chemokines. Additionally, IFN-γ has direct antiproliferative effects on certain types of tumor cells and can enhance the cytotoxic activity of immune cells against infected or malignant cells.
HLA-D antigens, also known as HLA class II antigens, are a group of proteins found on the surface of cells that play an important role in the immune system. "HLA" stands for Human Leukocyte Antigen, which is a part of the major histocompatibility complex (MHC) in humans.
HLA-D antigens are primarily expressed by immune cells such as B lymphocytes, macrophages, and dendritic cells, but they can also be found on other cell types under certain conditions. These antigens help the immune system distinguish between "self" and "non-self" by presenting pieces of proteins (peptides) from both inside and outside the cell to T lymphocytes, a type of white blood cell that is crucial for mounting an immune response.
HLA-D antigens are divided into three subtypes: HLA-DP, HLA-DQ, and HLA-DR. Each subtype has a specific function in presenting peptides to T lymphocytes. The genes that encode HLA-D antigens are highly polymorphic, meaning there are many different variations of these genes in the population. This genetic diversity allows for a better match between an individual's immune system and the wide variety of pathogens they may encounter.
Abnormalities in HLA-D antigens have been associated with several autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. Additionally, certain variations in HLA-D genes can influence the severity of infectious diseases, such as HIV/AIDS and hepatitis C.
1. Receptors: In the context of physiology and medicine, receptors are specialized proteins found on the surface of cells or inside cells that detect and respond to specific molecules, known as ligands. Receptors play a crucial role in signal transduction, enabling cells to communicate with each other and respond to changes in their environment.
2. Antigen: An antigen is any substance (usually a protein) that can be recognized by the immune system and stimulate an immune response. Antigens can be foreign substances such as bacteria, viruses, or pollen, or they can be components of our own cells, such as tumor antigens in cancer cells. Antigens are typically bound and presented to the immune system by specialized cells called antigen-presenting cells (APCs).
3. T-Cell: T-cells, also known as T lymphocytes, are a type of white blood cell that plays a central role in cell-mediated immunity. T-cells are produced in the bone marrow and mature in the thymus gland. There are two main types of T-cells: CD4+ helper T-cells and CD8+ cytotoxic T-cells. Helper T-cells assist other immune cells, such as B-cells and macrophages, in mounting an immune response, while cytotoxic T-cells directly kill infected or cancerous cells.
4. Alpha-Beta: Alpha-beta is a type of T-cell receptor (TCR) that is found on the surface of most mature T-cells. The alpha-beta TCR is composed of two polypeptide chains, an alpha chain and a beta chain, that are held together by disulfide bonds. The alpha-beta TCR recognizes and binds to specific antigens presented in the context of major histocompatibility complex (MHC) molecules on the surface of APCs. This interaction is critical for initiating an immune response against infected or cancerous cells.
Beta-2 microglobulin (β2M) is a small protein that is a component of the major histocompatibility complex class I molecule, which plays a crucial role in the immune system. It is found on the surface of almost all nucleated cells in the body and is involved in presenting intracellular peptides to T-cells for immune surveillance.
β2M is produced at a relatively constant rate by cells throughout the body and is freely filtered by the glomeruli in the kidneys. Under normal circumstances, most of the filtrated β2M is reabsorbed and catabolized in the proximal tubules of the nephrons. However, when the glomerular filtration rate (GFR) is decreased, as in chronic kidney disease (CKD), the reabsorption capacity of the proximal tubules becomes overwhelmed, leading to increased levels of β2M in the blood and its subsequent appearance in the urine.
Elevated serum and urinary β2M levels have been associated with various clinical conditions, such as CKD, multiple myeloma, autoimmune disorders, and certain infectious diseases. Measuring β2M concentrations can provide valuable information for diagnostic, prognostic, and monitoring purposes in these contexts.
Graft survival, in medical terms, refers to the success of a transplanted tissue or organ in continuing to function and integrate with the recipient's body over time. It is the opposite of graft rejection, which occurs when the recipient's immune system recognizes the transplanted tissue as foreign and attacks it, leading to its failure.
Graft survival depends on various factors, including the compatibility between the donor and recipient, the type and location of the graft, the use of immunosuppressive drugs to prevent rejection, and the overall health of the recipient. A successful graft survival implies that the transplanted tissue or organ has been accepted by the recipient's body and is functioning properly, providing the necessary physiological support for the recipient's survival and improved quality of life.
Immunogenetics is the study of the genetic basis of immune responses. It involves the investigation of the genetic factors that control the development, function, and regulation of the immune system, as well as the genetic mechanisms underlying immune-mediated diseases such as autoimmune disorders, allergies, and transplant rejection. This field combines immunology, genetics, and molecular biology to understand how genes contribute to immune response variability among individuals and populations.
Histocompatibility antigen H-2D is a type of major histocompatibility complex (MHC) class I molecule found in mice. It is a transmembrane protein located on the surface of nucleated cells, which plays a crucial role in the adaptive immune system. The primary function of H-2D is to present endogenous peptide antigens to CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs).
H-2D molecules are encoded by genes within the H-2D region of the MHC on chromosome 17. These genes have multiple alleles, resulting in a high degree of polymorphism, which contributes to the diversity of the immune response among different mouse strains. The peptide-binding groove of H-2D molecules is formed by two alpha helices and eight beta pleats, creating a specific binding site for antigenic peptides.
The peptides presented by H-2D molecules are derived from intracellular proteins that undergo degradation in the proteasome. These peptides are then transported into the endoplasmic reticulum, where they bind to H-2D molecules with the assistance of chaperone proteins like tapasin and calreticulin. The H-2D-peptide complex is then transported to the cell surface for presentation to CD8+ T cells.
Recognition of H-2D-peptide complexes by CD8+ T cells leads to their activation, proliferation, and differentiation into effector CTLs. Activated CTLs can recognize and eliminate virus-infected or malignant cells displaying specific H-2D-peptide complexes, thereby playing a critical role in the cell-mediated immune response.
In summary, histocompatibility antigen H-2D is a polymorphic MHC class I molecule in mice that presents endogenous peptide antigens to CD8+ T cells, contributing significantly to the adaptive immune response and the elimination of infected or malignant cells.
"Cells, cultured" is a medical term that refers to cells that have been removed from an organism and grown in controlled laboratory conditions outside of the body. This process is called cell culture and it allows scientists to study cells in a more controlled and accessible environment than they would have inside the body. Cultured cells can be derived from a variety of sources, including tissues, organs, or fluids from humans, animals, or cell lines that have been previously established in the laboratory.
Cell culture involves several steps, including isolation of the cells from the tissue, purification and characterization of the cells, and maintenance of the cells in appropriate growth conditions. The cells are typically grown in specialized media that contain nutrients, growth factors, and other components necessary for their survival and proliferation. Cultured cells can be used for a variety of purposes, including basic research, drug development and testing, and production of biological products such as vaccines and gene therapies.
It is important to note that cultured cells may behave differently than they do in the body, and results obtained from cell culture studies may not always translate directly to human physiology or disease. Therefore, it is essential to validate findings from cell culture experiments using additional models and ultimately in clinical trials involving human subjects.
Beta-globulins are a group of proteins found in the beta region of a serum protein electrophoresis, which is a laboratory test used to separate and identify different types of proteins in the blood. This group includes several important proteins such as:
1. Beta-lipoproteins: These are responsible for transporting fat molecules, including cholesterol, throughout the body.
2. Transferrin: A protein that binds and transports iron in the blood.
3. Complement components: These proteins play a crucial role in the immune system's response to infection and inflammation.
4. Beta-2 microglobulin: A protein involved in the functioning of the immune system, elevated levels of which can be found in various conditions such as kidney disease and autoimmune disorders.
5. Hemopexin: A protein that binds and transports heme (a component of hemoglobin) in the blood.
It is important to note that any significant increase or decrease in beta-globulins can indicate an underlying medical condition, such as liver disease, kidney disease, or an autoimmune disorder. Therefore, abnormal results should be further evaluated by a healthcare professional for proper diagnosis and treatment.
Chronic myelogenous leukemia (CML), BCR-ABL positive is a specific subtype of leukemia that originates in the bone marrow and involves the excessive production of mature granulocytes, a type of white blood cell. It is characterized by the presence of the Philadelphia chromosome, which is formed by a genetic translocation between chromosomes 9 and 22, resulting in the formation of the BCR-ABL fusion gene. This gene encodes for an abnormal protein with increased tyrosine kinase activity, leading to uncontrolled cell growth and division. The presence of this genetic abnormality is used to confirm the diagnosis and guide treatment decisions.
Leukemia, myeloid is a type of cancer that originates in the bone marrow, where blood cells are produced. Myeloid leukemia affects the myeloid cells, which include red blood cells, platelets, and most types of white blood cells. In this condition, the bone marrow produces abnormal myeloid cells that do not mature properly and accumulate in the bone marrow and blood. These abnormal cells hinder the production of normal blood cells, leading to various symptoms such as anemia, fatigue, increased risk of infections, and easy bruising or bleeding.
There are several types of myeloid leukemias, including acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). AML progresses rapidly and requires immediate treatment, while CML tends to progress more slowly. The exact causes of myeloid leukemia are not fully understood, but risk factors include exposure to radiation or certain chemicals, smoking, genetic disorders, and a history of chemotherapy or other cancer treatments.
Major Histocompatibility Complex (MHC) class I genes are a group of genes that encode proteins found on the surface of most nucleated cells in the body. These proteins play a crucial role in the immune system by presenting pieces of protein from inside the cell to T-cells, which are a type of white blood cell. This process allows the immune system to detect and respond to cells that have been infected by viruses or become cancerous.
MHC class I genes are highly polymorphic, meaning there are many different variations of these genes in the population. This diversity is important for the immune system's ability to recognize and respond to a wide variety of pathogens. The MHC class I proteins are composed of three main regions: the heavy chain, which is encoded by the MHC class I gene; a short peptide, which is derived from inside the cell; and a light chain called beta-2 microglobulin, which is not encoded by an MHC gene.
There are three major types of MHC class I genes in humans, known as HLA-A, HLA-B, and HLA-C. These genes are located on chromosome 6 and are among the most polymorphic genes in the human genome. The products of these genes are critical for the immune system's ability to distinguish between self and non-self, and play a key role in organ transplant rejection.
Antigen-presenting cells (APCs) are a group of specialized cells in the immune system that play a critical role in initiating and regulating immune responses. They have the ability to engulf, process, and present antigens (molecules derived from pathogens or other foreign substances) on their surface in conjunction with major histocompatibility complex (MHC) molecules. This presentation of antigens allows APCs to activate T cells, which are crucial for adaptive immunity.
There are several types of APCs, including:
1. Dendritic cells (DCs): These are the most potent and professional APCs, found in various tissues throughout the body. DCs can capture antigens from their environment, process them, and migrate to lymphoid organs where they present antigens to T cells.
2. Macrophages: These large phagocytic cells are found in many tissues and play a role in both innate and adaptive immunity. They can engulf and digest pathogens, then present processed antigens on their MHC class II molecules to activate CD4+ T helper cells.
3. B cells: These are primarily responsible for humoral immune responses by producing antibodies against antigens. When activated, B cells can also function as APCs and present antigens on their MHC class II molecules to CD4+ T cells.
The interaction between APCs and T cells is critical for the development of an effective immune response against pathogens or other foreign substances. This process helps ensure that the immune system can recognize and eliminate threats while minimizing damage to healthy tissues.
CD8 antigens are a type of protein found on the surface of certain immune cells called cytotoxic T lymphocytes or cytotoxic T cells. These cells play a critical role in the adaptive immune response, which is the specific and targeted response of the immune system to foreign substances (antigens) that invade the body.
CD8 antigens help cytotoxic T cells recognize and respond to infected or abnormal cells, such as those that have been infected by a virus or have become cancerous. When a cytotoxic T cell encounters a cell displaying a specific antigen bound to a CD8 molecule, it becomes activated and releases toxic substances that can kill the target cell.
CD8 antigens are also known as cluster of differentiation 8 antigens or CD8 receptors. They belong to a larger family of proteins called major histocompatibility complex class I (MHC class I) molecules, which present antigens to T cells and play a crucial role in the immune system's ability to distinguish between self and non-self.
T-lymphocyte subsets refer to distinct populations of T-cells, which are a type of white blood cell that plays a central role in cell-mediated immunity. The two main types of T-lymphocytes are CD4+ and CD8+ cells, which are defined by the presence or absence of specific proteins called cluster differentiation (CD) molecules on their surface.
CD4+ T-cells, also known as helper T-cells, play a crucial role in activating other immune cells, such as B-lymphocytes and macrophages, to mount an immune response against pathogens. They also produce cytokines that help regulate the immune response.
CD8+ T-cells, also known as cytotoxic T-cells, directly kill infected cells or tumor cells by releasing toxic substances such as perforins and granzymes.
The balance between these two subsets of T-cells is critical for maintaining immune homeostasis and mounting effective immune responses against pathogens while avoiding excessive inflammation and autoimmunity. Therefore, the measurement of T-lymphocyte subsets is essential in diagnosing and monitoring various immunological disorders, including HIV infection, cancer, and autoimmune diseases.
Hematologic neoplasms, also known as hematological malignancies, are a group of diseases characterized by the uncontrolled growth and accumulation of abnormal blood cells or bone marrow cells. These disorders can originate from the myeloid or lymphoid cell lines, which give rise to various types of blood cells, including red blood cells, white blood cells, and platelets.
Hematologic neoplasms can be broadly classified into three categories:
1. Leukemias: These are cancers that primarily affect the bone marrow and blood-forming tissues. They result in an overproduction of abnormal white blood cells, which interfere with the normal functioning of the blood and immune system. There are several types of leukemia, including acute lymphoblastic leukemia (ALL), chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML).
2. Lymphomas: These are cancers that develop from the lymphatic system, which is a part of the immune system responsible for fighting infections. Lymphomas can affect lymph nodes, spleen, bone marrow, and other organs. The two main types of lymphoma are Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL).
3. Myelomas: These are cancers that arise from the plasma cells, a type of white blood cell responsible for producing antibodies. Multiple myeloma is the most common type of myeloma, characterized by an excessive proliferation of malignant plasma cells in the bone marrow, leading to the production of abnormal amounts of monoclonal immunoglobulins (M proteins) and bone destruction.
Hematologic neoplasms can have various symptoms, such as fatigue, weakness, frequent infections, easy bruising or bleeding, weight loss, swollen lymph nodes, and bone pain. The diagnosis typically involves a combination of medical history, physical examination, laboratory tests, imaging studies, and sometimes bone marrow biopsy. Treatment options depend on the type and stage of the disease and may include chemotherapy, radiation therapy, targeted therapy, immunotherapy, stem cell transplantation, or a combination of these approaches.
Genetic polymorphism refers to the occurrence of multiple forms (called alleles) of a particular gene within a population. These variations in the DNA sequence do not generally affect the function or survival of the organism, but they can contribute to differences in traits among individuals. Genetic polymorphisms can be caused by single nucleotide changes (SNPs), insertions or deletions of DNA segments, or other types of genetic rearrangements. They are important for understanding genetic diversity and evolution, as well as for identifying genetic factors that may contribute to disease susceptibility in humans.
"CBA" is an abbreviation for a specific strain of inbred mice that were developed at the Cancer Research Institute in London. The "Inbred CBA" mice are genetically identical individuals within the same strain, due to many generations of brother-sister matings. This results in a homozygous population, making them valuable tools for research because they reduce variability and increase reproducibility in experimental outcomes.
The CBA strain is known for its susceptibility to certain diseases, such as autoimmune disorders and cancer, which makes it a popular choice for researchers studying those conditions. Additionally, the CBA strain has been widely used in studies related to transplantation immunology, infectious diseases, and genetic research.
It's important to note that while "Inbred CBA" mice are a well-established and useful tool in biomedical research, they represent only one of many inbred strains available for scientific investigation. Each strain has its own unique characteristics and advantages, depending on the specific research question being asked.
Lymphocytes are a type of white blood cell that is an essential part of the immune system. They are responsible for recognizing and responding to potentially harmful substances such as viruses, bacteria, and other foreign invaders. There are two main types of lymphocytes: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).
B-lymphocytes produce antibodies, which are proteins that help to neutralize or destroy foreign substances. When a B-cell encounters a foreign substance, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies. These antibodies bind to the foreign substance, marking it for destruction by other immune cells.
T-lymphocytes, on the other hand, are involved in cell-mediated immunity. They directly attack and destroy infected cells or cancerous cells. T-cells can also help to regulate the immune response by producing chemical signals that activate or inhibit other immune cells.
Lymphocytes are produced in the bone marrow and mature in either the bone marrow (B-cells) or the thymus gland (T-cells). They circulate throughout the body in the blood and lymphatic system, where they can be found in high concentrations in lymph nodes, the spleen, and other lymphoid organs.
Abnormalities in the number or function of lymphocytes can lead to a variety of immune-related disorders, including immunodeficiency diseases, autoimmune disorders, and cancer.
Hematopoietic stem cells (HSCs) are immature, self-renewing cells that give rise to all the mature blood and immune cells in the body. They are capable of both producing more hematopoietic stem cells (self-renewal) and differentiating into early progenitor cells that eventually develop into red blood cells, white blood cells, and platelets. HSCs are found in the bone marrow, umbilical cord blood, and peripheral blood. They have the ability to repair damaged tissues and offer significant therapeutic potential for treating various diseases, including hematological disorders, genetic diseases, and cancer.
Immunologic graft enhancement refers to the manipulation of the immune system to increase the acceptance and survival of a transplanted tissue or organ (graft) in the recipient's body. This is achieved by suppressing the immune response that recognizes and attacks the graft as foreign, thereby reducing the risk of rejection.
Various strategies can be used for immunologic graft enhancement, including:
1. Immunosuppressive therapy: The use of medications to inhibit the activity of the immune system and prevent it from attacking the graft. Commonly used drugs include corticosteroids, calcineurin inhibitors, antiproliferative agents, and monoclonal antibodies.
2. Induction therapy: The administration of high doses of immunosuppressive drugs before or immediately after transplantation to suppress the initial immune response and reduce the risk of early rejection.
3. Tolerance induction: The manipulation of the recipient's immune system to promote tolerance to the graft, allowing for long-term acceptance without the need for ongoing immunosuppression. This can be achieved through various methods, such as costimulatory blockade, regulatory T cell therapy, or mixed chimerism.
4. Desensitization: The reduction of antibodies against the graft in sensitized recipients, who have previously been exposed to foreign antigens and developed an immune response. This can be achieved through various methods, such as plasmapheresis, intravenous immunoglobulin therapy, or protein A immunoabsorption.
It is important to note that while these strategies can enhance graft survival and reduce the risk of rejection, they also increase the risk of infection and malignancy due to the suppression of the immune system. Therefore, careful monitoring and management of the recipient's immune status is essential for successful transplantation outcomes.
Monoclonal antibodies are a type of antibody that are identical because they are produced by a single clone of cells. They are laboratory-produced molecules that act like human antibodies in the immune system. They can be designed to attach to specific proteins found on the surface of cancer cells, making them useful for targeting and treating cancer. Monoclonal antibodies can also be used as a therapy for other diseases, such as autoimmune disorders and inflammatory conditions.
Monoclonal antibodies are produced by fusing a single type of immune cell, called a B cell, with a tumor cell to create a hybrid cell, or hybridoma. This hybrid cell is then able to replicate indefinitely, producing a large number of identical copies of the original antibody. These antibodies can be further modified and engineered to enhance their ability to bind to specific targets, increase their stability, and improve their effectiveness as therapeutic agents.
Monoclonal antibodies have several mechanisms of action in cancer therapy. They can directly kill cancer cells by binding to them and triggering an immune response. They can also block the signals that promote cancer growth and survival. Additionally, monoclonal antibodies can be used to deliver drugs or radiation directly to cancer cells, increasing the effectiveness of these treatments while minimizing their side effects on healthy tissues.
Monoclonal antibodies have become an important tool in modern medicine, with several approved for use in cancer therapy and other diseases. They are continuing to be studied and developed as a promising approach to treating a wide range of medical conditions.
Dendritic cells (DCs) are a type of immune cell that play a critical role in the body's defense against infection and cancer. They are named for their dendrite-like projections, which they use to interact with and sample their environment. DCs are responsible for processing antigens (foreign substances that trigger an immune response) and presenting them to T cells, a type of white blood cell that plays a central role in the immune system's response to infection and cancer.
DCs can be found throughout the body, including in the skin, mucous membranes, and lymphoid organs. They are able to recognize and respond to a wide variety of antigens, including those from bacteria, viruses, fungi, and parasites. Once they have processed an antigen, DCs migrate to the lymph nodes, where they present the antigen to T cells. This interaction activates the T cells, which then go on to mount a targeted immune response against the invading pathogen or cancerous cells.
DCs are a diverse group of cells that can be divided into several subsets based on their surface markers and function. Some DCs, such as Langerhans cells and dermal DCs, are found in the skin and mucous membranes, where they serve as sentinels for invading pathogens. Other DCs, such as plasmacytoid DCs and conventional DCs, are found in the lymphoid organs, where they play a role in activating T cells and initiating an immune response.
Overall, dendritic cells are essential for the proper functioning of the immune system, and dysregulation of these cells has been implicated in a variety of diseases, including autoimmune disorders and cancer.
An acute disease is a medical condition that has a rapid onset, develops quickly, and tends to be short in duration. Acute diseases can range from minor illnesses such as a common cold or flu, to more severe conditions such as pneumonia, meningitis, or a heart attack. These types of diseases often have clear symptoms that are easy to identify, and they may require immediate medical attention or treatment.
Acute diseases are typically caused by an external agent or factor, such as a bacterial or viral infection, a toxin, or an injury. They can also be the result of a sudden worsening of an existing chronic condition. In general, acute diseases are distinct from chronic diseases, which are long-term medical conditions that develop slowly over time and may require ongoing management and treatment.
Examples of acute diseases include:
* Acute bronchitis: a sudden inflammation of the airways in the lungs, often caused by a viral infection.
* Appendicitis: an inflammation of the appendix that can cause severe pain and requires surgical removal.
* Gastroenteritis: an inflammation of the stomach and intestines, often caused by a viral or bacterial infection.
* Migraine headaches: intense headaches that can last for hours or days, and are often accompanied by nausea, vomiting, and sensitivity to light and sound.
* Myocardial infarction (heart attack): a sudden blockage of blood flow to the heart muscle, often caused by a buildup of plaque in the coronary arteries.
* Pneumonia: an infection of the lungs that can cause coughing, chest pain, and difficulty breathing.
* Sinusitis: an inflammation of the sinuses, often caused by a viral or bacterial infection.
It's important to note that while some acute diseases may resolve on their own with rest and supportive care, others may require medical intervention or treatment to prevent complications and promote recovery. If you are experiencing symptoms of an acute disease, it is always best to seek medical attention to ensure proper diagnosis and treatment.
Corneal transplantation, also known as keratoplasty, is a surgical procedure in which all or part of a damaged or diseased cornea is replaced with healthy corneal tissue from a deceased donor. The cornea is the clear, dome-shaped surface at the front of the eye that plays an important role in focusing vision. When it becomes cloudy or misshapen due to injury, infection, or inherited conditions, vision can become significantly impaired.
During the procedure, the surgeon carefully removes a circular section of the damaged cornea and replaces it with a similarly sized piece of donor tissue. The new cornea is then stitched into place using very fine sutures that are typically removed several months after surgery.
Corneal transplantation has a high success rate, with more than 90% of procedures resulting in improved vision. However, as with any surgical procedure, there are risks involved, including infection, rejection of the donor tissue, and bleeding. Regular follow-up care is essential to monitor for any signs of complications and ensure proper healing.
Single Nucleotide Polymorphism (SNP) is a type of genetic variation that occurs when a single nucleotide (A, T, C, or G) in the DNA sequence is altered. This alteration must occur in at least 1% of the population to be considered a SNP. These variations can help explain why some people are more susceptible to certain diseases than others and can also influence how an individual responds to certain medications. SNPs can serve as biological markers, helping scientists locate genes that are associated with disease. They can also provide information about an individual's ancestry and ethnic background.
An antigen-antibody reaction is a specific immune response that occurs when an antigen (a foreign substance, such as a protein or polysaccharide on the surface of a bacterium or virus) comes into contact with a corresponding antibody (a protective protein produced by the immune system in response to the antigen). The antigen and antibody bind together, forming an antigen-antibody complex. This interaction can neutralize the harmful effects of the antigen, mark it for destruction by other immune cells, or activate complement proteins to help eliminate the antigen from the body. Antigen-antibody reactions are a crucial part of the adaptive immune response and play a key role in the body's defense against infection and disease.
HLA-C antigens are a type of human leukocyte antigen (HLA) found on the surface of cells in the human body. They are part of the major histocompatibility complex (MHC) class I molecules, which play a critical role in the immune system's ability to differentiate between "self" and "non-self" cells.
HLA-C antigens are responsible for presenting peptide fragments from inside the cell to CD8+ T cells, also known as cytotoxic T lymphocytes (CTLs). This presentation allows the CTLs to recognize and destroy infected or damaged cells, helping to prevent the spread of viruses and other pathogens.
Like other HLA antigens, HLA-C antigens are highly polymorphic, meaning that there are many different variations of these molecules in the human population. This diversity allows for a better match between an individual's immune system and the pathogens they encounter, increasing the chances of mounting an effective immune response. However, this same diversity can also make it more challenging to find compatible organ donors for transplantation.
CD (cluster of differentiation) antigens are cell-surface proteins that are expressed on leukocytes (white blood cells) and can be used to identify and distinguish different subsets of these cells. They are important markers in the field of immunology and hematology, and are commonly used to diagnose and monitor various diseases, including cancer, autoimmune disorders, and infectious diseases.
CD antigens are designated by numbers, such as CD4, CD8, CD19, etc., which refer to specific proteins found on the surface of different types of leukocytes. For example, CD4 is a protein found on the surface of helper T cells, while CD8 is found on cytotoxic T cells.
CD antigens can be used as targets for immunotherapy, such as monoclonal antibody therapy, in which antibodies are designed to bind to specific CD antigens and trigger an immune response against cancer cells or infected cells. They can also be used as markers to monitor the effectiveness of treatments and to detect minimal residual disease (MRD) after treatment.
It's important to note that not all CD antigens are exclusive to leukocytes, some can be found on other cell types as well, and their expression can vary depending on the activation state or differentiation stage of the cells.
Minor histocompatibility antigen
RESF1
BCL2-related protein A1
HMHA1
Antigen
HM13
STT3B
PUM3
MHC multimer
DDX3Y
KDM5D
ABCA7
Thymosin beta-4, Y-chromosomal
UTY (gene)
MYO1G
Sidrón Cave
AKAP13
Veto cells
CENPM
Els Goulmy
Elizabeth Simpson (biologist)
Polly Matzinger
H-Y antigen
Graft-versus-tumor effect
Graft-versus-host disease
Recurrent miscarriage
Transplant rejection
Signal peptide peptidase
Bruce Beutler
Index of immunology articles
Minor histocompatibility antigen - Wikipedia
Description of first non-human primate minor histocompatibility antigen
Construction and molecular characterization of a T-cell receptor-like antibody and CAR-T cells specific for minor...
Lipopolysaccharide-induced M2 to M1 macrophage transformation for IL-12p70 production is blocked by Candida albicans mediated...
Past Events - Universität Ulm
Graft Versus Host Disease (GVHD): Practice Essentials, Background, Pathophysiology
ICARIS 2012 : The 11th International Conference on Artificial Immune Systems
Graft versus Host Disease: From Basic Pathogenic Principles to DNA Damage Response and Cellular Senescence
Home - Professor Liz Simpson
Retroviral transfer of human CD20 as a suicide gene for adoptive T-cell therapy | Haematologica
Kent HAYGLASS - Google Scholar
Department of Microbiology and Immunology | Department of Microbiology and Immunology
JCI Insight - Hematopoietic stem cell-derived Tregs are essential for maintaining favorable B cell lymphopoiesis following...
Embryonic stem cell-derived tissues are… | Oxford Martin School
Joseph H. Antin, MD - DF/HCC
APC Rat Anti-Mouse CD314
Acute Graft-Versus-Host Disease: Diagnostic Criteria & Prevention
The emerging multifunctional roles of ERAP1, ERAP2 and IRAP between antigen processing and renin-angiotensin system modulation
Home
Home
Human UTY(KDM6C) is a male-specific Nϵ-methyl lysyl demethylase<...
TRIM17 and TRIM28 antagonistically regulate the ubiquitination and anti-apoptotic activity of BCL2A1<...
Strategies to Reduce Relapse after Allogeneic Hematopoietic Cell Transplantation in Acute Myeloid Leukemia, Current Hematologic...
Cyclical changes in susceptibility of a myeloma tumor (LPC-1) to immune destruction. I. Changes in reactivity with cytotoxic T...
Roni Nowarski, Ph.D. | Harvard Catalyst Profiles | Harvard Catalyst
CD1-MR1 EMBO workshop: Beyond MHC-restricted lymphocytes, Oxford September 2019. - CAMS Oxford Institute
Синтез олигонуклеотидов (праймеров), цитирование
Transmaternal cell flow leads to antigen-experienced cord blood | Blood | American Society of Hematology
Pesquisa | Biblioteca Virtual em Saúde - BRASIL
Human leukocy6
- Risk factors for development of acute graft-versus-host disease depend upon the type of graft you're using-whether it's from an HLA [human leukocyte antigen]-matched sibling versus an HLA-matched unrelated donor, or if you're using a partially matched donor. (targetedonc.com)
- Long-term engraftment of allogeneic cells necessitates eluding immune-mediated rejection, which is currently achieved by matching for human leukocyte antigen (HLA) expression, immunosuppression, and/or delivery of donor-derived cells to sanctuary sites. (ashpublications.org)
- The human leukocyte antigen (HLA) system is fundamental to transplant biology. (mhmedical.com)
- The graft usually comes from a human leukocyte antigen (HLA)-matched donor and contains hematopoietic cells as well as immune cells, including T lymphocytes. (gvhdhub.com)
- We conducted a meta-analysis of four independent European SLE case collections for associations between SLE sub-phenotypes and MHC single-nucleotide polymorphism genotypes, human leukocyte antigen (HLA) alleles and variant HLA amino acids. (cdc.gov)
- 13 Our study substantially expands this work by not only analysing imputed classical human leukocyte antigen (HLA) alleles, but also examining variant HLA amino-acid positions in conjunction with single-nucleotide polymorphism (SNP) genotypes across the extended MHC region (chromosome 6: 26-34 Mb). (cdc.gov)
Receptors4
- However, there is death by apoptosis of thymocytes that do not interact with MHC molecules or have high-affinity receptors for self MHC plus self antigen a process referred to as negative selection. (wikipedia.org)
- The genetic transfer of T-cell receptors (TCRs) directed toward target antigens into T lymphocytes has been used to generate antitumor T cells efficiently without the need for the in vitro induction and expansion of T cells with cognate specificity. (fujita-hu.ac.jp)
- These data implicate that T cells with high-affinity antigen receptors reduce the ability to lyse targets with low-density peptide/MHC complexes (∼100 per cell), while they could respond at cytokine production level. (fujita-hu.ac.jp)
- Besides the secretion of pro-inflammatory cytokines (TNF-alpha, IL-1beta, and IL-6), the increased expression of receptor repertoire (pattern recognition receptors, PRR) on APCs, mostly macrophages and dendritic cells, occurs as a result of the release of endogenous and exogenous antigens (damage-associated molecular patterns, DAMPs, and pathogen-associated molecular patterns, PAMPs). (hindawi.com)
Specialized antigen-prese2
- class II are expressed on specialized antigen-presenting cells (APCs), such as macrophages, dendritic cells, and B cells. (mhmedical.com)
- Dendritic cells (DC) are specialized antigen-presenting cells. (ox.ac.uk)
Lymphocytes3
- Although graft or bone marrow rejection can have detrimental effects, there are immunotherapy benefits when cytotoxic T lymphocytes are specific for a self antigen and can target antigens expressed selectively on leukemic cells in order to destroy these tumor cells referred to as graft-versus- leukemia effect (GVL). (wikipedia.org)
- Cytotoxic T lymphocytes were determined as the cellular effectors of GVHD, and the key role of antigen-presenting cells (APCs) in T-lymphocyte activation was established during the following years [ 11 , 12 ]. (hindawi.com)
- Although human CD20 has previously been described as functional selection marker and suicide gene after retroviral transfer to T lymphocytes, 9 , 10 the specificities of these T cells were unknown, and therefore a potential effect of CD20 on antigen-specific T-cell functions could not be investigated. (haematologica.org)
GVHD6
- The recipient developed GVHD despite having a HLA- matched genes at the Major Histocompatibility locus. (wikipedia.org)
- Some of these antigens are ubiquitously expressed in nucleated male cells, and the presence of these antigens has been associated with a greater risk of developing GVHD allogeneic stem cell transplantation for a HLA matched gene when there's a male recipient and female donor. (wikipedia.org)
- The histocompatibility differences between the donor and the recipient, the presence of donor's immunocompetent cells, and the inability of the recipient to reject these cells were defined as the basic pathogenic prerequisites for GVHD development by Billingham in 1966 [ 10 ]. (hindawi.com)
- Donor T cells may also induce GvHD due to recognition of allo-antigens on non-malignant tissues of the patient. (haematologica.org)
- Minor histocompatibility antigen differences likely account for GVHD in HLA-identical sibling stem cell transplants. (unboundmedicine.com)
- However, even in a fully HLA matched HCT, GVHD still occurs due to donor T cells directed against minor histocompatibility antigens (MiHAs), polymorphic peptides displayed on host HLA molecules. (mhmedical.com)
Cells28
- This contrasts with MHC class II molecules's antigens which are peptides derived from phagocytosis/endocytosis and molecular degradation of non-self entities' proteins, usually by antigen-presenting cells. (wikipedia.org)
- MiHA antigens are either ubiquitously expressed in most tissue like skin and intestines or restrictively expressed in the immune cells. (wikipedia.org)
- The lack of recognition of a T cell to this self antigen is the reason why allogeneic stem cell transplantation for an HLA matched gene or a developing fetus's MiHAs during pregnancy may not be recognized by T cells and marked as foreign leading to an immune response. (wikipedia.org)
- Alternatively, T cells have been gene-modified with a TCR-like antibody or chimeric antigen receptor (CAR). (fujita-hu.ac.jp)
- 100-fold higher antigen density to exert cytotoxicity compared with the cognate CTL clone, they could produce inflammatory cytokines against cells expressing HLA-A2 and HA-1 H transgenes. (fujita-hu.ac.jp)
- The roles of antigen-specificity, responsiveness to TGFβ and APC subsets in tumour-induced expansion of regulatory T cells. (imperial.ac.uk)
- The use of CD20 as suicide gene was investigated in CMV specific T cells and in T cells genetically modified with an antigen specific T-cell receptor. (haematologica.org)
- 1 , 2 The anti-tumor effect of DLI is mediated by donor T cells recognizing allo-antigens on the malignant cells of the recipient. (haematologica.org)
- T-cell receptor (TCR) gene transfer is an attractive strategy for rapid in vitro generation of high numbers of antigen specific T cells. (haematologica.org)
- 4 In addition, TCRs for minor histocompatibility antigens, including HA-1 and HA-2, have been transferred to donor-derived virus-specific T cells to treat patients with hematologic malignancies after allogeneic stem cell transplantation. (haematologica.org)
- Requirement for B cells in T cell priming to minor histocompatibility antigens and development of graft-versus-host disease. (google.ca)
- Here, we show that even expression of minor histocompatibility (mH) antigens is sufficient to provoke acute rejection of tissues differentiated from ES cells. (ox.ac.uk)
- This propensity for tolerance could be attributed to the paucity of professional antigen-presenting cells and the expression of transforming growth factor (TGF)-?2. (ox.ac.uk)
- Therefore, the immune cells that are passively transferred in the stem cell graft are more primed against these minor histocompatibility antigens that are known to be associated with the development of acute graft-versus-host disease. (targetedonc.com)
- or actively by prior immunization of the recipient with graft antigens which evoke specific antibodies and form antigen-antibody complexes which bind to the antigen receptor sites of the T-cells and block their cytotoxic activity. (lookformedical.com)
- In situ dissection of the graft-versus-host activities of cytotoxic T cells for minor histocompatibility antigens. (alcyomics.com)
- The implication of these results would be that myeloma-specific T cell subfamilies might be positively selected from the donor inoculum and infused to myeloma patients post ASCT, to afford separation of allo- from tumor-reactive T cells without the prior need to define specific target antigens. (biomedcentral.com)
- A key role of the immune system is to detect tumor antigens, engage T cells, and eradicate the tumor. (elevate.bio)
- TCRs are molecules found on surface of T cells that can recognize tumor antigens that are degraded to small protein fragments inside tumor cells. (elevate.bio)
- Unlike CAR T cells that recognize only surface antigens, TCRs can recognize small protein fragments derived from intracellular and surface antigens offering a more diverse way to attack tumors. (elevate.bio)
- These small protein fragments show up on the tumor cell surface, with another protein called major histocompatibility complex (MHC), that are recognized by the TCRs and consequently signal the body's immune system to respond to fight off and kill the tumor cells. (elevate.bio)
- Adoptive T cell therapy can be applied to tackling relapse of leukemia post hematopoietic stem cell transplant (HSCT) by targeting the antigens expressed only by the patient's native cells, and not by the cells from the stem cell transplant donor. (elevate.bio)
- The target of TSC-100 is the minor histocompatibility antigen HA-1, which is a lineage-specific antigen found on blood cells. (tscan.com)
- La primera publicación de Galadriel Mirkwood fue titulada " In a fully H-2 incompatible chimera, T cells of donor origin can respond to minor histocompatibility antigens in association with either donor or host H-2 type "² ( Matzinger & Mirkwood , 1978), aunque a diferencia de Hetherington, Matizinger fue baneada de la revista "Journal of Experimental Medicine" debido a su inusual coautora. (nabbublog.cl)
- Galadriel Mirkwood's first publication was titled " In a fully H-2 incompatible chimera, T cells of donor origin can respond to minor histocompatibility antigens in association with either donor or host H-2 type " ( Matzinger & Mirkwood , 1978), although unlike Hetherington, Matizinger was banned from the journal "Journal of Experimental Medicine" due to its unusual co-author. (nabbublog.cl)
- In phase I, chemotherapy or radiotherapy as part of transplant conditioning causes host tissue damage and release of inflammatory cytokines such as TNF-α, IL-1, and IL-6, with resulting priming of host antigen-presenting cells (APCs). (mhmedical.com)
- DC can acquire and process antigens in the periphery before maturing and migrating to secondary lymphoid tissues where they present the antigens and deliver co-stimulatory signals to T cells. (ox.ac.uk)
- Mucosal-associated invariant T (MAIT) cells are an innate-like T-cell population restricted by the non-polymorphic, major histocompatibility complex class I-related protein 1, MR1. (ox.ac.uk)
Self antigen2
- The recognition of a mature T cell to this self antigen should not induce an immune response. (wikipedia.org)
- Absence of a costimulatory signal results in T-cell anergy, which is a key mechanism of peripheral immune tolerance to self-antigen in normal immunoregulation. (mhmedical.com)
MiHAs2
- Minor histocompatibility antigens (MiHAs) are diverse, short segments of proteins and are referred to as peptides. (wikipedia.org)
- The MiHAs encoded by the Y chromosome are known as HY antigens. (wikipedia.org)
Graft2
- To test for linked suppression, animals were transplanted with a second graft-bearing tolerated and third party antigens. (ox.ac.uk)
- Splenocytes from these and control tolerant animals when transferred into partially immunocompromised Fas mutant or control recipients, induced antigen-specific suppression of graft rejection. (ox.ac.uk)
TCRs1
- Concurrent with its use for shared antigens, BlueSphere is deploying TCXpress™ and NEOXpress™, a proprietary patient-specific neoantigen discovery platform, to develop its TCX-201 Program, which aims to identify TCRs reactive against patient-specific neoantigens. (bluespherebio.com)
Mice5
- We show that immunization of HLA-A2 transgenic mice with tetramerized recombinant HLA-A2 incorporating HA-1 H minor histocompatibility antigen (mHag) peptides and β2- microglobulin (HA-1 H/HLA-A2) generate highly specific antibodies. (fujita-hu.ac.jp)
- Mice lacking C1q or C3 show accelerated rejection of minor H disparate skin grafts and resistance to induction of tolerance. (imperial.ac.uk)
- METHODS: Tolerance to transplanted skin and bone marrow, mismatched for multiple minor histocompatibility antigens, was induced in Fas mutant and control mice using anti-CD4 and anti-CD8 monoclonal antibodies. (ox.ac.uk)
- RESULTS: Monoclonal antibody therapy rendered Fas mutant mice tolerant of minor disparate skin and bone marrow. (ox.ac.uk)
- Additionally, tolerant Fas mutant mice accepted grafts bearing tolerated and third party antigens. (ox.ac.uk)
Antibodies1
- The major focus of the Department of Immunology is on Translational Immunology and its spectrum of basic research covers T cell biology, antibodies, antigen presentation and innate immunity. (immunology-tuebingen.de)
Immunology1
- Our identification of the first non-human primate-specific minor histocompatibility antigen now published at Frontiers in Immunology. (wisc.edu)
Peptides2
- Minor histocompatibility antigen (also known as MiHA) are peptides presented on the cellular surface of donated organs that are known to give an immunological response in some organ transplants. (wikipedia.org)
- These peptides are normally around 9-12 amino acids in length and are bound to both the major histocompatibility complex (MHC) class I and class II proteins. (wikipedia.org)
Genes3
- Even when a transplant donor and recipient are identical with respect to their major histocompatibility complex genes, the amino acid differences in minor proteins can cause the grafted tissue to be slowly rejected. (wikipedia.org)
- H-Y antigens are encoded by genes on the Y chromosome. (wikipedia.org)
- 12 - 15 These studies focused mainly on major histocompatibility complex (MHC) class II genes, and found evidence that class II alleles such as HLA-DRB1*03:01 are associated with auto-antibody production. (cdc.gov)
Allogeneic5
- Kelly Olsen defended her doctoral dissertation, Shared Minor Histocompatibility Antigen Discovery and Targeting in the Context of Allogeneic Hematopoietic Cell Transplant for Hematologic Malignancies. (unc.edu)
- An immune response with both cellular and humoral components, directed against an allogeneic transplant, whose tissue antigens are not compatible with those of the recipient. (lookformedical.com)
- The prognosis for leukemia patients who've relapsed or who have residual disease following allogeneic hematopoietic stem cell transplantation is often poor, but we believe that by targeting the minor H antigen, HA-1, through a novel T cell immunotherapy, we can potentially treat and prevent subsequent relapse," said Elizabeth Krakow, M.D., MSc. (elevate.bio)
- H60 is a minor histocompatibility antigen for which the specific CD8 T-cell response dominates during alloresponse after MHC-matched allogeneic transplantation. (molcells.org)
- BSB-1001, targeting the minor histocompatibility antigen-1 (HA-1) and part of BlueSphere's TCX-101 Program, is the first TCR-T cell therapy candidate generated using TCXpress and is in development for the treatment of acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL) and myeloid dysplastic syndrome (MDS) in conjunction with allogeneic hematopoietic stem cell transplantation (alloSCT). (bluespherebio.com)
Recognition1
- These sanctions were, however, seen as weak by anti for major and minor histocompatibility antigen recognition. (iboard.my)
Molecular1
- These antigens include organic dusts containing bacteria, fungi,4 animal or plant proteins, or low-molecular-weight chemicals. (cdc.gov)
Tumor2
- About 12 days after LPC-1, a myeloma tumor, was transplanted it became resistant to lysis by allogenic CTL (anti-H-2(d)) and by CTL directed to trinitrophenyl groups or minor histocompatibility antigens. (elsevierpure.com)
- However, the immune response to tumor antigens varies and is often insufficient to prevent tumor growth and relapse. (elevate.bio)
Identical2
- Transplantation between genetically identical individuals, i.e., members of the same species with identical histocompatibility antigens, such as monozygotic twins, members of the same inbred strain, or members of a hybrid population produced by crossing certain inbred strains. (lookformedical.com)
- Donor and recipient pairs should be of identical ABO blood group, and in addition should be matched as closely as possible for HISTOCOMPATIBILITY ANTIGENS in order to minimize the likelihood of allograft rejection. (lookformedical.com)
Rejection1
- They cause problems of rejection less frequently than those of the major histocompatibility complex (MHC). (wikipedia.org)
Alleles1
- Both HLA class I and II alleles have been found to present these antigens. (wikipedia.org)
Genetically1
- The former are genetically determined by the major histocompatibility complex. (bvsalud.org)
Transplant1
- Identification of the major histocompatibility antigens of transplant DONORS and potential recipients, usually by serological tests. (lookformedical.com)
Presentation2
- These observations suggest that its role in antigen presentation is not essential. (uniroma1.it)
- The HLAs are highly polymorphic proteins that have a key role in antigen presentation and immunoregulation. (mhmedical.com)
Cellular2
- The response was CD4 help-depen-dent, demonstrating the potency of H60H as a cellular antigen. (molcells.org)
- The response induced by the H60H cellular antigen was comparable to that induced by H60 in its peak magnitude and overall immune kinetics. (molcells.org)
Specific3
- Twenty-three female UCB samples were collected from healthy mothers and analyzed for minor histocompatibility Ag HY-specific responses. (ashpublications.org)
- It may be nonspecific as in the administration of immunosuppressive agents (drugs or radiation) or by lymphocyte depletion or may be specific as in desensitization or the simultaneous administration of antigen and immunosuppressive drugs. (lookformedical.com)
- TSC-101 is targeted to the lineage-specific blood cell antigen HA-2, which is a novel target for cell therapy. (tscan.com)
Major and m1
- A group of antigens that includes both the major and minor histocompatibility antigens. (bvsalud.org)
Proteins1
- Minor histocompatibility antigens are due to normal proteins that are in themselves polymorphic in a given population. (wikipedia.org)
Role2
- The Endoplasmic Reticulum Aminopeptidase 1 and 2 (ERAP1 and ERAP2) and Insulin Regulated Aminopeptidase (IRAP) are three M1 zinc metalloproteases whose role in antigen processing is the refining of peptidome either in the Endoplasmic reticulum (ERAP1 and ERAP2), or in the endosomes (IRAP). (uniroma1.it)
- Although genetic variation within the major histocompatibility complex (MHC) is associated with SLE, its role in the development of clinical manifestations and autoantibody production is not well defined. (cdc.gov)
Ulcers3
- Clinically, the number and size of the ulcers are the two main criteria used to divide ulcers into three forms: minor, major, and herpetiform. (medscape.com)
- In contrast, complex aphthosis has a severe clinical course, with an almost continuous presence of minor or major ulcers. (medscape.com)
- Microvascular disease may also impair skin healing, so that even minor breaks in skin integrity can develop into deeper ulcers and easily become infected, particularly in the lower extremities. (msdmanuals.com)
Form1
- In general, there are few lesions of the minor or herpetiform form. (medscape.com)
Small1
- Minor aphthous ulcer: Small superficial oval erosions with yellow pseudomembrane and an erythematous border are evident on the labial aspect of the left lower lip. (medscape.com)
Blood1
- Typical isoantigens are the BLOOD GROUP ANTIGENS. (lookformedical.com)