Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Lymphocytes: White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Lymph: The interstitial fluid that is in the LYMPHATIC SYSTEM.Antigens, CD3: Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL). The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA).Lymph Node Excision: Surgical excision of one or more lymph nodes. Its most common use is in cancer surgery. (From Dorland, 28th ed, p966)Lymphatic Metastasis: Transfer of a neoplasm from its primary site to lymph nodes or to distant parts of the body by way of the lymphatic system.Antigens, CD8: Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.Sentinel Lymph Node Biopsy: A diagnostic procedure used to determine whether LYMPHATIC METASTASIS has occurred. The sentinel lymph node is the first lymph node to receive drainage from a neoplasm.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Antigens, CD: Differentiation antigens residing on mammalian leukocytes. CD stands for cluster of differentiation, which refers to groups of monoclonal antibodies that show similar reactivity with certain subpopulations of antigens of a particular lineage or differentiation stage. The subpopulations of antigens are also known by the same CD designation.T-Lymphocytes, Cytotoxic: Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.CD4-CD8 Ratio: Ratio of T-LYMPHOCYTES that express the CD4 ANTIGEN to those that express the CD8 ANTIGEN. This value is commonly assessed in the diagnosis and staging of diseases affecting the IMMUNE SYSTEM including HIV INFECTIONS.Spleen: An encapsulated lymphatic organ through which venous blood filters.B-Lymphocytes: Lymphoid cells concerned with humoral immunity. They are short-lived cells resembling bursa-derived lymphocytes of birds in their production of immunoglobulin upon appropriate stimulation.Lymphocyte Count: The number of LYMPHOCYTES per unit volume of BLOOD.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.T-Lymphocyte Subsets: A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.Lymphocyte Subsets: A classification of lymphocytes based on structurally or functionally different populations of cells.CD40 Ligand: A membrane glycoprotein and differentiation antigen expressed on the surface of T-cells that binds to CD40 ANTIGENS on B-LYMPHOCYTES and induces their proliferation. Mutation of the gene for CD40 ligand is a cause of HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 1.Antigens, CD28: Costimulatory T-LYMPHOCYTE receptors that have specificity for CD80 ANTIGEN and CD86 ANTIGEN. Activation of this receptor results in increased T-cell proliferation, cytokine production and promotion of T-cell survival.Antigens, CD40: A member of the tumor necrosis factor receptor superfamily with specificity for CD40 LIGAND. It is found on mature B-LYMPHOCYTES and some EPITHELIAL CELLS, lymphoid DENDRITIC CELLS. Evidence suggests that CD40-dependent activation of B-cells is important for generation of memory B-cells within the germinal centers. Mutations of the gene for CD40 antigen result in HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 3. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Mice, Inbred C57BLCytotoxicity, Immunologic: The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.Interleukin-2: A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.Antigens, CD44: Acidic sulfated integral membrane glycoproteins expressed in several alternatively spliced and variable glycosylated forms on a wide variety of cell types including mature T-cells, B-cells, medullary thymocytes, granulocytes, macrophages, erythrocytes, and fibroblasts. CD44 antigens are the principle cell surface receptors for hyaluronate and this interaction mediates binding of lymphocytes to high endothelial venules. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)Mice, Inbred BALB CAntigens, Differentiation, T-Lymphocyte: Antigens expressed on the cell membrane of T-lymphocytes during differentiation, activation, and normal and neoplastic transformation. Their phenotypic characterization is important in differential diagnosis and studies of thymic ontogeny and T-cell function.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Immunophenotyping: Process of classifying cells of the immune system based on structural and functional differences. The process is commonly used to analyze and sort T-lymphocytes into subsets based on CD antigens by the technique of flow cytometry.Antigens, CD34: Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Thymus Gland: A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.Dendritic Cells: Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).Receptors, Antigen, T-Cell: Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.Lymphocytes, Tumor-Infiltrating: Lymphocytes that show specificity for autologous tumor cells. Ex vivo isolation and culturing of TIL with interleukin-2, followed by reinfusion into the patient, is one form of adoptive immunotherapy of cancer.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Axilla: Area of the human body underneath the SHOULDER JOINT, also known as the armpit or underarm.Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Antigens, Surface: Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.Antigens, CD2: Glycoprotein members of the immunoglobulin superfamily which participate in T-cell adhesion and activation. They are expressed on most peripheral T-lymphocytes, natural killer cells, and thymocytes, and function as co-receptors or accessory molecules in the T-cell receptor complex.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Antigens, CD80: A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CTLA-4 ANTIGEN with high specificity and to CD28 ANTIGEN with low specificity. The interaction of CD80 with CD28 ANTIGEN provides a costimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.T-Lymphocytes, Regulatory: CD4-positive T cells that inhibit immunopathology or autoimmune disease in vivo. They inhibit the immune response by influencing the activity of other cell types. Regulatory T-cells include naturally occurring CD4+CD25+ cells, IL-10 secreting Tr1 cells, and Th3 cells.T-Lymphocytes, Helper-Inducer: Subpopulation of CD4+ lymphocytes that cooperate with other lymphocytes (either T or B) to initiate a variety of immune functions. For example, helper-inducer T-cells cooperate with B-cells to produce antibodies to thymus-dependent antigens and with other subpopulations of T-cells to initiate a variety of cell-mediated immune functions.Clone Cells: A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)Antigens, CD95: A tumor necrosis factor receptor subtype found in a variety of tissues and on activated LYMPHOCYTES. It has specificity for FAS LIGAND and plays a role in regulation of peripheral immune responses and APOPTOSIS. Multiple isoforms of the protein exist due to multiple ALTERNATIVE SPLICING. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.Lymphatic Diseases: Diseases of LYMPH; LYMPH NODES; or LYMPHATIC VESSELS.Antigens, CD38: A bifunctional enzyme that catalyzes the synthesis and HYDROLYSIS of CYCLIC ADP-RIBOSE (cADPR) from NAD+ to ADP-RIBOSE. It is a cell surface molecule which is predominantly expressed on LYMPHOID CELLS and MYELOID CELLS.Mesentery: A layer of the peritoneum which attaches the abdominal viscera to the ABDOMINAL WALL and conveys their blood vessels and nerves.Lymphoid Tissue: Specialized tissues that are components of the lymphatic system. They provide fixed locations within the body where a variety of LYMPHOCYTES can form, mature and multiply. The lymphoid tissues are connected by a network of LYMPHATIC VESSELS.Receptors, Antigen, T-Cell, alpha-beta: T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Antigens, CD14: Glycolipid-anchored membrane glycoproteins expressed on cells of the myelomonocyte lineage including monocytes, macrophages, and some granulocytes. They function as receptors for the complex of lipopolysaccharide (LPS) and LPS-binding protein.Lymphocyte Culture Test, Mixed: Measure of histocompatibility at the HL-A locus. Peripheral blood lymphocytes from two individuals are mixed together in tissue culture for several days. Lymphocytes from incompatible individuals will stimulate each other to proliferate significantly (measured by tritiated thymidine uptake) whereas those from compatible individuals will not. In the one-way MLC test, the lymphocytes from one of the individuals are inactivated (usually by treatment with MITOMYCIN or radiation) thereby allowing only the untreated remaining population of cells to proliferate in response to foreign histocompatibility antigens.Antigens, CD1: Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.Cell SeparationMolecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Phytohemagglutinins: Mucoproteins isolated from the kidney bean (Phaseolus vulgaris); some of them are mitogenic to lymphocytes, others agglutinate all or certain types of erythrocytes or lymphocytes. They are used mainly in the study of immune mechanisms and in cell culture.Antigens, CD19: Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.Antigens, CD5: Glycoproteins expressed on all mature T-cells, thymocytes, and a subset of mature B-cells. Antibodies specific for CD5 can enhance T-cell receptor-mediated T-cell activation. The B-cell-specific molecule CD72 is a natural ligand for CD5. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Tuberculosis, Lymph Node: Infection of the lymph nodes by tuberculosis. Tuberculous infection of the cervical lymph nodes is scrofula.Antigens, CD86: A costimulatory ligand expressed by ANTIGEN-PRESENTING CELLS that binds to CD28 ANTIGEN with high specificity and to CTLA-4 ANTIGEN with low specificity. The interaction of CD86 with CD28 ANTIGEN provides a stimulatory signal to T-LYMPHOCYTES, while its interaction with CTLA-4 ANTIGEN may play a role in inducing PERIPHERAL TOLERANCE.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Antigens, CD45: High-molecular weight glycoproteins uniquely expressed on the surface of LEUKOCYTES and their hemopoietic progenitors. They contain a cytoplasmic protein tyrosine phosphatase activity which plays a role in intracellular signaling from the CELL SURFACE RECEPTORS. The CD45 antigens occur as multiple isoforms that result from alternative mRNA splicing and differential usage of three exons.Leukocyte Count: The number of WHITE BLOOD CELLS per unit volume in venous BLOOD. A differential leukocyte count measures the relative numbers of the different types of white cells.Time Factors: Elements of limited time intervals, contributing to particular results or situations.CD4 Lymphocyte Count: The number of CD4-POSITIVE T-LYMPHOCYTES per unit volume of BLOOD. Determination requires the use of a fluorescence-activated flow cytometer.Antigens, Differentiation: Antigens expressed primarily on the membranes of living cells during sequential stages of maturation and differentiation. As immunologic markers they have high organ and tissue specificity and are useful as probes in studies of normal cell development as well as neoplastic transformation.Cell Movement: The movement of cells from one location to another. Distinguish from CYTOKINESIS which is the process of dividing the CYTOPLASM of a cell.Antigens, CD4: 55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. CD4 antigens are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. CD4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.Concanavalin A: A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.Receptors, Interleukin-2: Receptors present on activated T-LYMPHOCYTES and B-LYMPHOCYTES that are specific for INTERLEUKIN-2 and play an important role in LYMPHOCYTE ACTIVATION. They are heterotrimeric proteins consisting of the INTERLEUKIN-2 RECEPTOR ALPHA SUBUNIT, the INTERLEUKIN-2 RECEPTOR BETA SUBUNIT, and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Immunologic Memory: The altered state of immunologic responsiveness resulting from initial contact with antigen, which enables the individual to produce antibodies more rapidly and in greater quantity in response to secondary antigenic stimulus.Antigens, CD56: The 140 kDa isoform of NCAM (neural cell adhesion molecule) containing a transmembrane domain and short cytoplasmic tail. It is expressed by all lymphocytes mediating non-MHC restricted cytotoxicity and is present on some neural tissues and tumors.Interleukin-4: A soluble factor produced by activated T-LYMPHOCYTES that induces the expression of MHC CLASS II GENES and FC RECEPTORS on B-LYMPHOCYTES and causes their proliferation and differentiation. It also acts on T-lymphocytes, MAST CELLS, and several other hematopoietic lineage cells.Macrophages: The relatively long-lived phagocytic cell of mammalian tissues that are derived from blood MONOCYTES. Main types are PERITONEAL MACROPHAGES; ALVEOLAR MACROPHAGES; HISTIOCYTES; KUPFFER CELLS of the liver; and OSTEOCLASTS. They may further differentiate within chronic inflammatory lesions to EPITHELIOID CELLS or may fuse to form FOREIGN BODY GIANT CELLS or LANGHANS GIANT CELLS. (from The Dictionary of Cell Biology, Lackie and Dow, 3rd ed.)Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Mediastinum: A membrane in the midline of the THORAX of mammals. It separates the lungs between the STERNUM in front and the VERTEBRAL COLUMN behind. It also surrounds the HEART, TRACHEA, ESOPHAGUS, THYMUS, and LYMPH NODES.Killer Cells, Natural: Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.Antigens: Substances that are recognized by the immune system and induce an immune reaction.Histocompatibility Antigens Class II: Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.Cytotoxicity Tests, Immunologic: The demonstration of the cytotoxic effect on a target cell of a lymphocyte, a mediator released by a sensitized lymphocyte, an antibody, or complement.Lymphocyte Depletion: Immunosuppression by reduction of circulating lymphocytes or by T-cell depletion of bone marrow. The former may be accomplished in vivo by thoracic duct drainage or administration of antilymphocyte serum. The latter is performed ex vivo on bone marrow before its transplantation.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.HLA-DR Antigens: A subclass of HLA-D antigens that consist of alpha and beta chains. The inheritance of HLA-DR antigens differs from that of the HLA-DQ ANTIGENS and HLA-DP ANTIGENS.Antigens, CD18: Cell-surface glycoprotein beta-chains that are non-covalently linked to specific alpha-chains of the CD11 family of leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE-ADHESION). A defect in the gene encoding CD18 causes LEUKOCYTE-ADHESION DEFICIENCY SYNDROME.Breast Neoplasms: Tumors or cancer of the human BREAST.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Th1 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete interleukin-2, gamma-interferon, and interleukin-12. Due to their ability to kill antigen-presenting cells and their lymphokine-mediated effector activity, Th1 cells are associated with vigorous delayed-type hypersensitivity reactions.Melanoma: A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)Lymphatic System: A system of organs and tissues that process and transport immune cells and LYMPH.Lymphocyte Transfusion: The transfer of lymphocytes from a donor to a recipient or reinfusion to the donor.Lichenoid Eruptions: Conditions in which there is histological damage to the lower epidermis along with a grouped chronic inflammatory infiltrate in the papillary dermis disturbing the interface between the epidermis and dermis. LICHEN PLANUS is the prototype of all lichenoid eruptions. (From Rook et al., Textbook of Dermatology, 4th ed, p398)Antigens, CD43: A sialic acid-rich protein and an integral cell membrane mucin. It plays an important role in activation of T-LYMPHOCYTES.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Antigens, CD20: Unglycosylated phosphoproteins expressed only on B-cells. They are regulators of transmembrane Ca2+ conductance and thought to play a role in B-cell activation and proliferation.Jurkat Cells: A CELL LINE derived from human T-CELL LEUKEMIA and used to determine the mechanism of differential susceptibility to anti-cancer drugs and radiation.Receptors, Lymphocyte Homing: Cell surface glycoproteins on lymphocytes and other leukocytes that mediate adhesion to specialized blood vessels called high endothelial venules. Several different classes of lymphocyte homing receptors have been identified, and they appear to target different surface molecules (addressins) on high endothelial venules in different tissues. The adhesion plays a crucial role in the trafficking of lymphocytes.Epitopes, T-Lymphocyte: Antigenic determinants recognized and bound by the T-cell receptor. Epitopes recognized by the T-cell receptor are often located in the inner, unexposed side of the antigen, and become accessible to the T-cell receptors after proteolytic processing of the antigen.Epitopes: Sites on an antigen that interact with specific antibodies.Sinoatrial Node: The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Antigens, CD30: A member of the tumor necrosis factor receptor superfamily that may play a role in the regulation of NF-KAPPA B and APOPTOSIS. They are found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; NEUTROPHILS; EOSINOPHILS; MAST CELLS and NK CELLS. Overexpression of CD30 antigen in hematopoietic malignancies make the antigen clinically useful as a biological tumor marker. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Antigen Presentation: The process by which antigen is presented to lymphocytes in a form they can recognize. This is performed by antigen presenting cells (APCs). Some antigens require processing before they can be recognized. Antigen processing consists of ingestion and partial digestion of the antigen by the APC, followed by presentation of fragments on the cell surface. (From Rosen et al., Dictionary of Immunology, 1989)Immune Tolerance: The specific failure of a normally responsive individual to make an immune response to a known antigen. It results from previous contact with the antigen by an immunologically immature individual (fetus or neonate) or by an adult exposed to extreme high-dose or low-dose antigen, or by exposure to radiation, antimetabolites, antilymphocytic serum, etc.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Lymphocyte Cooperation: T-cell enhancement of the B-cell response to thymic-dependent antigens.Mice, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.Antigens, CD24: A cell adhesion protein that was originally identified as a heat stable antigen in mice. It is involved in METASTASIS and is highly expressed in many NEOPLASMS.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Adoptive Transfer: Form of passive immunization where previously sensitized immunologic agents (cells or serum) are transferred to non-immune recipients. When transfer of cells is used as a therapy for the treatment of neoplasms, it is called adoptive immunotherapy (IMMUNOTHERAPY, ADOPTIVE).Antigens, CD7: Differentiation antigens expressed on pluripotential hematopoietic cells, most human thymocytes, and a major subset of peripheral blood T-lymphocytes. They have been implicated in integrin-mediated cellular adhesion and as signalling receptors on T-cells.Mitogens: Substances that stimulate mitosis and lymphocyte transformation. They include not only substances associated with LECTINS, but also substances from streptococci (associated with streptolysin S) and from strains of alpha-toxin-producing staphylococci. (Stedman, 25th ed)Neck: The part of a human or animal body connecting the HEAD to the rest of the body.Antigens, CD57: Oligosaccharide antigenic determinants found principally on NK cells and T-cells. Their role in the immune response is poorly understood.Antigen-Presenting Cells: A heterogeneous group of immunocompetent cells that mediate the cellular immune response by processing and presenting antigens to the T-cells. Traditional antigen-presenting cells include MACROPHAGES; DENDRITIC CELLS; LANGERHANS CELLS; and B-LYMPHOCYTES. FOLLICULAR DENDRITIC CELLS are not traditional antigen-presenting cells, but because they hold antigen on their cell surface in the form of IMMUNE COMPLEXES for B-cell recognition they are considered so by some authors.Lymphocyte Function-Associated Antigen-1: An integrin heterodimer widely expressed on cells of hematopoietic origin. CD11A ANTIGEN comprises the alpha chain and the CD18 antigen (ANTIGENS, CD18) the beta chain. Lymphocyte function-associated antigen-1 is a major receptor of T-CELLS; B-CELLS; and GRANULOCYTES. It mediates the leukocyte adhesion reactions underlying cytolytic conjugate formation, helper T-cell interactions, and antibody-dependent killing by NATURAL KILLER CELLS and granulocytes. Intracellular adhesion molecule-1 has been defined as a ligand for lymphocyte function-associated antigen-1.Antigens, CD11: A group of three different alpha chains (CD11a, CD11b, CD11c) that are associated with an invariant CD18 beta chain (ANTIGENS, CD18). The three resulting leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE ADHESION) are LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1; MACROPHAGE-1 ANTIGEN; and ANTIGEN, P150,95.Forkhead Transcription Factors: A subclass of winged helix DNA-binding proteins that share homology with their founding member fork head protein, Drosophila.Leukocytes, Mononuclear: Mature LYMPHOCYTES and MONOCYTES transported by the blood to the body's extravascular space. They are morphologically distinguishable from mature granulocytic leukocytes by their large, non-lobed nuclei and lack of coarse, heavily stained cytoplasmic granules.L-Selectin: Cell adhesion molecule and CD antigen that serves as a homing receptor for lymphocytes to lymph node high endothelial venules.Monocytes: Large, phagocytic mononuclear leukocytes produced in the vertebrate BONE MARROW and released into the BLOOD; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Rosette Formation: The in vitro formation of clusters consisting of a cell (usually a lymphocyte) surrounded by antigenic cells or antigen-bearing particles (usually erythrocytes, which may or may not be coated with antibody or antibody and complement). The rosette-forming cell may be an antibody-forming cell, a memory cell, a T-cell, a cell bearing surface cytophilic antibodies, or a monocyte possessing Fc receptors. Rosette formation can be used to identify specific populations of these cells.Antigens, CD11c: An integrin alpha subunit of approximately 150-kDa molecular weight. It is expressed at high levels on monocytes and combines with CD18 ANTIGEN to form the cell surface receptor INTEGRIN ALPHAXBETA2. The subunit contains a conserved I-domain which is characteristic of several of alpha integrins.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Palatine Tonsil: A round-to-oval mass of lymphoid tissue embedded in the lateral wall of the PHARYNX. There is one on each side of the oropharynx in the fauces between the anterior and posterior pillars of the SOFT PALATE.Antigens, CD9: A subtype of tetraspanin proteins that play a role in cell adhesion, cell motility, and tumor metastasis. CD9 antigens take part in the process of platelet activation and aggregation, the formation of paranodal junctions in neuronal tissue, and the fusion of sperm with egg.Immunization: Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).Antigens, CD11b: A CD antigen that contains a conserved I domain which is involved in ligand binding. When combined with CD18 the two subunits form MACROPHAGE-1 ANTIGEN.Antibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Receptors, CCR7: CCR receptors with specificity for CHEMOKINE CCL19 and CHEMOKINE CCL21. They are expressed at high levels in T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS.Mice, Inbred C3HAdenocarcinoma: A malignant epithelial tumor with a glandular organization.Antigens, CD36: Leukocyte differentiation antigens and major platelet membrane glycoproteins present on MONOCYTES; ENDOTHELIAL CELLS; PLATELETS; and mammary EPITHELIAL CELLS. They play major roles in CELL ADHESION; SIGNAL TRANSDUCTION; and regulation of angiogenesis. CD36 is a receptor for THROMBOSPONDINS and can act as a scavenger receptor that recognizes and transports oxidized LIPOPROTEINS and FATTY ACIDS.Immunoglobulins: Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.Receptors, Antigen, T-Cell, gamma-delta: T-cell receptors composed of CD3-associated gamma and delta polypeptide chains and expressed primarily in CD4-/CD8- T-cells. The receptors appear to be preferentially located in epithelial sites and probably play a role in the recognition of bacterial antigens. The T-cell receptor gamma/delta chains are separate and not related to the gamma and delta chains which are subunits of CD3 (see ANTIGENS, CD3).Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Skin Neoplasms: Tumors or cancer of the SKIN.Stomach Neoplasms: Tumors or cancer of the STOMACH.Carcinoma, Squamous Cell: A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.Mice, Inbred CBAOvalbumin: An albumin obtained from the white of eggs. It is a member of the serpin superfamily.Neoplasm Invasiveness: Ability of neoplasms to infiltrate and actively destroy surrounding tissue.Immunotherapy, Adoptive: Form of adoptive transfer where cells with antitumor activity are transferred to the tumor-bearing host in order to mediate tumor regression. The lymphoid cells commonly used are lymphokine-activated killer (LAK) cells and tumor-infiltrating lymphocytes (TIL). This is usually considered a form of passive immunotherapy. (From DeVita, et al., Cancer, 1993, pp.305-7, 314)Lymphatic Vessels: Tubular vessels that are involved in the transport of LYMPH and LYMPHOCYTES.Cell Adhesion: Adherence of cells to surfaces or to other cells.Peyer's Patches: Lymphoid tissue on the mucosa of the small intestine.Perforin: A calcium-dependent pore-forming protein synthesized in cytolytic LYMPHOCYTES and sequestered in secretory granules. Upon immunological reaction between a cytolytic lymphocyte and a target cell, perforin is released at the plasma membrane and polymerizes into transmembrane tubules (forming pores) which lead to death of a target cell.HLA-A2 Antigen: A specific HLA-A surface antigen subtype. Members of this subtype contain alpha chains that are encoded by the HLA-A*02 allele family.Histocompatibility Antigens Class I: Membrane glycoproteins consisting of an alpha subunit and a BETA 2-MICROGLOBULIN beta subunit. In humans, highly polymorphic genes on CHROMOSOME 6 encode the alpha subunits of class I antigens and play an important role in determining the serological specificity of the surface antigen. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during GRAFT REJECTION and restrict cell-mediated lysis of virus-infected cells.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Lectins: Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.Lymphadenitis: Inflammation of the lymph nodes.Antigens, CD59: Small glycoproteins found on both hematopoietic and non-hematopoietic cells. CD59 restricts the cytolytic activity of homologous complement by binding to C8 and C9 and blocking the assembly of the membrane attack complex. (From Barclay et al., The Leukocyte Antigen FactsBook, 1993, p234)Atrioventricular Node: A small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus. It gives rise to the atrioventricular bundle of the conduction system of the heart.Immunoenzyme Techniques: Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.H-2 Antigens: The major group of transplantation antigens in the mouse.Antigens, CD70: A transmembrane protein belonging to the tumor necrosis factor superfamily that specifically binds to CD27 ANTIGEN. It is found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS where it plays a role in stimulating the proliferation of CD4-POSITIVE T-LYMPHOCYTES and CD8-POSITIVE T-LYMPHOCYTES.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Lymphoma: A general term for various neoplastic diseases of the lymphoid tissue.Antigens, CD47: A ubiquitously expressed membrane glycoprotein. It interacts with a variety of INTEGRINS and mediates responses to EXTRACELLULAR MATRIX PROTEINS.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Receptors, Antigen, B-Cell: IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.Hypersensitivity, Delayed: An increased reactivity to specific antigens mediated not by antibodies but by cells.Chemotaxis, Leukocyte: The movement of leukocytes in response to a chemical concentration gradient or to products formed in an immunologic reaction.Histocompatibility Antigens: A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They determine tissue type for transplantation and cause allograft rejections. The latter are systems of allelic alloantigens that can cause weak transplant rejection.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Antigens, CD46: A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.Coculture Techniques: A technique of culturing mixed cell types in vitro to allow their synergistic or antagonistic interactions, such as on CELL DIFFERENTIATION or APOPTOSIS. Coculture can be of different types of cells, tissues, or organs from normal or disease states.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Receptors, Immunologic: Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.Receptors, Chemokine: Cell surface glycoproteins that bind to chemokines and thus mediate the migration of pro-inflammatory molecules. The receptors are members of the seven-transmembrane G protein-coupled receptor family. Like the CHEMOKINES themselves, the receptors can be divided into at least three structural branches: CR, CCR, and CXCR, according to variations in a shared cysteine motif.Carcinoma: A malignant neoplasm made up of epithelial cells tending to infiltrate the surrounding tissues and give rise to metastases. It is a histological type of neoplasm but is often wrongly used as a synonym for "cancer." (From Dorland, 27th ed)Th2 Cells: Subset of helper-inducer T-lymphocytes which synthesize and secrete the interleukins IL-4, IL-5, IL-6, and IL-10. These cytokines influence B-cell development and antibody production as well as augmenting humoral responses.Mice, SCID: Mice homozygous for the mutant autosomal recessive gene "scid" which is located on the centromeric end of chromosome 16. These mice lack mature, functional lymphocytes and are thus highly susceptible to lethal opportunistic infections if not chronically treated with antibiotics. The lack of B- and T-cell immunity resembles severe combined immunodeficiency (SCID) syndrome in human infants. SCID mice are useful as animal models since they are receptive to implantation of a human immune system producing SCID-human (SCID-hu) hematochimeric mice.Fas Ligand Protein: A transmembrane protein belonging to the tumor necrosis factor superfamily that was originally discovered on cells of the lymphoid-myeloid lineage, including activated T-LYMPHOCYTES and NATURAL KILLER CELLS. It plays an important role in immune homeostasis and cell-mediated toxicity by binding to the FAS RECEPTOR and triggering APOPTOSIS.Antigens, CD137: A member of the tumor necrosis factor receptor superfamily that is specific for 4-1BB LIGAND. It is found in a variety of immune cell types including activated T-LYMPHOCYTES; NATURAL KILLER CELLS; and DENDRITIC CELLS. Activation of the receptor on T-LYMPHOCYTES plays a role in their expansion, production of cytokines and survival. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.Pore Forming Cytotoxic Proteins: Proteins secreted from an organism which form membrane-spanning pores in target cells to destroy them. This is in contrast to PORINS and MEMBRANE TRANSPORT PROTEINS that function within the synthesizing organism and COMPLEMENT immune proteins. These pore forming cytotoxic proteins are a form of primitive cellular defense which are also found in human LYMPHOCYTES.Antigens, CD58: Glycoproteins with a wide distribution on hematopoietic and non-hematopoietic cells and strongly expressed on macrophages. CD58 mediates cell adhesion by binding to CD2; (ANTIGENS, CD2); and this enhances antigen-specific T-cell activation.Bone Marrow: The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.Lectins, C-Type: A class of animal lectins that bind to carbohydrate in a calcium-dependent manner. They share a common carbohydrate-binding domain that is structurally distinct from other classes of lectins.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Dose-Response Relationship, Immunologic: A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.Mice, Inbred DBA
  • Both experimental subcutaneous inoculation with MMTV and milk-borne infection produce dramatic increases in the numbers of DCs in the draining lymph nodes and Peyer's patches, respectively ( 8 , 24 ). (asm.org)
  • The intraepithelial lymphocytes (IELs) that reside within the epithelium of the intestine form one of the main branches of the immune system. (nih.gov)
  • An increase in the CD4 cell count is viewed as a beneficial consequence of highly active antiretroviral therapies (HAART), and as an indicator of immune recovery. (lww.com)
  • These data support the notion that PCV2-positive pigs might have an impaired immune response. (asm.org)
  • CD4 counts used to be the only way to understand how HIV was affecting your immune system. (positivewomen.org.au)
  • Significant associations were found among tumor cell PD-L1 expression, the presence of intratumoral immune cell infiltrates, and PD-1 receptor expression by tumor-infiltrating lymphocytes, suggesting that PD-L1 reflects an immune-reactive milieu. (aacrjournals.org)
  • When immune response is activated, PDCs can be recruited into lymph nodes, tonsils, spleen, and mucosa-associated lymphoid tissue. (thefreelibrary.com)
  • A CD4 cell is a type of white blood cell that is especially important to the immune system. (thebody.com)
  • CLP RAG lymph node restimulation assays exhibited SEA-specific increases in the TH2 cytokines IL-4 (Fig. 6B), IL-5 (Fig. 6C) and IL-13 (Fig. 6E), along with the TH2/immunosuppressive cytokine IL-10 (Fig. 6D). (nih.gov)
  • While sham RAG lymph node cultures also exhibited SEA-specific production of both IL-17 and IFN-γ, the levels of these cytokines were below the levels observed for TH2 cytokines from the same cultures. (nih.gov)
  • The ability of T lymphocytes to produce cytokines in response to pathogenic organisms is crucial in inducing and maintaining effective innate as well as acquired immunity. (asm.org)
  • L-DCs stimulated strong proliferative responses, induced secretion of inflammatory cytokines including interferon-gamma, and induced FoxP3-positive lymphocytes to divide. (gu.se)
  • Gossypol suppresses leukemic cell differentiation in response to tumor-promoting phorboids and decreases the expression of interleukin 2 (IL-2) and interferon  (IFN-) in activated human T lymphocytes . (termedia.pl)
  • Brain computed tomography scans of the patient depicted a massive sylvian infarction while an abdominal computed tomography scan revealed multiple enlarged abdominal lymph nodes and a retroperitoneal mass adjacent to the left psoas muscle. (biomedcentral.com)
  • Association between CD4, CD8, and FOXP3 expression and relapse-free interval (RFI). (biomedcentral.com)
  • Partial residuals of the multivariable Cox regression models were plotted against the CD4 ( a ), CD8 ( b ), and FOXP3 ( c ) expression. (biomedcentral.com)
  • Kaplan-Meier curves and adjusted hazard ratios (HRs) of CD4, CD8, and FOXP3 status were calculated in the whole group ( d , e , and f , respectively) and among patients with low-grade tumors ( g , h , and i , respectively). (biomedcentral.com)
  • In particular, CD4+ T lymphocytes can exhibit reduced proliferative capacity and improper cytokine responses following sepsis. (nih.gov)
  • Surprisingly, CLP RAG lymph nodes also exhibited significantly elevated levels of the TH17 cytokine IL-17 (Fig. 6F), as well as levels of the TH1 cytokine IFN-γ (Fig. 6G). (nih.gov)
  • Since intestinal T lymphocytes are localized at functionally distinct sites, including intestinal epithelium and lamina propria, it will be important to examine isolated cell populations for their cytokine responses. (asm.org)
  • This cytokine receptor binds to B-lymphocyte chemoattractant (BLC), and is involved in B-cell migration into B-cell follicles of spleen and Peyer patches. (cancerindex.org)
  • In this study, we report four cases of EBV + T-cell LPDs with unusual immunophentypic and histopathological features including negativity for CD4 and CD8, multiple foci of necrosis, abundant eosinophils inflitration and granuloma, which adds to the understanding of these rare diseases. (scirp.org)
  • Biopsies of these lymph nodes histologically showed eosinophils and granulomas not unlike what Gall and Rappaport previously described in a group of patients with benign lymphadenopathy. (thefreelibrary.com)
  • The phenotype of the inflammatory cell background infiltrate, along with the neoplastic cell morphological and immunophenotypical features, subdivides HL in 2 subgroups: classical and nodular lymphocyte predominant HL. (hindawi.com)
  • Nodular lymphocyte predominant HL (NLPHL) accounts for less than 10% of all HL cases and is considered a distinct clinical entity [ 4 ]. (hindawi.com)
  • Since the intestine harbors a large pool of activated lymphocytes, it is also an important site for early viral dissemination as well as for the initial host-virus interactions. (asm.org)
  • Mathematical models [10- , based on a `prey-predator' equilibrium, predict that a sustained expansion of the CD4 T lymphocytes subset - the `prey' - increases the probability that HIV - the `predator' - spreads. (lww.com)
  • Our laboratory studies the molecular mechanisms that control the migration of lymphocytes into sites of autoimmune-mediated tissue damage, such as pancreatic islets in type 1 diabetes and salivary glands in Sjogren s syndrome. (stanford.edu)
  • In recent years, the role of chemokines in directing the migration of lymphocytes has been well-characterized. (thermofisher.com)
  • The T2-type response is characterized by reduced macrophage and lymphocyte recruitment, pulmonary eosinophilia, leukocyte production of IL-4 and IL-5 but not IFN-γ, and increased serum IgE. (jimmunol.org)
  • The Histological examination showed a number of atypical lymphocytes broadly infiltrating perineurial connective tissue and subperineurium. (biomedcentral.com)
  • The light and dark sides of intestinal intraepithelial lymphocytes. (nih.gov)
  • The 'light side' shows the beneficial roles of natural and induced intraepithelial lymphocytes (IELs) in preserving the epithelium and restoring tissue integrity after injury. (nih.gov)
  • What are features of lymph follicles? (brainscape.com)
  • PURPOSE: This study evaluated the feasibility of acoustic radiation force impulse (ARFI) elastography and characterized the sonographic features of lymph nodes (LNs) with Kikuchi disease in pediatric patients. (bvsalud.org)
  • In patches of early leprosy granulomas may be absent and lymphocytes may be seen infiltrating the epidermis and follicular epithelium and arrector pilorum muscles. (pangaia.cc)
  • We also cover recent findings with respect to the existence of ectopic lymphoid aggregates found in the TME which are termed tertiary lymphoid structures (TLS) and are generally a positive prognostic feature. (frontiersin.org)