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)
Phenotype
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Models, Biological
Molecular 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.
Base Sequence
Cloning, Molecular
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Amino Acid Sequence
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.
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.
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.
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.
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.
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.
Genes, T-Cell Receptor beta
DNA, Complementary
DNA
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Transfection
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
B-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.
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.
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.
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.
Cell Division
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.
Gene Rearrangement, beta-Chain T-Cell Antigen Receptor
Cells, Cultured
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.
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.
Interleukin-2
A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.
Cell Line, Transformed
Eukaryotic cell line obtained in a quiescent or stationary phase which undergoes conversion to a state of unregulated growth in culture, resembling an in vitro tumor. It occurs spontaneously or through interaction with viruses, oncogenes, radiation, or drugs/chemicals.
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.
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 Cooperation
T-cell enhancement of the B-cell response to thymic-dependent antigens.
Sequence Analysis, DNA
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Cytotoxicity, 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.
Blotting, Southern
A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
HLA-DR Serological Subtypes
HLA-DR antigen subtypes that have been classified according to their affinity to specific ANTIBODIES. The DNA sequence analyses of HLA-DR ALPHA-CHAINS and HLA-DR BETA-CHAINS has for the most part revealed the specific alleles that are responsible for each serological subtype.
Nucleic Acid Hybridization
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
Mice, Inbred BALB C
Complementarity Determining Regions
Three regions (CDR1; CDR2 and CDR3) of amino acid sequence in the IMMUNOGLOBULIN VARIABLE REGION that are highly divergent. Together the CDRs from the light and heavy immunoglobulin chains form a surface that is complementary to the antigen. These regions are also present in other members of the immunoglobulin superfamily, for example, T-cell receptors (RECEPTORS, ANTIGEN, T-CELL).
Sequence Homology, Nucleic Acid
Major Histocompatibility Complex
The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.
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, Surface
Genetic Vectors
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
Cell Differentiation
Genes
Myelin Basic Protein
An abundant cytosolic protein that plays a critical role in the structure of multilamellar myelin. Myelin basic protein binds to the cytosolic sides of myelin cell membranes and causes a tight adhesion between opposing cell membranes.
Peptide Fragments
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.
Mutation
Gene Expression
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
Immunoglobulin Variable Region
That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.
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.
Immunodominant Epitopes
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.
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.
HLA-DR2 Antigen
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.
Autoantigens
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).
Recombinant Proteins
Proteins prepared by recombinant DNA technology.
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)
Sequence Homology, Amino Acid
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.
Antigens, 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.
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.
Retroviridae
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
Cross Reactions
Mice, Inbred C57BL
Inbred C57BL mice are a strain of laboratory mice that have been produced by many generations of brother-sister matings, resulting in a high degree of genetic uniformity and homozygosity, making them widely used for biomedical research, including studies on genetics, immunology, cancer, and neuroscience.
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.
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.
Transcription, Genetic
Antigens, Neoplasm
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.
Hybridomas
Cells artificially created by fusion of activated lymphocytes with neoplastic cells. The resulting hybrid cells are cloned and produce pure MONOCLONAL ANTIBODIES or T-cell products, identical to those produced by the immunologically competent parent cell.
Plasmids
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
Hybrid Cells
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.
Blotting, Northern
Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
DNA Primers
Peptides
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Mice, Inbred DBA
HLA-DRB4 Chains
Isoantigens
Antigens that exist in alternative (allelic) forms in a single species. When an isoantigen is encountered by species members who lack it, an immune response is induced. Typical isoantigens are the BLOOD GROUP ANTIGENS.
Chromosome Mapping
Any method used for determining the location of and relative distances between genes on a chromosome.
HLA Antigens
Cytotoxicity Tests, Immunologic
Genes, MHC Class II
Genetic loci in the vertebrate major histocompatibility complex that encode polymorphic products which control the immune response to specific antigens. The genes are found in the HLA-D region in humans and in the I region in mice.
DNA, Recombinant
Cell Transformation, Viral
An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.
Receptor-CD3 Complex, Antigen, T-Cell
Molecule composed of the non-covalent association of the T-cell antigen receptor (RECEPTORS, ANTIGEN, T-CELL) with the CD3 complex (ANTIGENS, CD3). This association is required for the surface expression and function of both components. The molecule consists of up to seven chains: either the alpha/beta or gamma/delta chains of the T-cell receptor, and four or five chains in the CD3 complex.
Herpesvirus 4, Human
Gene Expression Regulation
Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor
DNA Restriction Enzymes
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.
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)
HLA-A2 Antigen
Cricetinae
Chromosomes, Artificial, Bacterial
Virus Replication
HLA-DP beta-Chains
Transmembrane proteins that form the beta subunits of the HLA-DP antigens.
Cell Separation
Cell Transformation, Neoplastic
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.
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.
Sequence Alignment
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Mice, Inbred A
Genomic Library
A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).
Peptide Library
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).
Neoplasm Proteins
Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.
Mice, Inbred NOD
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).
T-Cell Antigen Receptor Specificity
The property of the T-CELL RECEPTOR which enables it to react with some antigens and not others. The specificity is derived from the structure of the receptor's variable region which has the ability to recognize certain antigens in conjunction with the MAJOR HISTOCOMPATIBILITY COMPLEX molecule.
HLA-D Antigens
Human immune-response or Class II antigens found mainly, but not exclusively, on B-lymphocytes and produced from genes of the HLA-D locus. They are extremely polymorphic families of glycopeptides, each consisting of two chains, alpha and beta. This group of antigens includes the -DR, -DQ and -DP designations, of which HLA-DR is most studied; some of these glycoproteins are associated with certain diseases, possibly of immune etiology.
Immunoglobulin Heavy Chains
Epitope Mapping
Methods used for studying the interactions of antibodies with specific regions of protein antigens. Important applications of epitope mapping are found within the area of immunochemistry.
Genes, Immunoglobulin
Genes encoding the different subunits of the IMMUNOGLOBULINS, for example the IMMUNOGLOBULIN LIGHT CHAIN GENES and the IMMUNOGLOBULIN HEAVY CHAIN GENES. The heavy and light immunoglobulin genes are present as gene segments in the germline cells. The completed genes are created when the segments are shuffled and assembled (B-LYMPHOCYTE GENE REARRANGEMENT) during B-LYMPHOCYTE maturation. The gene segments of the human light and heavy chain germline genes are symbolized V (variable), J (joining) and C (constant). The heavy chain germline genes have an additional segment D (diversity).
Receptors, Immunologic
Antibody Specificity
MART-1 Antigen
Mice, Transgenic
Repetitive Sequences, Nucleic Acid
Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).
H-2 Antigens
The major group of transplantation antigens in the mouse.
Molecular Mimicry
HLA-DR3 Antigen
Gene Rearrangement, T-Lymphocyte
Cell Line, Tumor
A cell line derived from cultured tumor cells.
HLA-DR4 Antigen
Autoimmunity
Process whereby the immune system reacts against the body's own tissues. Autoimmunity may produce or be caused by AUTOIMMUNE DISEASES.
Membrane Proteins
Mice, Inbred CBA
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.
Clonal Anergy
Functional inactivation of T- or B-lymphocytes rendering them incapable of eliciting an immune response to antigen. This occurs through different mechanisms in the two kinds of lymphocytes and can contribute to SELF TOLERANCE.
Lymphokines
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.
Arsanilic Acid
Cosmids
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.
HLA-DP Antigens
A group of the D-related HLA antigens (human) found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.
Species Specificity
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Mice, Inbred C3H
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.
Babesia bovis
Multigene Family
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
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.
Stem Cells
p-Azobenzenearsonate
DNA Probes
Species- or subspecies-specific DNA (including COMPLEMENTARY DNA; conserved genes, whole chromosomes, or whole genomes) used in hybridization studies in order to identify microorganisms, to measure DNA-DNA homologies, to group subspecies, etc. The DNA probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the DNA probe include the radioisotope labels 32P and 125I and the chemical label biotin. The use of DNA probes provides a specific, sensitive, rapid, and inexpensive replacement for cell culture techniques for diagnosing infections.
RNA
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Immunoglobulin Idiotypes
Unique genetically-controlled determinants present on ANTIBODIES whose specificity is limited to a single group of proteins (e.g., another antibody molecule or an individual myeloma protein). The idiotype appears to represent the antigenicity of the antigen-binding site of the antibody and to be genetically codetermined with it. The idiotypic determinants have been precisely located to the IMMUNOGLOBULIN VARIABLE REGION of both immunoglobin polypeptide chains.
Virus Integration
Gene Rearrangement, B-Lymphocyte
Ordered rearrangement of B-lymphocyte variable gene regions coding for the IMMUNOGLOBULIN CHAINS, thereby contributing to antibody diversity. It occurs during the differentiation of the IMMATURE B-LYMPHOCYTES.
Desmoglein 3
Cell Survival
Oligonucleotide Probes
Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the probe include the radioisotope labels 32P and 125I and the chemical label biotin.
Electrophoresis, Gel, Pulsed-Field
Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.
Recombinant Fusion Proteins
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)
Escherichia coli
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
NK Cell Lectin-Like Receptor Subfamily D
Macrophage-Activating Factors
Factors secreted by stimulated lymphocytes that prime macrophages to become nonspecifically cytotoxic to tumors. They also modulate the expression of macrophage cell surface Ia antigens. One MAF is INTERFERON-GAMMA. Other factors antigenically distinct from IFN-gamma have also been identified.
Gene Rearrangement, B-Lymphocyte, Heavy Chain
Ordered rearrangement of B-lymphocyte variable gene regions of the IMMUNOGLOBULIN HEAVY CHAINS, thereby contributing to antibody diversity. It occurs during the first stage of differentiation of the IMMATURE B-LYMPHOCYTES.
HLA-DR1 Antigen
HLA-B Antigens
Class I human histocompatibility (HLA) surface antigens encoded by more than 30 detectable alleles on locus B of the HLA complex, the most polymorphic of all the HLA specificities. Several of these antigens (e.g., HLA-B27, -B7, -B8) are strongly associated with predisposition to rheumatoid and other autoimmune disorders. Like other class I HLA determinants, they are involved in the cellular immune reactivity of cytolytic T lymphocytes.
Proviruses
Duplex DNA sequences in eukaryotic chromosomes, corresponding to the genome of a virus, that are transmitted from one cell generation to the next without causing lysis of the host. Proviruses are often associated with neoplastic cell transformation and are key features of retrovirus biology.
Promoter Regions, Genetic
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
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.
Immunoglobulin G
Multiple Sclerosis
An autoimmune disorder mainly affecting young adults and characterized by destruction of myelin in the central nervous system. Pathologic findings include multiple sharply demarcated areas of demyelination throughout the white matter of the central nervous system. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia, and bladder dysfunction. The usual pattern is one of recurrent attacks followed by partial recovery (see MULTIPLE SCLEROSIS, RELAPSING-REMITTING), but acute fulminating and chronic progressive forms (see MULTIPLE SCLEROSIS, CHRONIC PROGRESSIVE) also occur. (Adams et al., Principles of Neurology, 6th ed, p903)
Autoimmune Diseases
Disorders that are characterized by the production of antibodies that react with host tissues or immune effector cells that are autoreactive to endogenous peptides.
Interleukins
Soluble factors which stimulate growth-related activities of leukocytes as well as other cell types. They enhance cell proliferation and differentiation, DNA synthesis, secretion of other biologically active molecules and responses to immune and inflammatory stimuli.
Mycobacterium leprae
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.
Dose-Response Relationship, Immunologic
Drug Resistance
Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.
HLA-A Antigens
Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of tissue/organ grafts.