Lymphoma: A general term for various neoplastic diseases of the lymphoid tissue.Lymphoma, T-Cell: A group of heterogeneous lymphoid tumors representing malignant transformations of T-lymphocytes.Lymphoma, B-Cell: A group of heterogeneous lymphoid tumors generally expressing one or more B-cell antigens or representing malignant transformations of B-lymphocytes.Lymphoma, Non-Hodgkin: Any of a group of malignant tumors of lymphoid tissue that differ from HODGKIN DISEASE, being more heterogeneous with respect to malignant cell lineage, clinical course, prognosis, and therapy. The only common feature among these tumors is the absence of giant REED-STERNBERG CELLS, a characteristic of Hodgkin's disease.Lymphoma, Large B-Cell, Diffuse: Malignant lymphoma composed of large B lymphoid cells whose nuclear size can exceed normal macrophage nuclei, or more than twice the size of a normal lymphocyte. The pattern is predominantly diffuse. Most of these lymphomas represent the malignant counterpart of B-lymphocytes at midstage in the process of differentiation.Lymphoma, Follicular: Malignant lymphoma in which the lymphomatous cells are clustered into identifiable nodules within the LYMPH NODES. The nodules resemble to some extent the GERMINAL CENTER of lymph node follicles and most likely represent neoplastic proliferation of lymph node-derived follicular center B-LYMPHOCYTES.Burkitt Lymphoma: A form of undifferentiated malignant LYMPHOMA usually found in central Africa, but also reported in other parts of the world. It is commonly manifested as a large osteolytic lesion in the jaw or as an abdominal mass. B-cell antigens are expressed on the immature cells that make up the tumor in virtually all cases of Burkitt lymphoma. The Epstein-Barr virus (HERPESVIRUS 4, HUMAN) has been isolated from Burkitt lymphoma cases in Africa and it is implicated as the causative agent in these cases; however, most non-African cases are EBV-negative.Lymphoma, T-Cell, Peripheral: A group of malignant lymphomas thought to derive from peripheral T-lymphocytes in lymph nodes and other nonlymphoid sites. They include a broad spectrum of lymphocyte morphology, but in all instances express T-cell markers admixed with epithelioid histiocytes, plasma cells, and eosinophils. Although markedly similar to large-cell immunoblastic lymphoma (LYMPHOMA, LARGE-CELL, IMMUNOBLASTIC), this group's unique features warrant separate treatment.Lymphoma, T-Cell, Cutaneous: A group of lymphomas exhibiting clonal expansion of malignant T-lymphocytes arrested at varying stages of differentiation as well as malignant infiltration of the skin. MYCOSIS FUNGOIDES; SEZARY SYNDROME; LYMPHOMATOID PAPULOSIS; and PRIMARY CUTANEOUS ANAPLASTIC LARGE CELL LYMPHOMA are the best characterized of these disorders.Lymphoma, B-Cell, Marginal Zone: Extranodal lymphoma of lymphoid tissue associated with mucosa that is in contact with exogenous antigens. Many of the sites of these lymphomas, such as the stomach, salivary gland, and thyroid, are normally devoid of lymphoid tissue. They acquire mucosa-associated lymphoid tissue (MALT) type as a result of an immunologically mediated disorder.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.Lymphoma, Mantle-Cell: A form of non-Hodgkin lymphoma having a usually diffuse pattern with both small and medium lymphocytes and small cleaved cells. It accounts for about 5% of adult non-Hodgkin lymphomas in the United States and Europe. The majority of mantle-cell lymphomas are associated with a t(11;14) translocation resulting in overexpression of the CYCLIN D1 gene (GENES, BCL-1).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.Lymphoma, Large-Cell, Anaplastic: A systemic, large-cell, non-Hodgkin, malignant lymphoma characterized by cells with pleomorphic appearance and expressing the CD30 ANTIGEN. These so-called "hallmark" cells have lobulated and indented nuclei. This lymphoma is often mistaken for metastatic carcinoma and MALIGNANT HISTIOCYTOSIS.Lymphoma, AIDS-Related: B-cell lymphoid tumors that occur in association with AIDS. Patients often present with an advanced stage of disease and highly malignant subtypes including BURKITT LYMPHOMA; IMMUNOBLASTIC LARGE-CELL LYMPHOMA; PRIMARY EFFUSION LYMPHOMA; and DIFFUSE, LARGE B-CELL, LYMPHOMA. The tumors are often disseminated in unusual extranodal sites and chromosomal abnormalities are frequently present. It is likely that polyclonal B-cell lymphoproliferation in AIDS is a complex result of EBV infection, HIV antigenic stimulation, and T-cell-dependent HIV activation.Peripheral Nerves: The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. Peripheral nerves contain non-neuronal cells and connective tissue as well as axons. The connective tissue layers include, from the outside to the inside, the epineurium, the perineurium, and the endoneurium.Leukemia-Lymphoma, Adult T-Cell: Aggressive T-Cell malignancy with adult onset, caused by HUMAN T-LYMPHOTROPIC VIRUS 1. It is endemic in Japan, the Caribbean basin, Southeastern United States, Hawaii, and parts of Central and South America and sub-Saharan Africa.Hodgkin Disease: A malignant disease characterized by progressive enlargement of the lymph nodes, spleen, and general lymphoid tissue. In the classical variant, giant usually multinucleate Hodgkin's and REED-STERNBERG CELLS are present; in the nodular lymphocyte predominant variant, lymphocytic and histiocytic cells are seen.Leukemia, T-Cell: A malignant disease of the T-LYMPHOCYTES in the bone marrow, thymus, and/or blood.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.Lymphoma, Large-Cell, Immunoblastic: Malignant lymphoma characterized by the presence of immunoblasts with uniformly round-to-oval nuclei, one or more prominent nucleoli, and abundant cytoplasm. This class may be subdivided into plasmacytoid and clear-cell types based on cytoplasmic characteristics. A third category, pleomorphous, may be analogous to some of the peripheral T-cell lymphomas (LYMPHOMA, T-CELL, PERIPHERAL) recorded in both the United States and Japan.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.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.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.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.Vincristine: An antitumor alkaloid isolated from VINCA ROSEA. (Merck, 11th ed.)Peripheral Nervous System: The nervous system outside of the brain and spinal cord. The peripheral nervous system has autonomic and somatic divisions. The autonomic nervous system includes the enteric, parasympathetic, and sympathetic subdivisions. The somatic nervous system includes the cranial and spinal nerves and their ganglia and the peripheral sensory receptors.Peripheral Nervous System Diseases: Diseases of the peripheral nerves external to the brain and spinal cord, which includes diseases of the nerve roots, ganglia, plexi, autonomic nerves, sensory nerves, and motor nerves.Antibodies, Monoclonal: Antibodies produced by a single clone of cells.Lymphoma, Extranodal NK-T-Cell: An extranodal neoplasm, usually possessing an NK-cell phenotype and associated with EPSTEIN-BARR VIRUS. These lymphomas exhibit a broad morphologic spectrum, frequent necrosis, angioinvasion, and most commonly present in the midfacial region, but also in other extranodal sites.Antibodies, Monoclonal, Murine-Derived: Antibodies obtained from a single clone of cells grown in mice or rats.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.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).Prednisone: A synthetic anti-inflammatory glucocorticoid derived from CORTISONE. It is biologically inert and converted to PREDNISOLONE in the liver.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.Lymph Nodes: They are oval or bean shaped bodies (1 - 30 mm in diameter) located along the lymphatic system.Translocation, Genetic: A type of chromosome aberration characterized by CHROMOSOME BREAKAGE and transfer of the broken-off portion to another location, often to a different chromosome.Cyclophosphamide: Precursor of an alkylating nitrogen mustard antineoplastic and immunosuppressive agent that must be activated in the LIVER to form the active aldophosphamide. It has been used in the treatment of LYMPHOMA and LEUKEMIA. Its side effect, ALOPECIA, has been used for defleecing sheep. Cyclophosphamide may also cause sterility, birth defects, mutations, and cancer.Peripheral Vascular Diseases: Pathological processes involving any one of the BLOOD VESSELS in the vasculature outside the HEART.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.Herpesvirus 4, Human: The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.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.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.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.Mice, Inbred C57BLImmunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Antineoplastic Combined Chemotherapy Protocols: The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.Chromosomes, Human, Pair 14: A specific pair of GROUP D CHROMOSOMES of the human chromosome classification.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.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)Mycosis Fungoides: A chronic, malignant T-cell lymphoma of the skin. In the late stages, the LYMPH NODES and viscera are affected.Doxorubicin: Antineoplastic antibiotic obtained from Streptomyces peucetius. It is a hydroxy derivative of DAUNORUBICIN.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.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).Interleukin-2: A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.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.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Gene Rearrangement: The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.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.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.Human T-lymphotropic virus 1: A strain of PRIMATE T-LYMPHOTROPIC VIRUS 1 isolated from mature T4 cells in patients with T-lymphoproliferation malignancies. It causes adult T-cell leukemia (LEUKEMIA-LYMPHOMA, T-CELL, ACUTE, HTLV-I-ASSOCIATED), T-cell lymphoma (LYMPHOMA, T-CELL), and is involved in mycosis fungoides, SEZARY SYNDROME and tropical spastic paraparesis (PARAPARESIS, TROPICAL SPASTIC).Nose Neoplasms: Tumors or cancer of the NOSE.Thymus Neoplasms: Tumors or cancer of the THYMUS GLAND.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.Spleen: An encapsulated lymphatic organ through which venous blood filters.Skin Neoplasms: Tumors or cancer of the SKIN.Leukemia: A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemias were originally termed acute or chronic based on life expectancy but now are classified according to cellular maturity. Acute leukemias consist of predominately immature cells; chronic leukemias are composed of more mature cells. (From The Merck Manual, 2006)Chromosomes, Human, Pair 18: A specific pair of GROUP E CHROMOSOMES of the human chromosome classification.Mice, Inbred BALB CGene Rearrangement, gamma-Chain T-Cell Antigen Receptor: Ordered rearrangement of T-cell variable gene regions coding for the gamma-chain of antigen receptors.Peripheral Nerve Injuries: Injuries to the PERIPHERAL NERVES.Gene Rearrangement, T-Lymphocyte: Ordered rearrangement of T-cell variable gene regions coding for the antigen receptors.Epstein-Barr Virus Infections: Infection with human herpesvirus 4 (HERPESVIRUS 4, HUMAN); which may facilitate the development of various lymphoproliferative disorders. These include BURKITT LYMPHOMA (African type), INFECTIOUS MONONUCLEOSIS, and oral hairy leukoplakia (LEUKOPLAKIA, HAIRY).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.Peripheral Arterial Disease: Lack of perfusion in the EXTREMITIES resulting from atherosclerosis. It is characterized by INTERMITTENT CLAUDICATION, and an ANKLE BRACHIAL INDEX of 0.9 or less.Transplantation, Autologous: Transplantation of an individual's own tissue from one site to another site.Gene Rearrangement, beta-Chain T-Cell Antigen Receptor: Ordered rearrangement of T-cell variable gene regions coding for the beta-chain of antigen receptors.Reed-Sternberg Cells: Large cells, usually multinucleate, whose presence is a common histologic characteristic of classical HODGKIN DISEASE.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.Lymphoproliferative Disorders: Disorders characterized by proliferation of lymphoid tissue, general or unspecified.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.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.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.Enteropathy-Associated T-Cell Lymphoma: A primary peripheral T-cell lymphoma in the gastrointestinal tract, most often in the jejunum, associated with a history of CELIAC DISEASE or other gastrointestinal diseases.Leukemia, Lymphocytic, Chronic, B-Cell: A chronic leukemia characterized by abnormal B-lymphocytes and often generalized lymphadenopathy. In patients presenting predominately with blood and bone marrow involvement it is called chronic lymphocytic leukemia (CLL); in those predominately with enlarged lymph nodes it is called small lymphocytic lymphoma. These terms represent spectrums of the same disease.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.Proto-Oncogene Proteins c-bcl-6: A DNA-binding protein that represses GENETIC TRANSCRIPTION of target genes by recruiting HISTONE DEACETYLASES. Aberrant Blc-6 expression is associated with certain types of human B-CELL LYMPHOMA.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.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.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.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.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.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.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Combined Modality Therapy: The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.Pseudolymphoma: A group of disorders having a benign course but exhibiting clinical and histological features suggestive of malignant lymphoma. Pseudolymphoma is characterized by a benign infiltration of lymphoid cells or histiocytes which microscopically resembles a malignant lymphoma. (From Dorland, 28th ed & Stedman, 26th ed)Cell Line, Tumor: A cell line derived from cultured tumor cells.Central Nervous System Neoplasms: Benign and malignant neoplastic processes that arise from or secondarily involve the brain, spinal cord, or meninges.Remission Induction: Therapeutic act or process that initiates a response to a complete or partial remission level.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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.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.Cell Proliferation: All of the processes involved in increasing CELL NUMBER including CELL DIVISION.Immunoglobulin Heavy Chains: The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.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.Hematopoietic Stem Cell Transplantation: Transfer of HEMATOPOIETIC STEM CELLS from BONE MARROW or BLOOD between individuals within the same species (TRANSPLANTATION, HOMOLOGOUS) or transfer within the same individual (TRANSPLANTATION, AUTOLOGOUS). Hematopoietic stem cell transplantation has been used as an alternative to BONE MARROW TRANSPLANTATION in the treatment of a variety of neoplasms.Eye Neoplasms: Tumors or cancer of the EYE.Biopsy: Removal and pathologic examination of specimens in the form of small pieces of tissue from the living body.DNA, Neoplasm: DNA present in neoplastic tissue.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.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.Leukemia, Prolymphocytic, T-Cell: A lymphoid leukemia characterized by a profound LYMPHOCYTOSIS with or without LYMPHADENOPATHY, hepatosplenomegaly, frequently rapid progression, and short survival. It was formerly called T-cell chronic lymphocytic leukemia.Survival Analysis: A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.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.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Leukemia, Lymphoid: Leukemia associated with HYPERPLASIA of the lymphoid tissues and increased numbers of circulating malignant LYMPHOCYTES and lymphoblasts.Survival Rate: The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.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.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.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.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.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).Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.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).Genes, T-Cell Receptor beta: DNA sequences encoding the beta chain of the T-cell receptor. The genomic organization of the TcR beta genes is essentially the same in all species and is similar to the organization of Ig genes.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.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Immunotherapy: Manipulation of the host's immune system in treatment of disease. It includes both active and passive immunization as well as immunosuppressive therapy to prevent graft rejection.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.Lymphocyte Count: The number of LYMPHOCYTES per unit volume of BLOOD.In Situ Hybridization, Fluorescence: A type of IN SITU HYBRIDIZATION in which target sequences are stained with fluorescent dye so their location and size can be determined using fluorescence microscopy. This staining is sufficiently distinct that the hybridization signal can be seen both in metaphase spreads and in interphase nuclei.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.Disease-Free Survival: Period after successful treatment in which there is no appearance of the symptoms or effects of the disease.Genes, T-Cell Receptor gamma: DNA sequences encoding the gamma chain of the T-cell receptor. The human gamma-chain locus is organized similarly to the TcR beta-chain locus.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.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.Epitopes: Sites on an antigen that interact with specific antibodies.Germinal Center: The activated center of a lymphoid follicle in secondary lymphoid tissue where B-LYMPHOCYTES are stimulated by antigens and helper T cells (T-LYMPHOCYTES, HELPER-INDUCER) are stimulated to generate memory cells.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.Etoposide: A semisynthetic derivative of PODOPHYLLOTOXIN that exhibits antitumor activity. Etoposide inhibits DNA synthesis by forming a complex with topoisomerase II and DNA. This complex induces breaks in double stranded DNA and prevents repair by topoisomerase II binding. Accumulated breaks in DNA prevent entry into the mitotic phase of cell division, and lead to cell death. Etoposide acts primarily in the G2 and S phases of the cell cycle.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)Gene Expression Regulation, Neoplastic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in neoplastic tissue.Leukemia, B-Cell: A malignant disease of the B-LYMPHOCYTES in the bone marrow and/or blood.Proto-Oncogene Proteins c-bcl-2: Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.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.Recurrence: The return of a sign, symptom, or disease after a remission.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.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.Peripheral Blood Stem Cell Transplantation: Transplantation of stem cells collected from the peripheral blood. It is a less invasive alternative to direct marrow harvesting of hematopoietic stem cells. Enrichment of stem cells in peripheral blood can be achieved by inducing mobilization of stem cells from the BONE MARROW.Genes, T-Cell Receptor: DNA sequences, in cells of the T-lymphocyte lineage, that code for T-cell receptors. The TcR genes are formed by somatic rearrangement (see GENE REARRANGEMENT, T-LYMPHOCYTE and its children) of germline gene segments, and resemble Ig genes in their mechanisms of diversity generation and expression.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.Bleomycin: A complex of related glycopeptide antibiotics from Streptomyces verticillus consisting of bleomycin A2 and B2. It inhibits DNA metabolism and is used as an antineoplastic, especially for solid tumors.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.Transplantation, Homologous: Transplantation between individuals of the same species. Usually refers to genetically disparate individuals in contradistinction to isogeneic transplantation for genetically identical individuals.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Gene Products, tax: Transcriptional trans-acting proteins of the promoter elements found in the long terminal repeats (LTR) of HUMAN T-LYMPHOTROPIC VIRUS 1 and HUMAN T-LYMPHOTROPIC VIRUS 2. The tax (trans-activator x; x is undefined) proteins act by binding to enhancer elements in the LTR.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.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.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, 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.Cell SeparationMembrane Glycoproteins: Glycoproteins found on the membrane or surface of 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.Proto-Oncogene Proteins: Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.Bone Marrow Transplantation: The transference of BONE MARROW from one human or animal to another for a variety of purposes including HEMATOPOIETIC STEM CELL TRANSPLANTATION or MESENCHYMAL STEM CELL TRANSPLANTATION.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.Genes, bcl-2: The B-cell leukemia/lymphoma-2 genes, responsible for blocking apoptosis in normal cells, and associated with follicular lymphoma when overexpressed. Overexpression results from the t(14;18) translocation. The human c-bcl-2 gene is located at 18q24 on the long arm of chromosome 18.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Genes, myc: Family of retrovirus-associated DNA sequences (myc) originally isolated from an avian myelocytomatosis virus. The proto-oncogene myc (c-myc) codes for a nuclear protein which is involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Truncation of the first exon, which appears to regulate c-myc expression, is crucial for tumorigenicity. The human c-myc gene is located at 8q24 on the long arm of chromosome 8.HTLV-I InfectionsReceptors, 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.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Sciatic Nerve: A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.Intestinal Neoplasms: Tumors or cancer of the INTESTINES.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.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.Blood Cells: The cells found in the body fluid circulating throughout the CARDIOVASCULAR SYSTEM.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.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.Chromosome Aberrations: Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.Mediastinal Neoplasms: Tumors or cancer of the MEDIASTINUM.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.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.Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Lymphatic Diseases: Diseases of LYMPH; LYMPH NODES; or LYMPHATIC VESSELS.Mice, Inbred AKRGene 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.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.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Neprilysin: Enzyme that is a major constituent of kidney brush-border membranes and is also present to a lesser degree in the brain and other tissues. It preferentially catalyzes cleavage at the amino group of hydrophobic residues of the B-chain of insulin as well as opioid peptides and other biologically active peptides. The enzyme is inhibited primarily by EDTA, phosphoramidon, and thiorphan and is reactivated by zinc. Neprilysin is identical to common acute lymphoblastic leukemia antigen (CALLA Antigen), an important marker in the diagnosis of human acute lymphocytic leukemia. There is no relationship with CALLA PLANT.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.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.Antigens, Viral: Substances elaborated by viruses that have antigenic activity.