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NLM AIDSLINE
CLONAL NATURE OF THE IMMUNE RESPONSE
Scott DW; Univ. of Rochester Cancer Center and Sch. of Medicine and;
March 30, 1990
Immunol Ser; 43:127-43 1989. Unique Identifier : AIDSLINE ICDB/90657860

Vertebrates have evolved an immune system consisting of both specific and nonspecific defense barriers, which interface with one another to protect the integrity of the organism in a hostile environment. Once potentially pathogenic agents pass through the first lines of defense (skin and mucosal tissues), they interact with both phagocytic cells and lymphocytes, which cooperate to produce humoral or cellular immunity. The biology of clonal selection, clonal growth of T cells, clonal growth of B cells, and disease relevance (AIDS) are discussed, including: Burnet-Jerne clonal selection theory; evidence for one-cell:one-specificity; development of the repertoire; recirculation and recruitment; physiologic changes in lymphoid tissues; antigen recognition by T cells; interleukins and T-cell growth; the anti-mu model; antigen and B-cell subsets; B-cell lymphomas and autocrine growth; and differentiation of B cells and isotype switching. The immune system develops its capacity to respond to different antigens at different times in life, culminating in a diverse and immunocompetent repertoire before the individual is sexually mature. Specific lymphocytes circulate until they encounter an antigen for which they have an affinity. They then remove themselves from the circulation and begin the process known as the specific immune response. Although the exact biochemical mechanisms for the receipt of immunologic signals leading to gene transcription and RNA splicing are unclear, the system eventually condenses into three interacting entities: a T cell, a B cell, and an antigen. The affinity of these cells for antigen through different kinds of molecular receptors and for each other, through major histocompatibility complex interaction and a variety of lymphokines, promotes the clonal expansion of individual cells and the manifestation of an immune response. This ultimately leads to amplification and the inflammation mechanism culminating in the removal of pathogenic organisms. In AIDS, the CD4 helper T cells harbor the human immunodeficiency virus (HIV), putting the system at enormous risk for destruction from within. The CD4 molecule may be the anchor to which HIV attaches itself. (40 Refs)

Acquired Immunodeficiency Syndrome/IMMUNOLOGY Animal *Antibody Formation Antigen-Presenting Cells/IMMUNOLOGY Antigenic Variation Antigens/IMMUNOLOGY B-Lymphocytes/*IMMUNOLOGY Clone Cells/IMMUNOLOGY Human *Immunity, Cellular Interleukin-4/IMMUNOLOGY Lymphoid Tissue/IMMUNOLOGY/PHYSIOLOGY Lymphokines/IMMUNOLOGY Lymphoma/IMMUNOLOGY Major Histocompatibility Complex T-Lymphocytes/*IMMUNOLOGY Tumor Cells, Cultured/IMMUNOLOGY JOURNAL ARTICLE REVIEW REVIEW, TUTORIAL

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