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THE CELLULAR BASIS OF IMMUNOLOGICAL RESPONSES

1969; Elsevier BV; Volume: 294; Issue: 7616 Linguagem: Inglês

10.1016/s0140-6736(69)92712-3

1474-547X

I.M. Roitt, G Torrigiani, Melvyn F. Greaves, Jonathan Brostoff, J. H. L. Playfair,

T-cell and B-cell Immunology

Abstract Summary The evidence for the existence of distinct populations of thymic-dependent T - lymphocytes and thymic - independent (bursa - equivalent) B-lymphocytes is reviewed. Both populations contain antigen-sensitive cells, probably with specific antibody on their surface. B-lymphocytes can differentiate, proliferate, and mature into plasma-cells which synthesise humoral antibody. On contact with antigen (which may have to be macrophage-processed), the T-lymphocytes transform into large blast-cells and divide both in vivo and in tissue-culture. These T-lymphoblasts, which do not have demonstrable intracellular immunoglobulin, subserve many functions: ( a ) They divide further to form an expanded population of primed antigen-sensitive cells which provide immunological memory because of their long life-span. ( b ) They are " killer " cells which are cytotoxic for graft target-cells. ( c ) They release a number of soluble factors which increase vascular permeability, are mitogenic for other lymphocytes, and activate macrophages, &c. These characteristics taken together with ( b ) form the basis for the phenomena of cell-mediated (delayed) hypersensitivity and cellular immunity. ( d ) They may cooperate during the immune response to certain (" thymus-dependent ") antigens by stimulating the antigen-sensitive B-lymphocyte. The cooperative function of T-lymphoblasts would account for the relationship often observed between delayed hypersensitivity and humoral-antibody formation, and for the occurrence of allergen-induced blastcell transformation of lymphocytes from allergic patients with anaphylactic - type hypersensitivity. Lymphoproliferative disorders, primary immunological deficiency, and autoimmune diseases can also be analysed in terms of T-lymphocyte and B-lymphocyte populations.