[T- and B-lymphocytes. Distribution in the body, their functional and morphological characteristics and significance].

In a survey of the literature special attention is given to the history of development of concepts concerning the existence in the immunocompetent system of the lymphoid tissue of higher vertebrals and man of two independent to some extent populations of lymphocytes: one dependent on the thymus gland and therefore called T-lymphocytes population, implementing cellular reactions of immunity; and the other, similar one, dependent on Fabricius' bursa in birds and called B-lymphocytes, producing antibodies circulaing in the blood. Functional-morphological characteristics of T-and B-lymphocytes, their distribution in the peripheral organs of the lymphoid system and in the blood are given. The role of T-and B-lymphocytes in rejection of allotransplants and in the reaction of a transplant against the host development of reactions of hypersensitivity of the delayed and immediate types is discussed. The need for a further study of participation of T-and B-lymphocytes in pathogenesis of allergic, autoimmune and numerous other diseases that are accompanied by immune disorders, is emphasized.