Thymus processed lymphocytes

DIVEMA is known to act upon different types of immune cells (J 3) such as the antibody producing B cells (bone marrow derived lymphocytes) on T-cells (thymus processed lymphocytes) and on macrophages (cells which phagocytose foreign material). The mechanisms of interaction between polymers and the immune system are very complex. In order to investigate them, many different experimental approaches can be used. 

Immunologically reactive or immunocompetent cells are lymphocytes which, together with granulocytes and erythrocytes, originate from common hemopoietic stem cells (Wu et al. 1967). The sites of primary lymphopoiesis are the bursa of Fabricius (in birds) and the thymus in mammals no bursa has been found but an equivalent organ is inferred (Mitchell and Miller 1968 Perey et al. 1968 Owen and Ritter 1969). Lymphocytes which differentiate within the thymus independent of antigenic influence become thymus-derived or thymus-processed lymphocytes, so-called T-cells. It is now generally accepted that a cooperation between T-cells and bursa-equivalent lymphocytes (B-cells) is necessary for induction of IgM... 

Golstein, P., Wigzell, H., Blomgren, H., Svedmyr, E. A. J. Cells mediating specific in vitro cytotoxicity. II. Probable autonomy of thymus processed lymphocytes (T cells) for the killing of allogeneic target cells. J. exp. Med. 135, 890-906 (1972). 

Rubin, B., Wigzell, H. The immune response against hapten-autologous protein conjugates in the mouse. III. Specificity of cooperating non-thymus-processed (B) and thymus-processed (T) lymphocytes. J. exp. Med. 137, 911-931 (1972). 

Lymphocytes are one of the primary cell types involved in the immune response. There are two general types of lymphocytes, B and T. Both are derived from bone marrow lymphoid stem cells, but T cells go through an additional maturation process in the thymus. Although the morphology of T cells and B cells is similar, the functions of these two types are distinct. After antigen exposure, B cells develop into antibody-producing plasma cells, whereas T cells are divided into functional subtypes that possess distinct cell surface antigens. 

In the process of food tolerance development, the presence of other cell populations have been observed, namely Treg lymphocytes (CD4+ CD25+), Ts CD8, Th3 CD4 CD25, and atypical cells of hepatic origin which may participate in immu-noregulation processes—the so-called double-marked lymphocytes, scarce in the system in order to avoid negative selection in the thymus. 

T-cells T (thymus derived) cell. These white blood cells, known as T lymphocytes, mature in the thymus and have regulatory immune funcdons. As part of the adapdve (cell-mediated) immune system, these cells can recognize andgens processed by andgen-presendng cells in the context of specific receptors. The cell surface protein CDS is a marker for these cells. 

Immature T cells produced in the bone marrow ultimately migrate to the thymus, where they both expand and mature into immunologically competent cells (see Fig. 98 ). A variety of cytokines, including IL-2, IL-4, and lL-7, facilitate lymphopoiesis, whereas others such as transforming growth factor-/ may decelerate this process. T lymphocytes are probably the longest lived hematopoietic cell, as there is experimental evidence that the life span of some is more than 10 years. 

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