Does the CLL B lymphocyte correspond to expansion of an immature B clone or to expansion of a distinct subpopulation of B cells?
Most CLL cases correspond to proliferation of a B-cell clone characterized by (1) low amounts of SmIg, (2) the presence of receptors for mouse red blood cells, (3) the presence of a 67-kd antigenic determinant recognized by CD5 monoclonal antibodies, also present in normal T cells, (4) the ability of these cells to differentiate in vitro, and (5) the ability at least for some clones to differentiate and secrete immunoglobulins in vivo. The normal counterpart to this B-cell clone corresponds to a small subpopulation of lymphocytes, present at the edge of the germinal center in human lymph nodes. Interestingly, this subpopulation appears to constitute a substantial part of the B-cell population in 20-week-old fetal lymph nodes and spleen. These results have induced most authors to assume that the CLL B lymphocyte corresponds to proliferation of an immature B-cell clone, arrested at an intermediate stage between pre-B cells and mature B cells. However, this hypothesis does not explain the high frequency with which hypogammaglobulinemia and autoimmune hemolytic anemia are found in B CLL. In this work, we discuss the possibility that the CLL B lymphocyte corresponds to proliferation of a B-cell line, whose counterpart in the mouse is the Ly1 B, Lyb5+ subpopulation.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D001323:Autoantibodies / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D007945:Leukemia, Lymphoid / Q000276:immunology*; D008213:Lymphocyte Activation
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D001323:Autoantibodies; D007075:Immunoglobulin M