title: Regulation of lymphocyte production in the bone marrow. I. Turnover of small lymphocytes in mice depleted of B lymphocytes by treatment with anti-IgM antibodies.
abstract: To examine the concept that the genesis of lymphocytes in the bone marrow may be regulated by homeostatic feedback signals from peripheral B lymphocytes or their products, lymphocyte production was measured in mice selectively depleted of B lymphocytes by repeated administration of anti-IgM antibodies from birth. The turnover of small lymphocytes was quantitated radioautographically after DNA labeling by continuous infusion of 3H-thymidine. In the femoral marrow of anti-IgM-treated mice, the number of small lymphocytes was reduced and their turnover time was shorter than in control mice, presumably reflecting the premature elimination from the marrow of maturing cells about to express surface IgM. The absolute number of small lymphocytes being produced per femur in unit time, however, was identical in anti-IgM-treated and control mice. Lymphocyte production in the thymus was also unaffected by anti-IgM suppression whereas in the spleen the turnover of small lymphocytes was reduced due to the lack of young immigrant B lymphocytes from the bone marrow. The results demonstrate that the normal large-scale production of lymphocytes in mouse bone marrow is independent of the magnitude of the peripheral pool of B lymphocytes or the level of circulating immunoglobulins, suggesting the process is not subject to feedback control. Some implications for the genesis and diversity of primary B lymphocytes are discussed.
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000008:administration & dosage; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology / Q000378:metabolism; D001854:Bone Marrow Cells; D005260:Female; D006410:Hematopoiesis; D006706:Homeostasis; D007075:Immunoglobulin M / Q000276:immunology; D008212:Lymphocyte Depletion; D008214:Lymphocytes / Q000145:classification / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000378:metabolism
chemical_list: D000888:Antibodies, Anti-Idiotypic; D007075:Immunoglobulin M