Regulation of pre-B cell proliferation in bone marrow: immunofluorescence stathmokinetic studies of cytoplasmic p chain-bearing cells in anti-IgM-treated mice, hematologically deficient mutant mice and mice given sheep red blood cells
✍ Scribed by Davine Opstelten; Dennis G. Osmond
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 770 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0014-2980
No coin nor oath required. For personal study only.
✦ Synopsis
Department of Anatomy, McGill cytoplasmic p chain-bearing cells in anti-IgM-treated mice, hematologically deficient mutant mice and mice
University, Montreal given sheep red blood cells*
To identify factors influencing the in vivo proliferate activity of bone marrow pre-B cells, the metaphase-blocking drug, vincristine sulfate, was injected into (a) mice depleted of B lymphocytes by treatment with anti-mouse IgM antibodies from birth;
(b) hematologically deficient W W and Sl/Sld mutants, and (c) mice injected with a foreign agent, sheep red blood cells (SRBC). Subsequently, a quantitative measure of pre-B cell proliferation was provided by examining marrow cells by immunofluorescence labeling for the absolute number of pre-B cells, identified by the presence of cytoplasmic p chains (cp) without surface p (sp), which had been arrested in metaphase. In anti-IgM-treated mice, some changes were observed in the size of the large pre-B cell population and in the incidence of mitotic cells after vincristine administration, but the overall production rate of pre-B cells did not differ from that in controls given normal rabbit serum. Pre-B cell kinetics in W W and S1/Sld mice also generally resembled those in homozygous controls. In contrast, after SRBC injection, there was an increase in the rate at which large pre-B cells entered mitosis. Thus, the proliferation of cp'sp-bone marrow pre-B cells shows no evidence of feedback control from the mature B lymphocyte pool, as indicated by lack of stimulation of pre-B cell production in anti-IgM-treated mice, and is independent of the hemopoietic defects of W W or Sl/Sld mutants. On the other hand, the increased bone marrow pre-B cell proliferation after SRBC injection demonstrates that the magnitude of B cell genesis in the bone marrow can be influenced by extrinsic agents and thus may be influenced by environmental stimuli.