| Co-Investigator(Kenkyū-buntansha) |
SUGIURA Kikuya SCHOOL.MED.KANSAI MEDICAL UNIVERSITY RESEARCH ASSOCIATE, 医学部, 助手 (30171143)
HISHA Hiroko SCHOOL.MED.KANSAI MEDICAL UNIVERSITY RESEARCH ASSOCIATE, 医学部, 助手 (90151422)
TOKI Junko SCHOOL.MED.KANSAI MEDICAL UNIVERSITY RESEARCH ASSOCIATE, 医学部, 助手 (40077681)
YASUMIZU Ryoji SCHOOL.MED.KANSAI MEDICAL UNIVERSITY ASSISTANT PROFESSOR, 医学部, 講師 (00142753)
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| Budget Amount *help |
¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
We characterize B cell progenitors in the thymus. Though mature thymic B cells are sIg^+, B220^+, but CD43^-, B cell progenitors in the thymus were found to be sIg^-, B220^<med>, and CD43^+. Most progenitors showed rearranged Ig D-J and V-D-J patterns when DNA from sorted B cell progenitors was amplified by PCR,blotted and probed. When B cell progenitors were purified from the thymus and injected intrathymically into Igh-allotype disparate recipients, B cells bearing donor-type Igh6 were detected in the thymus but not in the periphery. Thymic B cells generated from these progenitors were CD5^+ cells, though there was a broad range of expression of CD5 molecules. Furthermore, B cells purified from thymus that had been inoculated with B cell progenitors were able to differentiate into antibody-forming cells under the influence of CD40 ligand plus IL-10, and secreted IgM with donor Igh6-allotype. When thymic progenitor B cells were intravenously injected into scid mice, thymic progenitor B cells can differentiate to mature B cells, and the percentage of CD5^+ B cells detected in the thymus after iv. injection was significantly higher than those in the spleen and lymph nodes. These findings indicate the possibility that the surface phenotye of B cells is influenced by the microenvironment. To clarify the in vitro condition that supports the differentiation of thymic progenitor B cells, stroma cells. In the presence of IL-7, thymic stroma cells, but not stroma cells from the bone marrow nor thymic cell lines, could support the differentiation of thymic progenitor B cells.
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