title: Ontogeny of thymic B cells in normal mice.
abstract: Ontogeny of thymic B cells and their surface characteristics were analyzed using monoclonal antibodies (mAbs) against B220 molecules (CD45, CD45R). A small number of B cells were detected in fetal thymus on Gestation Day 14 (approximately 3.5% of the low-density fraction). Similarly, the percentage of B cells in the low-density fraction was 3.2% on Gestation Day 18, and 3.5% on Day 1 after birth. These were the same level as that of adult mice. CD5+ B cells, which form the major population of thymic B cells, were also found in the fetal life (0.5% on Day 14 and 2.2% on Day 16 in the low-density cells). The percentage of CD5+ B cells in B cell-enriched fraction was about 65% on Day 1 after birth, which is the same level as that in adult mice. These results indicate that a small number of B cells or cells in the B-cell lineage are present in the fetal thymus and also suggest the importance of these thymic B cells in the negative selection of T cells during early developmental stages.
authors.affiliation: Department of Ophthalmology, Kansai Medical University, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nango
authors.forename: M
authors.initials: M
authors.lastname: Inaba
authors.forename: K
authors.initials: K
authors.lastname: Inaba
authors.forename: Y
authors.initials: Y
authors.lastname: Adachi
authors.forename: S
authors.initials: S
authors.lastname: Than
authors.forename: T
authors.initials: T
authors.lastname: Ishida
authors.forename: T
authors.initials: T
authors.lastname: Kumamoto
authors.forename: M
authors.initials: M
authors.lastname: Uyama
authors.forename: S
authors.initials: S
authors.lastname: Ikehara
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000276:immunology; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000166:cytology; D001402:B-Lymphocytes / Q000166:cytology*; D018956:CD5 Antigens; D002454:Cell Differentiation; D005434:Flow Cytometry; D006649:Histocompatibility Antigens / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D017493:Leukocyte Common Antigens; D051379:Mice; D008807:Mice, Inbred BALB C; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D013950:Thymus Gland / Q000166:cytology* / Q000196:embryology
chemical_list: D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000944:Antigens, Differentiation, B-Lymphocyte; D018956:CD5 Antigens; D006649:Histocompatibility Antigens; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell; D017493:Leukocyte Common Antigens