Development of VH81X transgene-bearing B cells in fetus and adult: sites for expansion and deletion in conventional and CD5/B1 cells.
The most D-proximal functional VH gene, VH81X, is preferentially expressed in the mouse fetal B cell repertoire; however, it is expressed in few B cells in the adult. To determine when VH81X gene expression affects size and phenotype of particular stages in B cell differentiation, transgenic mice have been developed expressing a germline fetal liver-derived VH81X-mu rearrangement. Comparative analysis of B lymphopoiesis reveals similarities and differences between fetal liver and adult bone marrow which pinpoint developmental stages in mice during which VH81X-expressing B cell progenitors expand or deplete compartment sizes. These include a similar reduction in c-kitR+ and establishment of a predominant CD43low/HSAhigh phenotype within the B220+ CD43+ compartment which is dependent on the association of the transgene with lambda 5. In contrast, the CD43- pre-B and immature B cell compartments are expanded in the fetus but not in the adult. In addition, there are other factors that later disfavor the survival of VH81X-expressing B1 and B2 cells. Thus the failure to detect VH81X-bearing B cells in the adult is the result of a multistep selection process occurring at all stages during B repertoire expansion.
Martin
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F
Department of Microbiology, University of Alabama at Birmingham 35294-3300, USA.
Chen
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Kearney
J F
JF
D000375:Aging / Q000276:immunology*; D000818:Animals; D000831:Animals, Newborn; D015703:Antigens, CD; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D017637:Clonal Deletion / Q000276:immunology*; D005314:Embryonic and Fetal Development / Q000235:genetics / Q000276:immunology*; D005803:Genes, Immunoglobulin; D006825:Hybridomas / Q000378:metabolism; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D051917:Leukosialin; D008099:Liver / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D019009:Proto-Oncogene Proteins c-kit; D011828:Radiation Chimera; D012795:Sialoglycoproteins; D019076:Transgenes / Q000276:immunology*
D015703:Antigens, CD; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D051917:Leukosialin; D012795:Sialoglycoproteins; C497863:Spn protein, mouse; D019009:Proto-Oncogene Proteins c-kit