A VH12 transgenic mouse exhibits defects in pre-B cell development and is unable to make IgM+ B cells.
V(H)12 B cells undergo stringent selection at multiple checkpoints to favor development of B-1 cells that bind phosphatidylcholine. Selection begins with the V(H) third complementarity-determining region (CDR3) at the pre-B cell stage, in which most V(H)12 pre-B cells are selectively eliminated, enriching for those with V(H)CDR3s of 10 aa and a fourth position Gly (designated 10/G4). To understand this selection, we compared B cell differentiation in mice of two V(H)12 transgenic lines, one with the favored 10/G4 V(H)CDR3 and one with a non-10/G4 V(H)CDR3 of 8 aa and no Gly (8/G0). Both H chains drive B cell differentiation to the small pre-BII cell stage, and induce allelic exclusion and L chain gene rearrangement. However, unlike 10/G4 pre-B cells, 8/G0 pre-B cells are deficient in cell division and unable to differentiate to B cells. We suggest that this is due to poor 8/G0 pre-B cell receptor expression and to an inability to form an 8/G0 B cell receptor. Our findings also suggest that V(H)12 H chains have evolved such that association with surrogate and conventional L chains is most efficient with a 10/G4 CDR3. Thus, selection for phosphatidylcholine-binding B-1 cells is most likely the underlying evolutionary basis for the loss of non-10/G4 pre-B cells.
Wang
H
H
Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA.
Ye
J
J
Arnold
L W
LW
McCray
S K
SK
Clarke
S H
SH
D000483:Alleles; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D005260:Female; D015328:Gene Rearrangement, B-Lymphocyte, Light Chain; D007143:Immunoglobulin Heavy Chains / Q000235:genetics* / Q000502:physiology; D007075:Immunoglobulin M / Q000096:biosynthesis*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D008231:Lymphopenia / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell; D013234:Stem Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D014162:Transfection
D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region; D008562:Membrane Glycoproteins; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell