title: Loss of precursor B cell expansion but not allelic exclusion in VpreB1/VpreB2 double-deficient mice.
abstract: The pre-B cell receptor consists of immunoglobulin (Ig) mu heavy chains and surrogate light chain, i.e., the VpreB and lambda5 proteins. To analyze the role of the two VpreB proteins, mice lacking the VpreB1 and VpreB2 genes were generated. VpreB1(-/-) VpreB2(-/-) mice were impaired in their B cell development at the transition from pre-BI to large pre-BII cells. Pre-BII cells did not expand by proliferation, consequently 40-fold less small pre-BII and immature B cells were found in bone marrow, and the generation of immature and mature conventional B cells in spleen appeared reduced. In addition, only low numbers of B-1a cells were detected in the peritoneum. Surprisingly, Ig heavy chain allelic exclusion was still active, apparently ruling out a signaling role of a VpreB1/VpreB2-containing receptor in this process.
authors.affiliation: Developmental Immunology, The Babraham Institute, Cambridge CB2 4AT, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Mundt
authors.forename: S
authors.initials: S
authors.lastname: Licence
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
authors.forename: F
authors.initials: F
authors.lastname: Melchers
authors.forename: I L
authors.initials: IL
authors.lastname: Mårtensson
mesh_terms: D000483:Alleles; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001854:Bone Marrow Cells / Q000276:immunology; D019070:Cell Lineage; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D007075:Immunoglobulin M / Q000097:blood; D008213:Lymphocyte Activation; D008221:Lymphoid Tissue / Q000254:growth & development; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell; D013154:Spleen / Q000166:cytology / Q000276:immunology
chemical_list: D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D054420:Pre-B Cell Receptors; D011947:Receptors, Antigen, B-Cell