Fetal versus adult PreB or B cells: the human VH repertoire.
At the preB stage, when only the IGH locus has rearranged, mu chains become expressed in association with the psi L chains, lambda-like and VpreB, thus forming the preB receptor. By the use of a monoclonal anti VpreB antibody, preB cells were isolated from two adult bone marrow samples, and the VH repertoire was analyzed and compared to fetal, XLA (X-linked agammaglobulinemia), and adult B repertoires. Most VH genes identified were also expressed in fetal liver, XLA bone marrow, and adult PBLs, with similar predominant usage of certain germline genes. Multiple D/D fusions, limited N diversity, and preferential use of JH4 with a low level of DQ52 usage were also identified. Few mutations could be observed, not specifically localized in CDR regions, that could be interpreted as not positively selected. Conversely, a shorter length of CDR3 appeared to be the hallmark of the preB step. Thus, the association of psi L chains with mu does not bring about a bias in the VH gene usage, but a first selection on the CDR3 region could be the result of recognition by given autoantigens or ligands different for preB cells and B cells.
D000328:Adult; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D001853:Bone Marrow / Q000196:embryology / Q000254:growth & development; D001854:Bone Marrow Cells; D002454:Cell Differentiation; D005333:Fetus / Q000276:immunology*; D015322:Gene Rearrangement, B-Lymphocyte; D005803:Genes, Immunoglobulin; D005865:Gestational Age; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D007107:Immune System / Q000196:embryology / Q000254:growth & development; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D008099:Liver / Q000166:cytology / Q000196:embryology; D051379:Mice; D016133:Polymerase Chain Reaction
D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region