High frequency of somatically mutated IgM molecules in the human adult blood B cell repertoire.
Nucleotide sequence analysis of cDNA encoded by the single member of the human immunoglobulin VH6 gene family show that blood B cells in adults, but not in neonates, frequently express somatically mutated IgM molecules. The number of mutations in VH6-encoded cDNA from adult blood ranged from 2 to 19 mutations/VH gene (average 10.1/VH gene). The distribution of silent and replacement mutations suggests that at least some of the VH6 genes were derived from B cells that were activated and selected by antigen. We conclude that the blood B cell repertoire in adult humans, in contrast to its much-studied murine splenic counterpart, is a rich source of highly mutated IgM molecules.
van Es
J H
JH
Department of Immunology, University Hospital Utrecht, The Netherlands.
Meyling
F H
FH
Logtenberg
T
T
D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D005803:Genes, Immunoglobulin; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007075:Immunoglobulin M / Q000032:analysis* / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation
D007143:Immunoglobulin Heavy Chains; D007075:Immunoglobulin M; D007135:Immunoglobulin Variable Region