Heterogeneity of tonsillar subepithelial B lymphocytes, the splenic marginal zone equivalents

J Immunol. 2000 Jun 1;164(11):5596-604. doi: 10.4049/jimmunol.164.11.5596.

Abstract

The VH4 genes expressed by both resting and in vivo-activated subepithelial (SE) B cells from human tonsils were studied. Resting SE B cells were subdivided according to the presence (IgDlow) or absence (IgM-only) of surface IgD. CD27 was abundant on activated SE B cells and low on resting IgM-only B cells. Resting IgDlow SE B cells could be subdivided into CD27low and CD27high cell fractions. Resting IgDlow SE B cells displayed VH4 genes with a substantial number of mutations (13/29 of the molecular clones were mutated), whereas 25/26 of the clones from resting IgM-only SE B cells were unmutated. Moreover, mutated VH4 genes were detected mainly within the CD27high cell fraction of the IgDlow SE B cells. Several identical unmutated VH4DJH sequences (11/32) were found in different molecular clones from resting IgM-only SE B cells, suggesting local cellular expansion. Both unmutated (14/25) and mutated (11/25) sequences were found in mu transcripts of activated SE B cells. Extensive mutation was observed in the gamma transcripts of activated SE B cells. Therefore, SE B cells are heterogeneous, being comprised of B cells with mutated Ig VH4 genes, that are Ag-experienced B cells, and a subset of B cells with unmutated VH4 genes that are either virgin cells or cells driven by Ags that did not induce or select for V gene mutations.

Publication types

  • Comparative Study

MeSH terms

  • B-Lymphocyte Subsets / cytology*
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / metabolism
  • Child
  • Child, Preschool
  • Epithelium
  • Gene Expression Regulation / immunology
  • Gene Rearrangement, B-Lymphocyte, Heavy Chain
  • Germ-Line Mutation / immunology
  • Germinal Center / cytology
  • Germinal Center / immunology
  • Germinal Center / metabolism
  • Humans
  • Immunoglobulin D / biosynthesis
  • Immunoglobulin M / biosynthesis
  • Immunoglobulin Variable Region / biosynthesis
  • Immunoglobulin Variable Region / genetics
  • Immunophenotyping
  • Interphase / genetics
  • Interphase / immunology
  • Lymphocyte Activation / genetics
  • Molecular Sequence Data
  • Palatine Tonsil / cytology*
  • Palatine Tonsil / immunology*
  • Palatine Tonsil / metabolism
  • Spleen / cytology*
  • Spleen / immunology*
  • Spleen / metabolism
  • Tumor Necrosis Factor Receptor Superfamily, Member 7 / biosynthesis

Substances

  • Immunoglobulin D
  • Immunoglobulin M
  • Immunoglobulin Variable Region
  • Tumor Necrosis Factor Receptor Superfamily, Member 7

Associated data

  • GENBANK/AJ244928
  • GENBANK/AJ244929
  • GENBANK/AJ244930
  • GENBANK/AJ244931
  • GENBANK/AJ244932
  • GENBANK/AJ244933
  • GENBANK/AJ244934
  • GENBANK/AJ244935
  • GENBANK/AJ244936
  • GENBANK/AJ244937
  • GENBANK/AJ244938
  • GENBANK/AJ244939
  • GENBANK/AJ244940
  • GENBANK/AJ244941
  • GENBANK/AJ244942
  • GENBANK/AJ244943
  • GENBANK/AJ244944
  • GENBANK/AJ244945
  • GENBANK/AJ244946
  • GENBANK/AJ244947
  • GENBANK/AJ244948
  • GENBANK/AJ244949
  • GENBANK/AJ244950
  • GENBANK/AJ244951
  • GENBANK/AJ244952
  • GENBANK/AJ244953
  • GENBANK/AJ244954
  • GENBANK/AJ244955
  • GENBANK/AJ244956
  • GENBANK/AJ244957