VH Repertoire in Human B Lymphocytes Stimulated by CD40 Ligand and IL-4: Evidence for Positive and Negative Selection Mechanisms Coupled to CD40 Activation

Mol Immunol. 1996 Dec;33(17-18):1369-76. doi: 10.1016/s0161-5890(96)00089-2.

Abstract

In the normal immune system, B cells are thought to be negatively or positively selected at various checkpoints during their maturation; a process that maintains a broad immunoglobulin repertoire while eliminating non-functional or potentially harmful autoreactive antibodies. This study tested the hypothesis that utilization of certain immunoglobulin heavy chain variable region (VH) genes, possibly as a consequence of intrinsic affinity for various ligands, directs positive or negative B cell selection coupled to B cell activation in the periphery during the immune response. The specific prediction that the VH repertoire of CD40-activated B cells would differ from the repertoire of unstimulated cells from the same donor, was tested by assessing VH utilization among human B cell clones grown in vitro, following stimulation with CD40 ligand (CD40L) and IL-4. The results showed that, although utilization of the known VH families and of individual VH3 genes was similar to that found in unstimulated B lymphocytes of the same donor, utilization of individual VH4 genes in CD40-activated B cells displayed a pattern that was markedly different from that of the unstimulated B cells. An allele of V4-61, V4-61b, was over-represented among the activated cells and, in contrast, the V4-34 gene (known to encode cold agglutinins with strong autoreactive properties) was modestly represented among the VH4 activated B cells, although V4-34 was overwhelmingly predominant in the repertoire of resting B cells. These results point to the existence of selection mechanisms that operate during B cell activation in the periphery. These mechanisms may favor B cells utilizing certain VH genes and disfavor the cells that utilize other genes, possibly because utilization of the latter confers autoreactivity.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • CD40 Antigens / genetics
  • CD40 Antigens / immunology*
  • CD40 Ligand
  • Cells, Cultured
  • Humans
  • Immunoglobulin Heavy Chains / genetics*
  • Immunoglobulin Variable Region / genetics*
  • Interleukin-4 / immunology*
  • Ligands
  • Lymphocyte Activation* / genetics
  • Male
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / immunology*
  • Multigene Family / immunology*

Substances

  • CD40 Antigens
  • Immunoglobulin Heavy Chains
  • Immunoglobulin Variable Region
  • Ligands
  • Membrane Glycoproteins
  • CD40 Ligand
  • Interleukin-4