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Generation of Human CD40-activated B cells
13:27

Generation of Human CD40-activated B cells

Published on: October 17, 2009

CD40 inhibits B cell apoptosis by upregulating bcl-xL expression and blocking oxidant accumulation

W Fang1, K A Nath, M F Mackey

  • 1Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455, USA.

The American Journal of Physiology
|March 1, 1997
PubMed

Insights

CD40 signaling protects B cells from apoptosis by increasing Bcl-xL expression and reducing cellular oxidants. This pathway enhances B cell survival and resistance to various apoptotic triggers.

Area of Science:

  • Immunology
  • Cell Biology

Background:

  • CD40 receptor signaling is crucial for B lymphocyte function, including germinal center formation and immunoglobulin class switching.
  • CD40 signaling rescues B cells from apoptosis induced by surface immunoglobulin M cross-linking.
  • Immature B cells are susceptible to apoptosis triggered by various stimuli.

Purpose of the Study:

  • To investigate the role of CD40 signaling in protecting immature B cells from apoptosis.
  • To elucidate the molecular mechanisms underlying CD40-mediated B cell survival.

Main Methods:

  • Utilized the immature mouse B cell line WEHI-231.
  • Stimulated CD40 receptor with recombinant CD40 ligand (CD40L).
  • Induced apoptosis using gamma irradiation, sphingomyelin ceramide, or glutathione depletion.
  • Assessed B cell apoptosis, Bcl-xL expression, intracellular oxidants, and thiol levels.

Main Results:

  • CD40 ligation protected WEHI-231 B cells from apoptosis induced by gamma irradiation, ceramide, and glutathione depletion.
  • CD40 signaling rapidly increased the expression of the anti-apoptotic protein Bcl-xL.
  • CD40 crosslinking diminished the accumulation of intracellular oxidants and preserved intracellular thiols within 1 hour.

Conclusions:

  • CD40 signaling confers generalized cellular resistance to apoptosis in B cells.
  • This resistance is mediated by the upregulation of Bcl-xL and modulation of the intracellular redox potential.
  • CD40 pathway activation represents a significant mechanism for B cell survival.

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