Lipopolysaccharide prevents apoptosis and induces responsiveness to antigen receptor cross-linking in immature B cells.


Journal Article

Unlike mature B cells, immature B cells are not activated in response to antigen receptor cross-linking. To examine the mechanisms underlying this unresponsiveness, we have studied the effects of reagents that have been shown to alter the responses of immature B cells to antigen receptor stimulation. Bacterial lipopolysaccharide (LPS) is a polyclonal B-cell activator, and has been shown to interfere with B-cell tolerance induction in vivo and in vitro. Here we show that LPS can also overcome the unresponsiveness of immature B cells to stimulation with anti-receptor (anti-mu) antibodies. LPS synergizes with anti-mu to induce a proliferative response that exceeds the response of immature B cells to LPS alone. Moreover, pretreatment of immature cells with LPS allows them to proliferate in response to subsequent stimulation with anti-mu antibodies. This induction of responsiveness to anti-mu requires exposure to LPS for at least 8 hr. Although the mechanisms of induction are not fully understood, one component of the LPS effect appears to involve enhancement of immature B-cell survival in culture. Neonatal splenic B cells undergo spontaneous apoptosis at a much higher rate than mature B cells, but we have found that LPS causes a dramatic inhibition of apoptosis, even when it is present for only the first 8 hr of culture. The ability of LPS to promote survival of immature B cells and allow them to proliferate in response to antigen receptor stimulation provides a system for investigation of the biochemical mechanisms of unresponsiveness and tolerance susceptibility.

Full Text

Cited Authors

  • Wechsler-Reya, RJ; Monroe, JG

Published Date

  • November 1996

Published In

Volume / Issue

  • 89 / 3

Start / End Page

  • 356 - 362

PubMed ID

  • 8958047

Pubmed Central ID

  • 8958047

Electronic International Standard Serial Number (EISSN)

  • 1365-2567

International Standard Serial Number (ISSN)

  • 0019-2805

Digital Object Identifier (DOI)

  • 10.1046/j.1365-2567.1996.d01-749.x


  • eng