Bcl-x rather than Bcl-2 mediates CD40-dependent centrocyte survival in the germinal center

Joseph Tuscano, Kirk M. Druey, Agostino Riva, John Pena, Craig B. Thompson, John H. Kehrl

Research output: Contribution to journalArticlepeer-review

85 Scopus citations


Both rapid B-cell proliferation and programmed cell death (PCD) occur during the differentiation and selection of B cells within the germinal center. To help elucidate the role of Bcl-x in B-cell antigen selection and PCD within the germinal center, we examined its expression in defined B-cell populations and by immunochemistry of tonsil tissue. Purified B-cell fractions enriched for centrocytes express high amounts of Bcl-x and relatively low amounts of Bcl-2, whereas fractions enriched for centroblasts lack significant levels of both proteins. Consistent with this observation, immunocytochemistry localized Bcl-x within cella scattered throughout the germinal center. Stimulation of tonsil B cells with either CD40 or Staphylococcus aureus Cowan increases bcl-x mRNA and protein levels. Treatment of a cell line with a germinal center phenotype (RAMOS) or the tonsillar B-cell centroblast fraction with CD40 rapidly increased Bcl-x levels and partially rescued B cells from PCD. These data suggest that Bcl-x rather than Bcl-2 may rescue centrocytes during selection in the germinal center.

Original languageEnglish (US)
Pages (from-to)1359-1364
Number of pages6
Issue number4
StatePublished - Aug 15 1996
Externally publishedYes

ASJC Scopus subject areas

  • Hematology


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