BAFF and LPS cooperate to induce B cells to become susceptible to CD95/Fas-mediated cell death

ACOSTA RODRIGUEZ EV; CRAXTON A; HENDRICKS DW; MERINO MC; MONTES CL; CLARK EA; GRUPPI A

EUROPEAN JOURNAL OF IMMUNOLOGY

Año: 2007 p. 990 - 990

0014-2980

font face="AdvLT70604" size="2"> Microorganisms with pathogen-associated molecular patterns (PAMP) activate B cells directly by binding to TLR and also indirectly by inducing APC to release cytokines such as BAFF that promote B cell survival. We found that murine B cells activated concomitantly with LPS (TLR-4 ligand) and BAFF are protected from spontaneous apoptosis, but are more susceptible to Fas/CD95-mediated cell death. This increased susceptibility to Fas-induced apoptosis is associated with a dramatic coordinated upregulation of Fas/CD95 and IRF-4 expression through a mechanism mediated, at least in part, by inhibition of the MEK/ERK pathway. Up-regulation of Fas/CD95 by BAFF is restricted to B cells activated through TLR-4, but not through TLR-9, BCR or CD40. TLR ligands dif