Referenced in: none

Automatically associated channels: Slo1

Title: ATP-gated ionotropic P2X7 receptor controls follicular T helper cell numbers in Peyer's patches to promote host-microbiota mutualism.

Authors: Michele Proietti, Vanessa Cornacchione, Tanja Rezzonico Jost, Andrea Romagnani, Caterina Elisa Faliti, Lisa Perruzza, Rosita Rigoni, Enrico Radaelli, Flavio Caprioli, Silvia Preziuso, Barbara Brannetti, Marcus Thelen, Kathy D McCoy, Emma Slack, Elisabetta Traggiai, Fabio Grassi

Journal, date & volume: Immunity, 2014 Nov 20 , 41, 789-801

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/25464855

Abstract
Microbial colonization of the gut induces the development of gut-associated lymphoid tissue (GALT). The molecular mechanisms that regulate GALT function and result in gut-commensal homeostasis are poorly defined. T follicular helper (Tfh) cells in Peyer's patches (PPs) promote high-affinity IgA responses. Here we found that the ATP-gated ionotropic P2X7 receptor controls Tfh cell numbers in PPs. Lack of P2X7 in Tfh cells enhanced germinal center reactions and high-affinity IgA secretion and binding to commensals. The ensuing depletion of mucosal bacteria resulted in reduced systemic translocation of microbial components, lowering B1 cell stimulation and serum IgM concentrations. Mice lacking P2X7 had increased susceptibility to polymicrobial sepsis, which was rescued by Tfh cell depletion or administration of purified IgM. Thus, regulation of Tfh cells by P2X7 activity is important for mucosal colonization, which in turn results in IgM serum concentrations necessary to protect the host from bacteremia.