commensal-induced regulatory t cells mediate protection against pathogen-stimulated nf-κb activationcommensal-induced调节性t细胞调节保护pathogen-stimulated nf-κb激活.pdfVIP

Commensal-Induced Regulatory T Cells Mediate Protection against Pathogen-Stimulated NF-kB Activation 1 1 2 2 2 2 Caitlin O’Mahony , Paul Scully , David O’Mahony , Sharon Murphy , Frances O’Brien , Anne Lyons , 2 2 2 1 1,2 Graham Sherlock , John MacSharry , Barry Kiely , Fergus Shanahan , Liam O’Mahony * 1 Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland, 2 Alimentary Health Ltd., University College Cork, Cork, Ireland Abstract Host defence against infection requires a range of innate and adaptive immune responses that may lead to tissue damage. Such immune-mediated pathologies can be controlled with appropriate T regulatory (Treg) activity. The aim of the present study was to determine the influence of gut microbiota composition on Treg cellular activity and NF-kB activation associated with infection. Mice consumed the commensal microbe Bifidobacterium infantis 35624 followed by infection with Salmonella typhimurium or injection with LPS. In vivo NF-kB activation was quantified using biophotonic imaging. CD4+ + + + CD25 Foxp3 T cell phenotypes and cytokine levels were assessed using flow cytometry while CD4 T cells were ¨ isolated using magnetic beads for adoptive transfer to naıve animals. In vivo imaging revealed profound inhibition