Nic tissue colonization on account of the inability to restrain Th responses.Additional recently, it was shown for the initial time that PSA is involved in theClinical Translational ImmunologyFigure PSA the light side and also the dark side with the force.Beneficial (left side) and deleterious (proper side) effects of capsular Polysaccharide A (PSA) from the symbiont Bacteroides fragilis during interaction together with the host.Immunomodulation by commensal bacteria LA Lobo et alinduction of FoxpTregs expressing the ectoATPase CD in human CD T cells.Acting together with CD, CD prevents inflammation by converting proinflammatory extracellular ATP into antiinflammatory adenosine.The high expression of CD is amongst the mechanisms by which Tregs play their suppression function.Therapy with B.fragilis abrogates encephalomyelitis autoimmune experimental improvement, a model of many sclerosis, and this impact will depend on PSA expression.In line with this, purified PSA from B.fragilis prevents central nervous system (CNS) demyelination and inflammation by inducing Tregs expressing CD in a TLRdependent manner, constant with findings observed in colitis.This polysaccharide can also be capable to shape the migratory patterns of ILproducing CD Tregs, growing their numbers inside the CNS and attenuating the inflammatory response in the Rusalatide Technical Information course of encephalomyelitis autoimmune experimental.Absence of CD expression impairs accumulation of Treg and promotes elevated ThTh response inside the CNS.In summary, these data indicate that PSAexpressing B.fragilis modulates each intestinal and extraintestinal inflammation, which results in autoimmunity.In addition to the welldescribed antiinflammatory functions of PSA, the uptake of this polysaccharide by antigen presenting cells (APCs) benefits in its processing and presentation by way of MHC class II molecules, top to recognition by naive CD T cells.This antigenic presentation is mediated by IFNproducing Th cells inside a TLRdependent proinflammatory manner, demonstrating a crucial function of B.fragilis during peritonitis and intraabdominal sepsis.The duality of proinflammatory versus antiinflammatory effects of the PSA can be explained by variations in its localization (intestinal mucosa versus peritoneum) and also the availability of molecules with adjuvant properties.Hence, this distinctive polysaccharide PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21471984 possesses the capacity to elicit dichotomous Tcell responses via TLR activation (i) intrinsically on CD T cells, top to Treg development and suppressive function, and (ii) straight on APCs to promote IL and IFN production and to drive Th profile by rising costimulatory molecules expression, This proinflammatory arm induced by PSA from B.fragilis is going to be discussed within the next section, exactly where we intend to focus on pathogenic role of B.fragilis outdoors the gut, because the main causative agent of peritoneal infection.B.fragilis within the extraintestinal environment lessons from peritonitis and intraabdominal sepsis In spite of its protective function, the bacteria that constitute our gut microbiota may perhaps be involved in serious pathogenic processes.In instances where the epithelial barrier in the gut is disturbed and breached, commensal bacteria escape the gut lumen, invade the peritoneal cavity and cause peritonitis.Peritonitis is the inflammation on the peritoneum, a membrane that lines the inner wall in the abdominal cavity.In an effort to stop bacterial spread, abscesses create within the peritoneal cavity.Several illnesses are involved in epithelial rupture, contributing for the.