http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 Chronic Chlamydia pneumoniae infection may promote coronary artery disease in humans through enhancing secretion of interleukin-4 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1055 Atherosclerosis is an inflammatory response, probably to a range of initiating causes. Chronic infection with Chlamydia pneumoniae (C.pn) has been suggested as one cause, but the nature of the association is controversial, in large part due to lack of an identified mechanism to link infection with the atherosclerotic process in man. This study examined 139 consecutive subjects with stable chest pain, with the aim of correlating the serological status of C.pn infection with the pattern of secretion of cytokines from CD4⁺ T lymphocytes. C.pn seropositive subjects secreted significantly more interleukin (IL)-4 than did those who were C.pn seronegative (P = 0·02). No significant difference was noted for secreted interferon (IFN)-γ. The amount of secreted IL-4, but not of secreted IFN-γ, correlated positively with the extent of coronary artery disease (P = 0·006). A similar correlation with secreted IL-4 was not identified with Helicobacter pylori infection. These results support the hypothesis that C.pn infection contributes to the inflammatory process responsible for coronary artery atherosclerosis. The method used to detect cytokine secretion involves ligation of CD40L on blood CD4⁺ T cells, which may have relevance to tissue events. 2010-04-27T06:07:54.271Z ]]> Reversal in fatigued athletes of a defect in interferon γ secretion after administration of Lactobacillus acidophilus http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1108 Background: Fatigue and impaired performance in athletes is well recognised and has been loosely linked to "overtraining". Reduced concentration of IgA in the saliva and increased shedding of Epstein Barr virus (EBV) have been associated with intense training in elite athletes. Objective: To determine whether athletes presenting with fatigue and impaired performance had an immune defect relevant to defective containment of EBV infection, and whether a probiotic preparation (Lactobacillus acidophilus) shown to enhance mucosal immunity in animal models could reverse any detected abnormality. Results: The fatigued athletes had clinical characteristics consistent with re-activation of EBV infection and significantly (p = 0.02) less secretion of interferon (IFN) γ from blood CD4 positive T cells. After one month of daily capsules containing 2 x 1010 colony forming units of L acidophilus, secretion of IFN γ from T cells had increased significantly (p = 0.01) to levels found in healthy control athletes. A significant (p = 0.03) increase in salivary IFN γ concentrations in healthy control athletes after the one month course of L acidophilus demonstrated in man the capacity for this probiotic to enhance the mucosal IFN γ concentration. Conclusion: This is the first evidence of a T cell defect in fatigued athletes, and of its reversal following probiotic therapy. 2010-04-27T06:07:12.734Z ]]> Phagocyte-specific S100 proteins are released from affected mucosa and promote immune responses during inflammatory bowel disease http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5292 Phagocyte-derived S100 proteins are endogenous activators of innate immune responses. S100A12 binds to the receptor for advanced glycation end-products, while complexes of S100A8/S100A9 (myeloid-related proteins, MRP8/14; calprotectin) are ligands of toll-like receptor 4. These S100 proteins can be detected in stool. In the present study we analyse the release of S100A12 and MRP8/14 from intestinal tissue. Specimens from patients with Crohn's disease (CD; n = 30), ulcerative colitis (UC; n = 30), irritable bowel syndrome (IBS; n = 30) or without inflammation (n = 30) were obtained during endoscopy. After 24 h culture, S100A12 and MRP8/14 were analysed in supernatants. Endoscopic, histological, laboratory and clinical disease activity measures were documented. We found an increased spontaneous release of S100A12 from tissue in inflammatory bowel disease (IBD). The release of S100A12 into the supernatants was 28-fold enhanced in inflamed tissue when compared to non-inflamed tissue (mean 46.9 vs. 1.7 ng/ml, p < 0.0001). In active CD, release of S100A12 and MRP8/14 was strongly dependent on localization, with little release from sites of active ileal inflammation compared to colonic inflammation. This difference was more pronounced for S100A12 than for MRP8/14. S100A12 and MRP8/14 provoked up-regulation of adhesion molecules and chemokines on human intestinal microvascular endothelial cells (HIMECs) isolated from normal colonic tissue. The direct release of phagocyte-derived S100 proteins from inflamed tissues may reflect secretion from infiltrating neutrophils (S100A12) and also monocytes or epithelial cells (MRP8/14). Via activation of pattern recognition receptors, these proteins promote inflammation in intestinal tissue. The enhanced mucosal release can explain the correlation of fecal markers with disease activity in IBD. 2010-04-27T04:33:22.010Z ]]>