An evidence for surface expression of an immunogenic epitope of sarcoplasmic/endoplasmic reticulum calcium-ATPase2a on antigen-presenting cells from naive mice in the mediation of autoimmune myocarditis

We recently reported identification of sarcoplasmic/endoplasmic reticulum calcium-ATPase2a (SERCA2a) 971–990, which induces atrial myocarditis by generating autoreactive T cells in A/J mice. However, it was unknown how antigen-sensitized T cells could recognize SERCA2a 971–990, since SERCA2a-expression is confined to an intracellular compartment. In this report, we present evidence that antigen-presenting cells (APCs) from lymphoid and non-lymphoid organs in naïve animals present SERCA2a 971–990 and stimulate antigen-specific T cells. Using major histocompatibility complex (MHC) class II dextramers for SERCA2a 971–990, we created a panel of T cell hybridomas and demonstrated that splenocytes from naïve A/J mice stimulated the hybridoma cells without exogenous supplementation of SERCA2a 971–990. We then recapitulated this phenomenon by using SERCA2a 971–990-specific primary T cells, verifying that the T cell responses were MHC-restricted. Furthermore, SERCA2a 971–990-sensitzed T cells exposed to APCs from naïve mice were found to produce the inflammatory cytokines interferon-γ, granulocyte macrophage colony stimulating factor, and interleukin-17A, which are implicated in the induction of myocarditis. Finally, while T cells exposed to mononuclear cells (MNCs) obtained from heart and liver also responded similarly to splenocytes, endothelial cells (ECs) generated from the corresponding organs displayed opposing effects, in that the proliferative responses were suppressed with the heart ECs, but not with the liver ECs. Taken together, our data suggest that the surface expression of SERCA2a 971–990 by naïve APCs can potentially trigger pathogenic autoreactive T cell responses under conditions of autoimmunity, which may have implications in endothelial dysfunction

Induction of acute respiratory distress syndrome in rats by lipopolysaccharide and its effect on oxidative stress and antioxidant status in lung

278-284Acute lung injury (ALI) or its severe form, acute respiratory distress syndrome (ARDS) is an important cause of mortality in the human population. Despite significant advances made, the mortality associated with ALI remains unchanged. The objective of the present study was to evaluate the role of oxidative stress, alveolar antioxidant status and multiple organ injury in ARDS induced by lipopolysaccharide (LPS) in rats. Rats were divided into 4 groups, group I control rats were given saline intraperitoneally, whereas groups II, III and IV (LPS-treated) rats received an intraperitoneal injection of LPS (10 mg/kg body weight) and sacrificed after various time intervals. In LPS-treated rats, we observed increased levels of oxidative products, decreased levels of antioxidants in lung tissues and increased levels of serum marker enzymes, suggesting multiple organ injury. Bronchoalveolar lavage fluid (BALF) neutrophil content and protein concentration in LPS-treated rats were significantly elevated in a time-dependent manner. Histological studies revealed neutrophil influx and diffused alveolar damage in LPS-administered rats. These results clearly suggested that increased oxidant levels led to oxidative stress, antioxidant deficiency attenuating lung inflammation and tissue damage. LPS administration resulted in multiple organ failure, leading to increased mortality

Evaluation of antihyperlipidemic activity of ethanolic extract of <i style="">Cassia auriculata</i> flowers

54-58Hyperlipidemia is a major risk factor for development of coronary artery disease. Cassia auriculata is traditionally used in India for medicinal purposes. In this study, effect of ethanolic extract of Cassia auriculata flowers (Et-CAF) was investigated in Triton WR1339-induced hyperlipidemic rats. Treatment with the Et-CAF (450 mg/kg b.wt) significantly reduced the total cholesterol (TC), triglycerides (TG) and low-density lipoprotein-cholesterol (LDL) levels and significantly increased the high-density lipoprotein (HDL) level associated with reduction of atherogenic index in hyperlipidemic rats. However, there was no change in the serum lipid profile of normal rats treated with Et-CAF alone. The results suggest that Et-CAF has a beneficial effect in treating hyperlipidemia and may serve as a potential drug for prevention of hyperlipidemic atherosclerosis

Effect of lipopolysaccharide on alteration of phospholipids and their fatty acid composition in spleen and thymus by in vitro metabolic labeling

Lipopolysaccharide (LPS) is an endotoxin, a potent stimulator of immune response and induction of LPS leads to acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). ARDS is a life-threatening disease worldwide with a high mortality rate. The immunological effect of LPS with spleen and thymus is well documented; however the impact on membrane phospholipid during endotoxemia has not yet been studied. Hence we aimed to investigate the influence of LPS on spleen and thymus phospholipid and fatty acid composition by 32P]orthophosphate labeling in rats. The in vitro labeling was carried out with phosphate-free medium (saline). Time course, LPS concentration-dependent, pre- and post-labeling with LPS and fatty acid analysis of phospholipid were performed. Labeling studies showed that 50 mu g LPS specifically altered the major phospholipids, phosphatidylcholine and phosphatidylglycerol in spleen and phosphatidylcholine in thymus. Fatty acid analysis showed a marked alteration of unsaturated fatty acids/saturated fatty acids in spleen and thymus leading to immune impairment via the fatty acid remodeling pathway. Our present in vitro lipid metabolic labeling study could open up new vistas for exploring LPS-induced immune impairment in spleen and thymus, as well as the underlying mechanism

Additional file 2: Figure S2. of Cytosolic phospholipase A2 contributes to innate immune defense against Candida albicans lung infection

Expression of cytokines and chemokines in lung tissue from cPLA2α+/+ and cPLA2α−/− mice during C. albicans infection. Real-time PCR was carried out using the Mouse Cytokines & Chemokines RT2 Profiler PCR Array to compare expression in lungs of cPLA2α−/− (KO) and cPLA2α+/+ (WT) mice challenged with saline or 106 C. albicans (CA) for 12 and 24 h (n = 6-10 mice/group in 3–5 experiments). *P < 0.05 compared to WT saline control; ϕ P < 0.05 compared to WT saline control, # P < 0.05 compared to KO saline control; **P < 0.05 compared to WT with CA. (TIF 859 kb

Additional file 1: Figure S1. of Cytosolic phospholipase A2 contributes to innate immune defense against Candida albicans lung infection

Flow cytometry gating strategy for cell identification in lung digests from cPLA2α+/+ (WT) and cPLA2α−/− (KO) mice challenged with C. albicans for 24 h. Cells were isolated from enzymatically digested mouse lungs, and after exclusion of doublets and debris, immune cells were identified by CD45 staining. A sequential gating strategy was used to identify populations expressing specific markers: a alveolar macrophages (AM) (CD45+ CD24− CD11b− SiglecF+), (b) tissue macrophages (TM) (CD45+ CD24− CD11b+), (c) neutrophils (PMN) (CD45+ CD11b+ Ly6G+) and (d) CD11b+ dendritic cells (CD11b+ DCs) (CD45+ MHCII+ CD11c+ CD11b+). (TIF 954 kb