TLR4 supports the expansion of FasL+CD5+CD1dhi regulatory B cells,which decreases in contact hypersensitivity

Certain B cells termed as “regulatory B cells” (Bregs) can suppress the ongoing immune responses and a splenic CD5⁺CD1d^hi Breg subset identified earlier was shown to exert its regulatory functions through secretion of IL-10. Though FasL expression is an alternative mechanism of immune suppression used by B cells, little is known about the FasL expressing CD5⁺CD1d^hi Bregs. In this study, we isolated splenocytes or splenic CD19⁺ B cells and compared the efficiency of toll-like receptor(TLR)4 ligand (lipopolysaccharide) with TLR9 ligand (CpG), anti-CD40 and TLR9 ligand (CpG) plus anti-CD40 on the FasL expression of splenic CD5⁺CD1d^hi Bregs by flow cytometry. FasL expression in CD5⁺CD1d^hi B cells was rapidly increased after TLR4 ligation. Intriguingly, anti-CD40 and CpG plus anti-CD40 combinations failed to stimulate FasL expression in CD5⁺CD1d^hi B cells although the IL-10 production was up-regulated in this subset. In addition, LPS and other B10-cell inducers increased the expression of surface molecules like CD86 and CD25, which are correlated to the regulatory functions of B cells. Furthermore, NF-κB and NF-AT inhibitors decreased the TLR4-activated FasL expression in CD5⁺CD1d^hi B cells. Then we sorted splenic CD5⁺CD1d^hi Bregs using flow cytometry and found that TLR4-activated CD5⁺CD1d^hi Bregs suppressed the proliferation of CFSE-labeled CD4⁺ T cells in vitro, which was partly blocked by anti-FasL antibody. In oxazolone-sensitized mice having contact hypersensitivity, FasL expression in splenic CD5⁺CD1d^hi B cells was decreased compared to the control group after TLR4 ligation. Our findings suggest that the regulatory function of CD5⁺CD1d^hi B cells could be partly mediated by Fas-FasL pathway and this FasL expressing CD5⁺CD1d^hi Bregs might participate in the regulation of inflammatory diseases.     

肝脏表达的Niemann-Pick C1-Like 1调节小鼠的胆汁胆固醇浓度

目的:探讨人(NPC1L1)在小鼠肝脏的过表达对胆汁胆固醇重吸收的影响。方法:通过杂交NPC1L1基因敲除小鼠(L1-KO)与肝脏过表达人的NPC1L1的转基因小鼠(L1-Tg),获得无小鼠自身NPC1L1基因表达、在肝脏过表达或不表达人NPC1L1基因的小鼠(L1-Tgliv+和L1-Tgliv-)。给予L1-Tgliv+小鼠(实验组)及L1-Tgliv-小鼠(对照组)含0.2%胆固醇的饮食并测定2组小鼠胆汁的脂质分泌、血浆的脂质水平和粪便核心固醇的分泌。结果:与L1-Tgliv-小鼠相比,L1-Tgliv+小鼠的胆汁胆固醇水平降低了90%,同时粪便核心固醇的分泌也降低了10%,而血浆总胆固醇、游离胆固醇和胆固醇酯水平分别升高了38.6%、47.6%和36.6%。结论:小鼠肝脏NPC1L1的过表达可提高肝脏对胆汁中胆固醇的重吸收。     

Impacts of geriatric nutritional risk index on prognosis of patients with non-ST-segment elevation acute coronary syndrome: Results from an observational cohort study in China

Background and aimsIt is recognized that malnutrition increases risk of worse prognosis in patients with various diseases. The present study investigated if poor nutritional status predicts adverse outcomes in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI).Methods and resultsThe study enrolled 2299 patients (mean age: 60.01 ± 8.95 years; 71.8% male) with NSTE-ACS who underwent PCI at Beijing Anzhen Hospital from January to December 2015. The entire cohort was divided into training set (n = 1519) and testing set (n = 780) at a ratio of approximate 2 : 1. Nutritional status was assessed by geriatric nutritional risk index (GNRI). The primary endpoint was a composite of adverse events as follows: all-cause death, non-fatal myocardial infarction (MI) and any revascularization. Multivariate Cox analysis showed that GNRI significantly associated with primary endpoint, independent of other risk factors [hazard ratio (HR) 1.159 per 1-point decrease of GNRI, 95% confidence interval (CI) 1.130–1.189, p < 0.001]. The addition of GNRI to a baseline model had an incremental effect on the predictive value for adverse prognosis in training set [AUC: from 0.821 to 0.873, p < 0.001; category-free net reclassification improvement (NRI): 0.313, p < 0.001; integrated discrimination improvement (IDI): 0.108, p < 0.001]. The incremental effect of GNRI was further validated and confirmed in testing set.ConclusionLower GNRI is a significant predictor of adverse prognosis in patients with NSTE-ACS undergoing PCI. Further studies need to be performed to determine whether nutritional interventions have a positive impact on improving clinical prognosis.