TLR4 and MyD88 control protection and pulmonary granulocytic recruitment in a murine intranasal RSV immunization and challenge model

An intranasal vaccine composed of Toll-like receptor 2 (TLR2) ligand Neisseria meningitidis outer membrane proteins and Toll-like receptor 4 (TLR4) ligand Shigella flexneri lipopolysaccharide (LPS) (Protollin) and enriched respiratory syncytial virus (RSV) proteins (eRSV) has been demonstrated to promote balanced Th1/Th2 responses without eosinophil recruitment and to protect against challenge in mouse models. We used TLR2, TLR4 and myeloid differentiation factor 88 (MyD88) knock-out (-/-) mice to investigate the roles of these signalling pathways on immunogenicity, protection and pulmonary infiltrates following RSV immunization and challenge. Antigen-specific systemic and mucosal antibody production was significantly impaired only in TLR4-/- mice following Protollin–eRSV immunization. In contrast, an intact MyD88 pathway was crucial to elicit a balanced type 1:type 2 immune response, characterized by increased splenocyte production of antigen-induced IFNγ and IL-10 with concomitant reduction of IL5, IgG2a isotype switching and abrogation of pulmonary eosinophil recruitment following challenge. MyD88-dependent signalling also contributed to neutrophil recruitment to the lungs following immunization with eRSV antigen, in the presence or absence of Protollin, compared to a mock antigen or vaccine. Both TLR4 and MyD88-signalling were required for optimal protection against challenge. The upregulation of early signalling molecules IFN-β, TNFα, CD40 and CD86 were studied in splenocytes isolated from naïve TLR2, TLR4 and MyD88-/- mice following stimulation with vaccine components. Splenocytes from TLR4-/- mice displayed reduced IFN-β while those of MyD88-/- mice elicited less TNFα and lower expression of CD40 and CD86 on CD11c+ cells. Together, our results suggest that optimal immunogenicity and protection against RSV without risk of enhanced pulmonary inflammation requires intact TLR4/MyD88-dependent signalling.     

黄芪对新生儿窒息后血清诱导人肾小管细胞TLR_4/MyD88表达的影响

目的:探讨黄芪(Astragalus)对新生儿窒息后血清诱导人肾小管上皮细胞(HK-2)TLR4/MyD88(Toll-like receptors 4/myeloid differentiation factor 88)表达的影响。方法:以人HK-2为研究对象,分为对照组、窒息组、黄芪组,以200 ml/L窒息血清作为攻击因素,分别检测如下指标:倒置相差显微镜观察细胞形态变化;流式细胞仪(Flow Cytometry,FCM)检测各组细胞TLR4特异性荧光抗体阳性结合率表达情况;采用免疫组织化学法(SP法)检测各组细胞MyD88表达情况。结果:与对照组相比较,窒息组细胞形态变化显著,TLR4特异性荧光抗体阳性结合率和MyD88明显增加;与窒息组相比较,黄芪组细胞形态明显改善,TLR4特异性荧光抗体阳性结合率和MyD88的表达明显减少,差异具有统计学意义(P<0.05)。结论:黄芪具有减轻新生儿窒息后血清诱导的人肾小管上皮细胞TLR/MyD88表达的作用。     

黄芩汤对非酒精性脂肪肝炎大鼠的作用及机制研究

目的:研究黄芩汤对非酒精性脂肪肝炎(non-alcoholic steatohepatitis,NASH)的作用及机制。方法:将大鼠随机分为空白组、模型组、阳性对照组(多烯磷脂胆碱,8 mg·kg^-1)、黄芩汤低、中、高剂量组(5,10,20 g·kg^-1),采用高脂饮食饲喂12周造模。灌胃给药5周后,检测各组大鼠血脂、肝功能及炎性因子水平;HE染色观察肝脏组织病理变化;RT-PCR和Western Blot法检测肝组织Toll样受体2(TLR2)、髓样分化因子88(MyD88)、核因子κB p65(NF-κB p65)、白介素6(IL-6)、维甲酸相关核孤儿受体γt(RORγt)、IL-23和IL-17 mRNA和蛋白表达;免疫组化法检测肝组织中NF-κB p65表达。结果:与空白组比较,模型组大鼠血脂、肝功能和炎性因子水平明显异常(P<0.01)。肝组织出现脂肪变性及炎性浸润;肝组织中TLR2、MyD88、NF-κB p65、IL-6、RORγt、IL-23和IL-17 mRNA和蛋白表达明显升高(P<0.01);NF-κB p65阳性细胞表达明显提升(P<0.01)。与模型组比较,黄芩汤组大鼠血脂、肝功能和炎性因子水平得到明显恢复(P<0.05,P<0.01);肝组织脂肪变性和炎性浸润得到纠正;上述蛋白mRNA和蛋白表达均明显降低(P<0.05,P<0.01);NF-κB p65阳性细胞表达明显降低(P<0.01)。结论:黄芩汤可能通过抑制TLR2/MyD88/NF-κB信号通路和IL-23/IL-17轴治疗NASH。     

The adapter proteins of TLRs,TRIF and MYD88, are upregulated in depressed individuals

Background and aims. TRIF and MYD88 are intracellular adaptor proteins for TLR signaling, and altered expression of these molecules can lead to defective or unregulated immune responses. Furthermore, previous studies revealed that depression may alter immune responses, but its mechanisms of action are unclear yet. There is a possibility that immunity and depression are linked through molecules such as TRIF and MYD88, thus, the aim of this study was to evaluate the mRNA levels of TRIF and MYD88 in the PBMCs isolated from depressed medical students. Material and methods. The current study examined 38 depressed medical students studying in Iran and 43 healthy students from the same cohort as a control group. The mRNA levels of TRIF and MYD88 were examined in parallel with a housekeeping gene using real-time PCR. Results. Our results demonstrated that expression of TRIF and MYD88 were significantly elevated in PBMCs isolated from depressed patients when compared to healthy subjects. Conclusions. Based on the current results, it seems that chronic inflammation in depressed patients correlates to the over expression of TRIF and MYD88 genes. Our results show a possible link between the reported increases of chronic inflammation in depressed individuals with unbalanced expression of genes that regulate immunity.     

The therapeutic potential of a kallikrein inhibitor for treating hereditary angioedema

Hereditary angioedema (HAE) manifests as intermittent, painful attacks of submucosal oedema affecting the larynx, gastrointestinal tract or limbs. Currently, acute treatment is available in Europe but not USA, and requires intravenous administration of a pooled blood product. HAE is most likely caused by dysinhibition of the contact cascade, resulting in overproduction of bradykinin. DX-88 (ecallantide, Dyax Corp.) is a highly specific recombinant plasma kallikrein inhibitor that halts the production of bradykinin and can be dosed subcutaneously. In a placebo-controlled Phase II trial in patients with HAE, DX-88 resulted in significant improvement in symptoms compared with placebo. A Phase III trial is ongoing. This review explains the pathophysiology of HAE and the mechanism by which DX-88, a non-intravenous, nonplasma-derived therapy, might improve the disease, and discusses the clinical course of HAE and available treatments. Finally, it explores the potential value and efficacy of DX-88 in treating HAE.     

中药口腔溃疡复合膜的研制

中药口腔溃疡复合膜为一中药新剂型,由药膜与覆盖膜构成。对不同配方和材料的成膜性,粘附性及释药性的比较表明,以PVA_17-88-CMCNa(1:1)为药膜基质,PVA_17-88为覆盖膜材料较为理想。     

MH134-88体外细胞系的建立及其生物学特性的研究

MH134-88是将用四氯化碳诱发成功的C_3H/HeN系小鼠的腹水型肝癌株(MH134)经极限稀释及克隆化方法在体外培养,连续传代而建成的一个纯度较高的小鼠肝癌细胞系。MH134呈悬浮培养,生长迅速,特性稳定,迄今已传200余代。本文对其生物学特性进行了较系统的观察与研究。支原体检测阴性,具有较大推广应用的价值。     

Three weeks'' and six months'' exposure to aromatic white spirit affect synaptosomal neurochemistry in rats

The effects of 3 weeks' or 6 months' inhalation exposure of rats to aromatic white spirit 6 h/day, 5 days/week at 0, 400, or 800 ppm were studied. Synaptosomal neurochemistry was investigated as index of the in situ conditions in the presynaptic nerve terminal. In both studies, the relative and absolute yield of synaptosomal protein were significantly reduced in the two exposed groups. Both studies demonstrated increased synaptosomal noradrenaline (NA), dopamine (DA), and 5-hydroxytryptamine (5-HT) concentrations, high-affinity 5-HT uptake rate and uptake capacity. It is hypothesized that a reduced density and total number of synapses in situ may be functionally compensated by increased NA, DA, and 5-HT neurotransmitter release, or by increased activity of corresponding neurons. The increased synaptosomal 5-HT uptake rates and uptake capacities may explain the previously demonstrated increased global and regional neurotransmitter concentrations and the present finding of increased synaptosomal 5-HT concentrations. These changes are interpreted as an indication of toxic effect on the CNS function and are considered supportive of recent findings of electrophysiological changes and affected motor activity following 6 months' exposure to dearomatized white spirit followed by an exposure-free period.     

Molecular cloning and functional characterization of porcine MyD88 essential for TLR signaling

We isolated cDNA encoding porcine MyD88 （poMyD88） from Peyer＇s patches （Pps） of GALT. The complete open reading frame （ORF） of poMyD88 contains 879 bp encoding a deduced 293 aa residues. The amino acid sequence of poMyD88 was characterized by N-terminal death, intermediate and C-terminal Toll/IL-1 receptor （TIR） domains. The putative poMyD88 protein shares a higher level of homology with its human （87.2% amino acid identity） than with its mouse （77.4% amino acid identity） counterpart. Overexpression of poMyD88 participated in the further enhanced activation of NF-w.B in human embryonic kidney （HEK） 293 cells expressing porcine TLR2 and porcine TLR4/MD-2, but not porcine RP105/MD-1 after stimulation with the corresponding ligands. The expression levels of MyD88 were highest in the spleen and mesenteric lymph nodes （MLNs）, and lower in digestive tissues of newborn swine. In adult swine, the expression levels in the digestive tissues were lower than those in MLNs and the spleen. These results suggest that an MyD88-dependent signaling pathway is present in newborn as well as in adult swine and that it is involved in the innate immune system of these animals.