金黄色葡萄球菌isdA基因对宿主上皮细胞免疫指标的影响

Effects of Staphylococcus aureus isdA gene on immunity index in the epithelial cells of the host

目的对金黄色葡萄球菌IsdA的编码基因缺失前后与宿主上皮细胞共孵育后的免疫学进行研究,为进一步研究金葡菌感染机制及抗金葡菌制剂的研究提供依据。方法金黄葡萄球菌野生株Newman和IsdA缺失株NewmanΔIsdA分别作用于上皮细胞Hacat,运用实时荧光定量PCR、ELISA及Western Blot方法检测细胞促炎性细胞因子和趋化因子的分泌情况。结果 PCR结果表明,金黄色葡萄球菌IsdA+/-均能提高上皮细胞分泌促炎性细胞因子(IL-8、TNF-α和IL-6),趋化因子MCP-1,表面受体TLR2和TLR4,C型植物血凝素-1(dectin-1)及抗菌肽LL-37的表达,而IsdA-/-诱导上皮细胞释放细胞因子的能力要低于IsdA+/+,但IsdA-/-组上皮细胞因子水平高于正常对照组;通过ELISA、Western Blot检测与PCR结果一致。结论研究表明,受金黄色葡萄球菌缺失株NewmanΔIsdA作用的上皮细胞促炎症因子分泌减少,细胞表面受体蛋白的表达和转录水平也相应降低,暗示了该缺失株的侵袭力降低,为进一步研究金葡菌感染机制及抗金葡菌制剂提供依据。

In view of the important role of IsdA in colonization and invasion of S. aureus, the immunological study about co-incubation between S. aureus IsdA＋/- and human epithelial cells were progressed. Epithelial cells HaCaT were affected respectively by the wild strains Newman and IsdA deletion mutants NewmanAIsdA of S. aureus. The secretion situation of pro-inflammatory cytokine and chemokine were tested by real-time PCR, ELISA and Western Blot. Results of PCR showed that the expression of pro-inflammatory cytokines （IL-8, TNF-~ and IL-6）, ehemokine MCP-1, the surface receptors TLR2 and TLR4, hemagglutinin C plant-1 （dectin-1）, and the antibacterial peptide LL-37 were raised by S. aureus IsdA＋/- the cy- tokines amount of epithelial cells treated with IsdA/ was lower than that of IsdA＋/＋ , but epithelial cytokines levels of Isd-/- group was higher than that of the control group the results were consistent with that of the PCR through the detection method of ELISA and Western Blot. It＇s showed that S. aureus IsdA-/- could reduce the cytokines secreted by epithelial cells compared with the wild strains IsdA＋/＋ , and the level of cell surface receptor protein transcription decreased accordingly, which hint that invasion force of the deletion mutant decline.