石膏样小孢子菌感染小鼠的Dectin-1、TLR-2和TLR-4及细胞因子动态变化

Dynamic Changes of Dectin-1, TLR-2,TLR-4 and Cytokines in Mice Infected with Microsporum gypseum

本试验旨在研究石膏样小孢子菌经皮肤感染小鼠后皮肤损伤组织中模式识别受体Dectin-1、TLR-2和TLR-4及细胞因子动态变化规律。通过对C57BL/6小鼠皮下接种大熊猫源石膏样小孢子菌,分别在第3、7和14天取病变皮肤组织,经PAS染色和HE染色观察孢子定植部位和病理损伤;分别在第3、6和12小时取病变皮肤组织,用荧光定量PCR检测受体mRNA的转录表达量;分别在第1、3、7和14天取样,用荧光定量PCR检测细胞因子mRNA的转录表达量。结果表明:石膏样小孢子菌感染小鼠后导致皮下脓肿,大量的炎性细胞浸润,并伴有角质层增厚。试验中模式识别受体Dectin-1、TLR-2和TLR-4的转录表达量增加(P<0.01),细胞因子IL-6、IL-1β、IL-23、 TGF-β、IL-17A、IL-17F和IL-22的转录表达量增加(P<0.01)。模式识别受体通过识别病原菌表面模式识别分子而引发免疫反应。本研究表明,机体感染石膏样小孢子菌后,模式识别受体表达显著增加,并通过识别菌体表面模式识别分子从而激活Th17途径,分化成熟的Th17细胞分泌细胞因子IL-22、IL-17A和IL-17F,从而发挥抗菌作用。

The aim of this study was to investigate the dynamic changes of Dectin-1, TLR-2 and TLR-4 pattern recognition receptors and cytokines in skin lesions of mice infected with Microsporum gypseum. M. gypseum from giant panda were subcutaneously inoculated into the C57 BL/6 mice. The skin tissues with pathological changes were collected on the 3 rd, 7 th and 14 th day, then the spore colonization sites and pathological damages were observed by PAS staining and HE staining. The transcription of pattern recognition receptors mRNA were detected by real-time PCR at the 3 rd, 6 th and 12 th hour. The transcription of cytokines mRNA were detected by real-time PCR at the 1 st, 3 rd, 7 th and 14 th day. The results showed that M. gypseum infected mice resulted in a small subcutaneous abscess, a large number of inflammatory cells infiltrated, and accompanied by thickening of the stratum corneum. The transcription of the pattern recognition receptors Dectin-1, TLR-2 and TLR-4 were increased(P<0.01), the transcription levels of cytokines IL-6, IL-1β, IL-23, TGF-β, IL-17 A, IL-17 F and IL-22 were increased(P<0.01). The pattern recognition receptor can recognize the surface pattern recognition molecules of M. gypseum and activate the Th17 pathway, and differentiate the mature Th17 cells into secret cell cytokines IL-22, IL-17 A and IL-17 F, thereby exerting resistance to M. gypseum.