Observation On The Changes Of Skin And Lung Pattern Recognition Receptors And Cytokines Infected With Microsporum Gypseum In Mice

Objective: The aim of this study was to investigate the dynamic changes of Dectin-1,TLR-2 and TLR-4 receptors and cytokines in the skin and lung tissues of mice infected with Microsporum gypseum.Method: The C57BL/6 mice were subcutaneously inoculated M.gypseumfrom giant panda,and the lesioned skin tissues were observed on the 3rd,7th and 14 th day by PAS staining and HE staining to observe the spore colonization site and pathological damage.The KM mice were injected intravenously with giant M.gypseum,and the body weight changes of the mice were recorded for 7 th days and the survival rate of the mice was recorded for 30 th days.The fungal load,organ index and histopathology was collected at the day 2nd,5th and 9th assesses fungal load and pathological damage in the heart,liver,spleen,lungs and kidneys.The transcriptional expression levels of three receptors and 14 cytokine mRNAs were quantified by qRT-PCR on mouse lung tissues at the day 2nd,5th,9th and 14 th.Immunological staining was performed on mouse lung tissues at the day 2nd,5th and 9th.The recruitment of immune cells in the lungs of infected mice was assessed.Results: The expression of pattern recognition receptor mRNA was detected by real-time PCR at 3rd,6th and 12 th hour.The expression of cytokine mRNA was detected by real-time PCR at 1st,3rd,7th 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 transcriptional expression of the pattern recognition receptor Dectin-1,TLR-2 and TLR-4 increased(p<0.01),the transcriptional expression levels of cytokines IL-6,IL-1?,IL-23,TGF-?,IL-17 A,IL-17 F and IL-22 were increased(p<0.01).The result indicated thatM.gypseum inducedweight loss(p<0.001)in mice,mortality increase(p<0.05)following spores increase.From the results of fungal load,organ index,PAS staining and HE staining,M.gypseum entering the blood circulation were mainly colonized and damaged in the lung.The expression level of pattern recognition receptor and cytokines significantly increased in lung during test period(p<0.05).Fifteen item peaked fast and gradually decreased,among them,12 items(Toll-like receptor(TLR)-2,TLR-4,interleukin(IL)-6,IL-1?,IL-23,IL-10,IL-4,IL-17 A,IL-17 F,IL-22,tumour necrosis factor(TNF)-? and interferon(IFN)-?)peaked at second day after infection,and 3 items(Dectin-1,IL-9 and IL-13)peaked at fifth day.Transforming growth factor-?(TGF-?)and IL-12 peaked at fourteenth day.Conclusions: Upon subcutaneous injection of M.gypseum,the pattern recognition receptor recognizes the M.gypseum surface pattern recognition molecule to activate the Th17 pathway.Differentiated mature Th17 cells secrete cytokines IL-22,IL-17 A and IL-17 F,thereby exerting resistance to M.gypseum.When the mice are deeply infected with M.gypseum,the lung pattern recognition receptor recognizes the surface pattern recognition molecules of the M.gypseum and activates the Th17 pathway.Differentiated mature Th17 cells secrete cytokines IL-22,IL-17 A and IL-17 F,promote the recruitment of neutrophils,macrophages and dendritic cells,thereby exerting resistance toM.gypseum.