Effects of severe fever with thrombocytopenia syndrome virus infection on the expression of TLR2 and inflammatory cytokines in mouse peritoneal macrophages / 医学研究生学报

ABSTRACT

Objective The secretion level of inflammatory factors is closely related to the severity of severe fever with thrombocytopenia syndrome (SFTS). This paper mainly discussed the effect of SFTSV infection on the expression of Toll-like receptor 2（TLR2） and inflammatory factors in macrophages in mice. Methods The expression of TLR2 andTNF-α, IFN-β, IL-6, IL-10 and other inflammatory factors were observed at 0, 6, 12, 24, 36, 48, 72 hours after SFTSV infected mice macrophages by qPCR, Western blot and ELISA. Results QPCR results showed that the mRNA levels of TNF-α at 0, 6, 12, 24, 36, 48, 72 h were 0.85±0.14, 15.23±2.45, 28.67±1.59, 94.52±7.05, 55.86±1.82, 23.55±6.15, 9.76±2.03, and the mRNA levels of IFN-β were 0.93±0.21, 1.55±0.33, 14.51±1.98, 55.16±3.64, 26.57±1.49, 9.22±0.51, 5.18±1.06. QPCR results showed that the mRNA levels of TNF-α and IFN-β produced by abdominal macrophages in the infected mice showed a trend of first increasing (the highest at the 24 hour) and then decreasing, and the difference of TNF-α and IFN-β mRNA levels at other time points was statistically significant compared with that at the 0 hour (P<0.05). However, IL-6 and IL-10 mRNA levels continued to increase, and the difference at other time points was statistically significant (P<0.05). ELISA results showed that the expression of four inflammatory factors showed a trend of gradual increase TNF-α 0 and 72 h were (38.31±4.25, 140.41±23.45) pg/mL; IFN-β 0th and 72th were (17.56±0.66, 1084.93±111.42) pg/mL; IL-6 protein 0 and 72 h were (113.30±0.07, 2302.32±134.09) pg/mL; IL-10 protein 0 and 72 h were (515.00±21.21, 2590.40±226.19) pg/mL, respectively, with significant increases at the 24, 36, 48 and 72 hours compared with that at the 0 hour (P<0.05). The expression of TLR2 mRNA generated by mouse peritoneal macrophages showed a trend of first increasing and then decreasing, and increased to the highest level at 24 h, and the difference between each time point and 0 h was statistically significant (P<0.01). The expression of TLR2 gradually increased after infection with time extension. Conclusion SFTSV infection can up-regulate the expression of TLR2 in macrophages, thereby leading to the increased secretion of the cytokines.