Abstract: ［Abstract］〓Objective〖HTSS〗〓To investigate the negative regulatory effect of tumor necrosis factoralphainduced protein8 like2 protein（TIPE2） on mycoplasma pneumoniae pneumonia(MPP) and its mechanism. 
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓A total of 142 children with MPP were selected and divided into MPP group(78 cases) and refractory mycoplasma pneumoniae pneumonia(RMPP, 64 cases) according to their clinical manifestations. The changes of TIPE2 expression in peripheral blood of all children were detected and compared with the changes of TIPE2 expression in peripheral blood of 65 healthy children. The level of TIPE2 after infection with mycoplasma pneumoniae(MP) was tested in a cell assay.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓The levels of TIPE2 mRNA in peripheral blood mononuclear cells in children with MPP and RMPP were lower than those in control group， and those in RMPP group were lower than those in normal MPP group(P＜005). With the increase of MP concentration, TIPE2 mRNA and protein gray value of THP1 cells differentiated into macrophages were gradually decreased(P＜005). MP concentration and TIPE2 mRNA and protein expression were negatively correlated(P＜005). The amount of IL6, TNFα and IL1β secreted by macrophages was significantly increased after infected with MP, and the highest secretion of IL6, TNFα and IL1β was found when the concentration of MP was 50 CFU/cell(P＜005). The levels of IL6, TNFα and IL1β were significantly increased with the increasement of MP stimulation at 50 CFU/cell(P＜005). The levels of IL6, TNFα and IL1β in SiRNA group were significantly higher than those in nonSiRNA group(P＜0.05).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓The level of TIPE2 expression in children with MP infection was significantly lower and negatively correlated with the severity of the disease. In vitro experiments show that MPP can inhibit TIPE2 expression, and TIPE2 can inhibit the MAPK pathway, which negatively regulate the level of inflammatory cytokines.

Key words: mycoplasma pneumoniae； tumor necrosis factoralphainduced protein8 like2 protein, inflammatory factor