| Background:As one of the most common pathogens of sexually transmitted diseases,Chlamydia trachomatis infection incidence in genital tract infections is now 4.7%in south China.The problem of infertility caused by Chlamydia trachomatis infection is becoming more and more serious,so it is very important to clarify the pathological changes of host cells after infection.It is also crucial to reduce the incidence of infertility.Studies had found that the host immune response caused by Chlamydia trachomatis infection can induce IL-1β,IL-18,TNF-α,which play an important role in pyroptosis.In other types of Chlamydia,such as lung type,studies have confirmed that CT infection can lead to pyroptosis.Therefore,we speculate that Chlamydia trachomatis infection will cause pyroptosis in host cell.CGAS-STING signaling pathway is an important inflammatory factor production pathway in inflammatory infection.Our previous experiments show that the expression of STING was increased in Chlamydia trachomatis infected HeLa cells.It is unknown whether cervical epithelial cells after Chlamydia trachomatis infection have pyroptosis and the relationship between cGAS-STING signal pathway and pyroptosis.In conclusion,we propose a hypothesis that cervical epithelial cells infected with Chlamydia trachomatis can regulate the pyroptosis in host cells through cGAS-STING signal pathway.In our study,we established a cell model of Chlamydia trachomatis infection and used STING agonists and inhibitors to further clarify whether cells can cause pyroptosis through cGAS-STING signal pathway,so as to further clarify the mechanism of Chlamydia trachomatis infection and infertility,and provide new ideas for reducing CT infection and infertility.Objective:Our group has successfully cultured Chlamydia trachomatis in the early stage,and many studies have shown that after Chlamydia trachomatis infection,the host cell will inhibit the occurrence of apoptosis in the early stage of Chlamydia trachomatis infection to provide sufficient nutrition for Chlamydia trachomatis reproduction.In the later stage of Chlamydia trachomatis infection,it is necessary for Chlamydia trachomatis to promote cell death to facilitate the release of Chlamydia trachomatis inclusion bodies from host cells.As a programmed death of inflammatory cells,pyroptosis is few reported on Chlamydia trachomatis infection.In this study,we intend to establish HeLa cell model of Chlamydia trachomatis infection to determine whether cell pyroptosis occurs at different times after Chlamydia trachomatis infection,and use STING agonists and inhibitors to determine whether the pyroptosis in host cells is regulated by cGAS-STING signal pathway,so as to further clarify the mechanism of Chlamydia trachomatis infection and infertility,and provide new ideas for reducing CT infection and infertility.Methods:Western blot was used to detect the expression of STING related factors(cGAS,STING,IRF3)and pyroptosis related factors(GSDMD,Caspase-1 and Caspase-4/11)at different time periods.The expression of IL-1β,IL-18 and TNF-α was detected by ELISA.The formation of inclusion bodies of Chlamydia trachomatis was detected by immunofluorescence and Giemsa staining.STING agonists and inhibitors were used to treat infected HeLa cells,and the expression of the above factors was detected by the same method.Results:The expression of STING related factors was the highest at about 20-32h,and the expression of pyroptosis related factors was the highest at about 24-32h.After STING stimulation,the expression of IFN-1β is quite different from the stimulation results of STING.The expression of other factors of STING and pyroptosis related factors is basically consistent with the expression of STING.STING stimulation can promote the formation of Chlamydia trachomatis inclusion bodies.Conclusion:1.After Chlamydia trachomatis infected HeLa cells,HeLa cells will occur pyroptosis.2.After infects HeLa cells,the occurrence of cell pyroptosis is regulated by cGAS-STING signal pathway. |
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