Latent Upregulation of Nlrp3, Nlrc4 and Aim2 Differentiates between Asymptomatic and Symptomatic Trichomonas vaginalis Infection

Trichomonas vaginalis is a parasitic protozoan that causes trichomoniasis. The involvement of NLRP3 inflammasome in trichomoniasis has been discussed in recent studies. The present study aimed to find out the involvement of Nlrp3, Nlrc4, and Aim2 in the BALB/c mouse model infected with symptomatic and asymptomatic isolates of T. vaginalis by quantitative real-time PCR and immunohistochemistry. Our results showed a significantly increased expression of Nlrp3 in the vaginal tissue of the symptomatic group on the 2(nd) dpi and 14(th) dpi in the asymptomatic group, respectively. The cervical tissue of asymptomatic groups expressed higher Nlrp3 on 14(th) dpi than the symptomatic group. The Nlrc4 was expressed on 14(th) dpi in the vaginal and cervical tissues of mice infected with asymptomatic group as compared to the symptomatic group. Aim2 expression in vaginal tissue was highest at early time points in both the infected groups as compared to controls. However, in cervical tissues, a significant increase of Aim2 expression was observed on 14(th) dpi in asymptomatic as compared to the symptomatic group. The significantly higher expression of caspase-1 and caspase-4 was observed in cervical tissues of the asymptomatic group on 14(th) dpi as compared to the symptomatic group, respectively. All NLRs together resulted in higher IL-1 beta expression in the vaginal tissues of the symptomatic and asymptomatic groups. We conclude from this study that early expression of Nlrp3, Nlrc4, and Aim2 was seen in the symptomatic group as compared to the late-onset asymptomatic in the vaginal and cervical tissues.