Local cytokine/chemokine profiles in BALB/c and C57BL/6 mice in response to T. vaginalis infection

Abstract

Trichomonas vaginalis is the causative agent of Trichomoniasis (a sexually transmitted infection). Recent reports have shown that stimulation of cellular immunity can reduce trichomoniasis infection. Animal studies are essential to understanding the pathogenesis of infection and developing new potential drugs and vaccines to treat the infection. Therefore, we have tried to understand the pathogenesis of T. vaginalis infection by investigating the differences in the expression of chemokine/cytokine levels in vaginal and cervical tissues of BALB/c and C57BL/6 mice. Different pathological symptoms, like desquamation, neutrophil infiltration, and hemorrhage, were recorded in BALB/c and C57BL/6 in response to T. vaginalis infection. Vaginal and cervical tissues of BALB/c showed these symptoms on 2nd dpi, which became severe on 7th dpi and turned to mild or normal till 14th dpi compared to C57BL/6 strain. Immunohistochemistry in the vagina and cervical tissues of BALB/c and C57BL/6 mice was done to assess cytokines at different time intervals post-infection. Significant expression of Interleukin-1β (IL-1β) (a pro-inflammatory cytokine) was found in BALB/c compared to the C57BL/6 mice, on 7th dpi and 2nd dpi in vaginal and cervical tissues, respectively. Higher expression of MIP-2 (neutrophil chemoattractant) was observed in the vaginal tissues of BALB/c mice on 7th dpi compared to the C57BL/6 group. In addition, higher expression of TGF-β (immune-suppressor) was observed on 7th dpi in the vaginal tissue of BALB/c mice. The present study demonstrates that more pathological signs of T. vaginalis infection developed in BALB/c mice than C57BL/6 mice. Also, significant levels of IL-1β and MIP-2 were measured in BALB/c mice in response to T. vaginalis compared to C57BL/6.