In vitro haemolytic and cytotoxic activity of soluble extract antigen of T. vaginalis isolates from symptomatic and asymptomatic women

Abstract

Human Trichomonas vaginalis infection ranges from asymptomatic to mild, moderate or severe clinical manifestations. The reasons for diverse symptomatology have been found to vary in several attributes and both parasite and host factors appear to play a role in the pathogenesis. The present study reports the in vitro haemolytic and cytotoxic activity of crude soluble extract (CSE) antigen of T. vaginalis isolates from 15 symptomatic and 15 asymptomatic women. The haemolytic activity following the interaction of CSE antigen with human erythrocytes and cytotoxic activity by adding CSE antigen to normal human vaginal epithelial cells was significantly higher with the use of CSE antigen of isolates from symptomatic women as compared to those from asymptomatic women. Furthermore, cytotoxic effect was found to be pH dependent. The study demonstrates, for the first time, the significant effect of parasite antigen of isolates from symptomatic women as compared to those from asymptomatic women in inducing haemolytic and cytotoxic effect and supports the earlier report that contact-independent mechanism(s) may be playing a role in establishing symptomatic trichomoniasis.

Humoral and T cell–mediated immune response against trichomoniasis

“…6 It is observed that T. vaginalis induces haemolytic and cytotoxic activity by both contact-dependent and contact-independent mechanisms. 56 T. vaginalis such as B cells and approximately 50% of T. vaginalis-related leukotoxic activity against B cells was mediated by soluble factors, suggesting that the parasite may kill B cells without direct contact. T. vaginalis-related killing of B cells can also be mediated through a cell contact-dependent manner.…”

“…T. vaginalis can also coat itself with host molecules, thus cannot be recognized by the immune system . It is observed that T. vaginalis induces haemolytic and cytotoxic activity by both contact‐dependent and contact‐independent mechanisms . T. vaginalis such as B cells and approximately 50% of T. vaginalis‐ related leukotoxic activity against B cells was mediated by soluble factors, suggesting that the parasite may kill B cells without direct contact.…”

Trichomonas vaginalis 62 kDa proteinase as a possible virulence factor

“…The different behavior between isolates from symptomatic and asymptomatic patients was also observed by Rojas et al In that report, they found a high correlation between the severity of lesions in mice inoculated intraperitoneally with T. vaginalis strains obtained from infected patients and the severity of clinical manifestations (Rojas et al 2004b). More recently other researchers reported a higher hemolytic and cytotoxic activity with soluble antigens isolated from symptomatic patients (Malla et al 2008). These findings suggested that there were several factors that played an important role in the establishment of symptomatic infection.…”

Involvement of the GP63 protease in infection of Trichomonas vaginalis

“…Second, there were two kinds of TvGP63 according to our predictions-some may have been located on cell membranes (37 members are potential membrane proteins) and others may have been secreted out of the parasite cells (11 members are potential secreted proteins). Experimental evidences have suggested that soluble extract antigen of T. vaginalis isolates from the symptomatic women have cytotoxic activity (Malla et al 2008). We do not have enough knowledge concerning which kinds of GP63 are effectively involved in the parasite cytotoxicity, and since there are so many members of the GP63 family, studies based only on one specific TvGP63 may not really be able to generate any significant results.…”