Identification of Trichomonas vaginalis α-actinin as the most common immunogen recognized by sera of women exposed to the parasite

A study on presence of antibodies to Trichomonis vaginalis in serum was done on a group of 500 pregnant, asymptomatic Angolan women. A serologic screening, done by ELISA, revealed that 41% of the women had IgG and IgM against the parasite. Analysis of sera by immunoblotting revealed that 94.4% of sera with anti-T. vaginalis IgG class antibodies were reactive against a common immunogenic protein of 115 kDa. The common immunogen was identified as the protozoan α-actinin. All sera recognizing the 115-kDa antigen were reactive against both native and recombinant T. vaginalis α-actinin and nonreactive against human α- actinin. The findings presented in this work offer a new tool for epidemiologic studies and open new perspectives for vaccination.