Intranasal immunisation with a 62 kDa proteinase combined with cholera toxin or CpG adjuvant protects against Trichomonas vaginalis genital tract infections in mice

Trichomonosis, caused by the protozoan parasite Trichomonas vaginalis, is one of the most frequent sexually transmitted diseases and is widely spread in all continents. Trichomonas vaginalis as well as other protozoan organisms have high levels of proteolitic activity mainly of the cysteine–proteinase type. This activity is necessary for recognition and adhesion of the parasite to the superficial epithelial cells of the host. In the present study, we show that intranasal immunisation with a 62 kDa cysteine–proteinase purified from T. vaginalis excretion–secretion products in combination with cholera toxin or with synthetic oligodeoxynucleotides (ODN) that contain unmethylated CpG motifs (CpG–ODN) elicits 62 kDa specific IgG and IgA in vaginal lavage fluid and specific IgG in serum. This immunisation protocol resulted in enhanced elimination of parasites following intravaginal challenge of BALB/c mice.