Potent effect of KISS1-54 DNA vaccine compared with KISS1-10 DNA vaccine in inhibiting the fertility of female rats

BACKGROUND Most studies on immunocastration currently focused on male animals. However, immunization of male animals does not completely inhibit sexual behavior and fertility. This study aimed to compare the immunocastration effect of KISS1 DNA vaccines encoding different lengths of kisspeptins in female rats for effective castration effects on both male and female rats. METHODS Fifteen female rats were randomly divided into three groups. The rats in T1 group or T2 group was orally given respectively KISS1-54 or KISS1-10 DNA vaccines with fused tPA signal peptide, and the control group (Group C) was orally administered with empty vector vaccine, at a dose of 5 × 109 CFU/rat at weeks 0, 3 and 6 of the study. Blood samples were collected by retroorbital bleeding before primary immunization and at weeks 3 and 9 after primary immunization. RESULTS Both KISS1-54 and KISS1-10 DNA vaccines induced the body's humoral immune response, and the anti-kisspeptin antibody titres in the T1 group were significantly higher than that in T2 and C groups (p