RF-amide related peptides (RFRP) have been proposed as critical regulators of gonadotropin secretion in mammals. This study was designed to construct a DNA vaccine and investigate the effect of vaccine encoding RFRP-3 on reproduction physiology in ewe. A recombinant vaccine was constructed using two copies of the RFRP-3 gene and HBsAg-S that generate a fusion protein to induce an immunology response. Results showed this recombinant vaccine could produce a significant antibody titer in the treated animals (P < 0.05). The specific RFRP-3 antibody response induced by the vaccine was detected at week 2 with a peak at week 6 after the initial immunization. Furthermore, we found that ewes inoculated with pVAX-tPA-HBsAg-S-2RFRP-asd vaccine significantly raised the concentration of GnRH, LH and E2 in serum compared to the control group. LH and E2 concentration in the treated ewes (Group T) was significantly higher than that in control ewes (Group C) at weeks 10, 12 and 14 after the initial immunization, respectively (P < 0.05). Therefore, RFRP-3 can be used as a target for DNA immunization to promote reproductive hormone secretion in ewes and RFRP-3 gene immunization might be a candidate tool to regulate mammal reproduction.
Keywords: DNA vaccine; RFRP-3; Reproduction hormone; Sheep.
Copyright © 2023 Elsevier Inc. All rights reserved.