Oral vaccination with inhibin DNA delivered using attenuated Salmonella choleraesuis for improving reproductive traits in mice

Abstract

The objective of this study was to examine the efficacy and safety of a novel inhibin vaccine containing inhibin α (1–32) fragments in mice. A recombinant plasmid pVAX‐asd‐IS was constructed by inserting recombinant inhibin α (1–32) and the hepatitis B surface antigen S into the plasmid in which the asd gene, rather than the kanamycin gene, was a selection marker. Ninety Kuming mice were divided into six groups consisting of 15 mice each. First group was (C1) injected with 200 µl of PBS, second (C2) received 1 × 1010 CFU of crp−/asd− C500/pVAX‐asd and served as vector control, third did not receive any treatment (C3), while fourth, fifth, and sixth group received 1 × 1010, 1 × 109, 1 × 108 CFU of the recombinant inhibin vaccine crp−/asd− C500/pVAX‐asd‐IS (group T1, T2, T3), respectively. Western blotting demonstrated that recombinant expressed inhibin protein possessed immune function and that this plasmid could replicate for up to 40 generations stably. Vaccination with this strain at a dose of 1 × 1010 CFU/200 µl per mouse induced high anti‐inhibin antibody levels, significantly increased large‐follicle production in T1 group (p < 0.05) and average litter size (p > 0.05) compared with control groups. Integration studies showed no evidence of inhibin fusion gene integrated into mice's genome 2‐month after immunization. These results suggest that the vaccine described in the present study may provide a safe method to improve reproductive traits in animals. A trend towards increased litter size and significant increase in large follicle population depict that this vaccine may have direct application in large animal industry.

Evaluación de una vacuna de ADN y su péptido recombinante contra inhibina alfa (165-300) sobre la respuesta inmune y fertilidad en ratones

“…El resultado final es la neutralización de la INHA endógena, la cual ejerce una fuerte regulación negativa contra FSH (Knigth et al 2012, 57), permitiendo el (Han et al 2008, 253), o asociadas con otros péptidos (Dan et al 2016a, 18) o antígenos (Han et al 2013, 262 pero con respuestas en incrementos en tamaño de camada menos favorables en ratas (29. 6% Han et al 2008, 260;30.3% Wang et al 2012, 398), ratones tratados con vacunas de ADN de INHA (1-32) (7.…”

Nasal immunization with inhibin DNA vaccine delivered by attenuated Salmonella choleraesuis for improving ovarian responses and fertility in cross‐bred buffaloes

“…In the present study, immunization of C501 (pVAX‐asd‐IS) induced the production of anti‐inhibin antibody in cross‐bred buffaloes and the anti‐inhibin antibody titres in group T1 exhibited an increase following booster immunization. It was also demonstrated that C501 (pVAX‐asd‐IS) elicited effective immune response and increased large follicle production and ovulation in rats and mice (Han et al., ; Hui et al., ). Associated with abundance of inhibin antibody titre, buffaloes of group T1 had the significantly greater number of large follicles and ovulation rate compared with the control group,which confirmed the previous findings that immunization against inhibin increased the ovulation rate and induced multiple ovulation in heifers and goats (Akagi et al., ; Sasaki, Medan, Watanabe, Sharawy, & Taya, ).…”

“…The recombinant pVAX‐asd‐IS plasmid was previously described by our laboratory (Han et al., ) and, it contained IS fusion gene and the pVAX‐asd eukaryotic expression plasmid (Invitrogen, USA). The IS gene encoded inhibin ɑ (1–32) gene was inserted into the hepatitis B surface antigen (HBsAg) S gene.…”

“…Moreover, previous researches carried out in our laboratory indicated that the recombinant inhibin DNA vaccine delivered by attenuated Salmonella choleraesuis could improve production of anti‐inhibin antibodies and stimulate the development of follicles in mice and rats (Han et al., ; Hui et al., ). Comparing with naked DNA vaccination, the production of the attenuated S. choleraesuis ‐mediated inhibin DNA vaccine is easier and relatively low cost, as there is no need to amplify and purify plasmid (Cazorla et al., ; Qu, Wang, Cai, & Du, ), and the vaccine without antibiotic resistance gene is safe for animals and humans.…”

Mucosal IgA and IFN-γ+ CD8 T cell immunity are important in the efficacy of live Salmonella enteria serovar Choleraesuis vaccines

“…The licensed attenuated S. Choleraesuis vaccine, strain C500, is safe, and has been used to prevent swine paratyphoid in China for the past 40 years910. As a facultative intracellular bacterium, the vaccine strain has also been studied as an oral vaccine vector to deliver heterologous protein or DNA vaccine, which provides protection against infectious diseases in addition to paratyphoid1112.…”