Canine zona pellucida glycoprotein-3: Up-scaled production, immunization strategy and its outcome on fertility. Issue 1 (1st January 2015)

• Record Type: Journal Article
• Authors: Shrestha, Abhinav; Srichandan, Sudeepa; Minhas, Vidisha; Panda, Amulya Kumar; Gupta, Satish Kumar
• Is Part Of: Vaccine. Volume 33:Issue 1(2015)
• Page Start: 133
• Page End: 140
• Publication Date: 2015-01-01
• Subjects: Adjuvant -- CpG motif -- Immunocontraception -- Recombinant protein produced in fermentor -- Zona pellucida glycoprotein-3; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2014.11.003
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Tag-free recombinant dog ZP3 produced as fusion protein with T-cell epitope of TT in fermentor. E. coli -expressed recombinant protein is immunogenic in female mice. Inhibition of fertility in immunized animals associated with antibody titer against dog ZP3. Inclusion of CpG motif led to enhanced immunogenicity and contraceptive efficacy. Bio-availability of antibodies in female genital tract relevant for contraception. Abstract: Zona pellucida (ZP) glycoproteins based contraceptive vaccines have been proposed for the management of wildlife population. In the present study, a fusion protein encompassing promiscuous T cell epitope of tetanus toxoid [TT; amino acid (aa) residues 830–844] followed by a dilysine linker and an ectodomain of dog ZP3 (ZP3; aa residues 23–348) without any affinity tag (TT-KK-ZP3) has been expressed in Escherichia coli . The recombinant protein was successfully produced in fed-batch fermentor and purified. The average yield of purified refolded protein was 12.20 ± 0.61 mg/2 g wet cell pellet. Female FvB/J mice immunized with the varying doses of recombinant TT-KK-ZP3 supplemented with alum/PetGel A as adjuvants following a three injection schedule, showed dose dependent increase in serum IgG titer. Antibodies against TT-KK-ZP3 recognized native mouse/dog ZP and significantly inhibited mouse in-vitro fertilization ( p = 0.012). Immunized mice showed significant reduction in fertility ( p < 0.05). Higher antibody titers were associated with a decrease in the number of pups born to the immunized female mice. To reduce the number of injections, two injection schedule using various dose combinations of TT-KK-ZP3 supplemented with alum revealed lower immunogenicity and contraceptive efficacy as compared to the three injection schedule. To overcome this, CpG motif was included in addition to alum and both intraperitoneal and intranasal route of immunization following the two injection schedule was investigated. Inclusion of CpG significantly enhanced the antibody titer and improved contraceptive efficacy. In the mice immunized following intraperitoneal route, serum/vaginal IgG and in the mice immunized through intranasal route, vaginal IgA seemed to be important for curtailment in fertility. To conclude, the recombinant protein described herein may be a good candidate for developing contraceptive vaccine for the wildlife population management, in particular street dogs.