Validation of the Chlamydia trachomatis genital challenge pig model for testing recombinant protein vaccines.
Chlamydia trachomatis is a Gram-negative obligate intracellular bacterial pathogen that is the leading cause of bacterial sexually transmitted disease in humans in developing countries. A vaccination programme is considered to be the best approach to reduce the prevalence of C. trachomatis infections. However, there are still no commercial C. trachomatis vaccines. In order to develop effective C. trachomatis vaccines, it is important to identify those antigens that elicit a protective immune response, and to develop new and adequate methods and adjuvants for effective vaccine delivery, as conventional methods have failed to induce protective immunity. In order to test different vaccine candidates, animal models are needed. Former studies have used non-primate monkeys, mice or guinea pig infection models. The present study used a pig model for testing recombinant protein vaccines. Two recombinant proteins, polymorphic membrane protein G (PmpG), and secretion and cellular translocation protein C (SctC), were tested for their ability to create protection in a pig C. trachomatis challenge model. The vaccines were administered subcutaneously with GNE adjuvant. Six weeks later, animals were challenged intravaginally with C. trachomatis serovar E. After a further 4 weeks, the pigs were euthanized. PmpG-immunized pigs were better protected than pigs immunized with the less promising SctC candidate vaccine antigen. Interestingly, significant protection was apparently not correlated with a strong humoral immune response upon subcutaneous immunization. In conclusion, the pig model is useful for studying the efficacy of vaccine candidates against genital human C. trachomatis infection.
Schautteet
Katelijn
K
Laboratory of Immunology and Animal Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Stuyven
Edith
E
Laboratory of Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Cox
Eric
E
Laboratory of Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium.
Vanrompay
Daisy
D
Laboratory of Immunology and Animal Biotechnology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000276:immunology* / Q000472:pathogenicity*; D004195:Disease Models, Animal; D005260:Female; D005831:Genital Diseases, Female / Q000276:immunology / Q000473:pathology / Q000517:prevention & control; D006801:Humans; D007279:Injections, Subcutaneous; D008219:Lymphogranuloma Venereum / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control*; D011994:Recombinant Proteins / Q000276:immunology; D012720:Severity of Illness Index; D013552:Swine; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; C410161:PmpG protein, Chlamydia trachomatis; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic