Recombinant chimeric protein PSPF as novel vaccine against Streptococcus pneumoniae

Global Medical Microbiology Summit & Expo

November 28-29, 2016 San Francisco, USA

Alexander Suvorov, Galina Leontieva, Ilya Dukhovlinov, Anton Orlov, Tatiana Kramskaya, Irina Koroleva, Susana Alvarez and Julio Villena

Institute of Experimental Medicine, Russia
CERELA-CONICET, Argentina
Saint-Petersburg State University, Russia

Scientific Tracks Abstracts: J Med Microb Diagn

Abstract :

Objectives: Streptococcus pneumoniae is the leading cause of bacterial infections among adults and children. Recombinant polypeptides vaccines, based on the conservative and immunogenic sites of surface pneumococcal proteins could be an advantageous vaccine alternative. Methods: A chimeric recombinant protein named PSPF was constructed from conservative and immunogenic fragments of S. pneumoniae surface proteins PspA, Spr1875, PsaA and the S. typhiurium flagellin terminal domains FliC1 and FliC2. PSPF protein was expressed in E.coli and used for immunization of the inbred or line mice (BALB/c and Albino Swiss) which were later infected with different S. pneumoniae serotypes. Specific humoral immune response was evaluated by ELISA. Protective efficacy was evaluated according to survival rates or lung and blood bacterial cell counts. Experiments with animals were performed with the necessary ethical requirements. Results: PSPF showed a high immunogenic activity when applied by intranasal or subcutaneous routes. Specific IgM, IgG and IgA were detected in serum and broncho-alveolar fluid. PSPF-specific IgG recognized all S. pneumoniae serotypes studied. PSPF immunization increased resistance of adult BALB/c mice to lethal intraperitoneal infection with serotype 19F (25-40%) and intranasal infection with serotype 3 (25%). PSPF-immunized infant Swiss mice showed an improved clearance of serotypes 3, 6�?, 14 and 19F from the lungs and complete absence in blood. The addition of Lactobacillus rhamnosus strain as PSPF adjuvant significantly improved results of vaccination. Conclusion: Studies in mice models demonstrated that recombinant chimeric protein PSPF is immunogenic and improves protection against S. pneumoniae infection.

Biography :

Alexander Suvorov is presently acting as Head of Molecular Microbiology division of Federal, State Budgetary Scientific Institution "Institute of Experimental Medicine” in Russia.

Email: alexander_suvorov1@hotmail.com