747. Evaluating Sm-p80 Vaccine Cross-Species Protection against Schistosoma haematobium in Hamsters
Session: Poster Abstract Session: Vaccines: New and Novel
Thursday, October 27, 2016
Room: Poster Hall
Posters
  • IDSA Poster Revised.pdf (1.2 MB)
  • Background:

    Schistosomiasis remains a major health problem affecting over 230 million people worldwide. Despite control efforts, clear limitations, such as re-infection rates and drug resistance, necessitate the development of a vaccine for long term protection against the disease. Schistosoma mansoni antigen, Sm-p80, is a protein involved in host immune evasion by schistosomes due to its role in parasite membrane biogenesis. Previous Sm-p80-based vaccination studies have consistently shown high levels of protection against S. mansoni infections in animal models. We therefore hypothesize that induction of specific host immune responses through Sm-p80-based vaccination would provide the opportunity to control urinary schistosomiasis caused by S. haematobium infection. In this study, we evaluated the cross-species protective efficacy of Sm-p80 vaccine against S. haematobium infections in hamsters.

    Methods:

    DNA vaccine was prepared by cloning the coding sequence of Sm-p80 into VR1020 plasmid. Sm-p80/VR1020 plasmid was isolated and then purified on Sepharose column. Recombinant protein vaccine was generated by cloning the coding sequence for Sm-p80 gene in pCold II vector and expressed in Escherichia coli followed by affinity chromatography. Two groups of hamsters were immunized with either delivery vehicle only (control group) or DNA/protein vaccine (vaccinated group) and subsequently challenged with 200 S. haematobium cercariae. Sm-p80-specific antibody titers were measured by ELISA. Vaccine efficacy was determined by worm reduction and tissue egg load.

    Results:

    Immunization with Sm-p80 vaccine elicited a balanced Th1/Th2 response as shown by the significant production of Sm-p80-specific IgG antibodies in the immunized animals when compared to controls. Significant reduction in worm burden (26.9%) was observed in vaccinated hamsters when compared to the controls. However, there was no reduction in tissue egg loads between the two groups.

    Conclusion:

    The results presented in this study demonstrated that immunizations with Sm-p80 vaccine conferred cross-species protection against S. haematobium infections thereby reinforcing Sm-p80 as a promising vaccine that could provide relief for both intestinal and urinary schistosomiasis.

    Laura Johnson, .1, Afzal Siddiqui, PhD2, Adebayo Molehin, PhD2, Weidong Zhang, PhD2 and Juan Rojo, BS3, (1)School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, (2)Center for Tropical Medicine and Infectious Diseases, Texas Tech University Health Sciences Center, Lubbock, TX, (3)Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX

    Disclosures:

    L. Johnson, None

    A. Siddiqui, None

    A. Molehin, None

    W. Zhang, None

    J. Rojo, None

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