IMMUNOGENICITY OF THE RECOMBINANT SERINE RICH ENTAMOEBA-HISTOLYTICA PROTEIN (SREHP) AMEBIASIS VACCINE IN THE AFRICAN-GREEN MONKEY

We report the first study in non-human primates of the safety and immu nogenicity of a recombinant vaccine designed to prevent amebic liver a bscess. In a pilot study, a recombinant vaccine containing the serine rich Entamoeba histolytica protein (SREHP) attached to a maltose bindi ng protein (SREHP/MBP), which has been shown to be effective in preven ting amebic liver abscess in rodent models of infection was used to im munize two African Green Monkeys. Vaccination with SREHP/MBP resulted in no systemic side-effects. The monkeys receiving the SREHP/MBP prote in developed antibodies that recognized the recombinant SREHP/MBP mole cule, the native SREHP protein, and the surface of amebic trophozoites . Antiserum from SREHP/MBP-vaccinated monkeys could block the adhesion off. histolytica trophozoites to mammalian cells, a feature that may correlate with vaccine efficacy. Attempts to produce amebic liver absc ess in naive African Green Monkeys by direct hepatic inoculation with virulent E. histolytica trophozoites was not successful, suggesting th is species is probably not suitable for vaccine efficacy studies.