ANTIBODIES TO THE SERINE RICH ENTAMOEBA-HISTOLYTICA PROTEIN (SREHP) PREVENT AMEBIC LIVER-ABSCESS IN SEVERE COMBINED IMMUNODEFICIENT (SCID) MICE

Amoebic liver abscess caused by Entamoeba histolytica is a major cause of morbidity and mortality worldwide. We used mice with severe combin ed immunodeficiency (SCID mice) to study the role of antibody in prote ction from amoebic liver abscess, and to identify protective antigens of E. histolytica. Antisera to recombinant versions of two major surfa ce antigens off. histolytica, the serine rich E. histolytica protein ( SREHP) and the 170 kDa adhesin were used in this study. We found that 100% of SCID mice passively immunized with antiserum to the recombinan t SREHP molecule were protected from developing amoebic liver abscess after intrahepatic challenge with virulent E. histolytica trophozoites . In contrast, preimmune serum, antiserum to a portion of the 170 kDa adhesin, and antiserum to the trpE fusion partner of SREHP did not pro tect SCID mice from amoebic liver abscess. Out study demonstrates that antibodies to a recombinant version of the amoebic SREHP molecule can protect against amoebic liver abscess, and suggest the recombinant SR EHP molecule should be considered as a possible vaccine candidate to p revent amoebic liver abscess.