The EhADH112 recombinant polypeptide inhibits cell destruction and liver abscess formation by Entamoeba histolytica trophozoites.
The Entamoeba histolytica EhCPADH complex, formed by a cysteine proteinase (EhCP112) and an adhesin (EhADH112), is involved in adherence, phagocytosis and cytolysis. This makes this complex an attractive candidate as a vaccine against amoebiasis. Here, we produced the recombinant polypeptide EhADH243, which includes the adherence epitope detected by a monoclonal antibody against the EhCPADH complex. EhADH243 was purified, and the effect of the polypeptide on in vitro and in vivo virulence was studied. Antibodies against EhADH243 reacted with the EhCPADH complex and with the recombinant polypeptide. EhADH243 and antibodies against this polypeptide inhibited adherence, phagocytosis and destruction of cell monolayers by live trophozoites, but had little effect on cell monolayer destruction by trophozoite extracts. EhADH243 recognized a 97 kDa protein in the MDCK membrane fraction that could be a putative receptor for E. histolytica trophozoites. Hamsters immunized with EhADH243 developed humoral response against EhCPADH, and animals were partially protected from amoebic liver abscess.
Martínez-López
Carolina
C
Escuela Nacional de Medicina y Homeopatía, IPN, Guillermo Massieu Helguera #239, México, DF, 07320.
Orozco
Esther
E
Sánchez
Tomás
T
García-Pérez
Rosa María
RM
Hernández-Hernández
Fidel
F
Rodríguez
Mario A
MA
D018829:Adhesins, Bacterial / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan / Q000096:biosynthesis; D000953:Antigens, Protozoan / Q000276:immunology*; D003001:Cloning, Molecular; D006224:Cricetinae; D004748:Entamoeba histolytica / Q000276:immunology* / Q000472:pathogenicity / Q000502:physiology; D000939:Epitopes / Q000276:immunology; D004912:Erythrocytes / Q000378:metabolism / Q000502:physiology; D005849:Gerbillinae; D006801:Humans; D008101:Liver Abscess, Amebic / Q000517:prevention & control*; D008969:Molecular Sequence Data; D010587:Phagocytosis / Q000276:immunology / Q000502:physiology; D016052:Protozoan Vaccines; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology / Q000494:pharmacology; D014774:Virulence / Q000276:immunology / Q000502:physiology
D018829:Adhesins, Bacterial; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; C122005:EhADH112 protein, Entamoeba histolytica; D000939:Epitopes; D016052:Protozoan Vaccines; D011994:Recombinant Proteins