title: Entamoeba histolytica and E. dispar Calreticulin: inhibition of classical complement pathway and differences in the level of expression in amoebic liver abscess.
abstract: The role of calreticulin (CRT) in host-parasite interactions has recently become an important area of research. Information about the functions of calreticulin and its relevance to the physiology of Entamoeba parasites is limited. The present work demonstrates that CRT of both pathogenic E. histolytica and nonpathogenic E. dispar species specifically interacted with human C1q inhibiting the activation of the classical complement pathway. Using recombinant EhCRT protein, we demonstrate that CRT interaction site and human C1q is located at the N-terminal region of EhCRT. The immunofluorescence and confocal microscopy experiments show that CRT and human C1q colocalize in the cytoplasmic vesicles and near to the surface membrane of previously permeabilized trophozoites or are incubated with normal human serum which is known to destroy trophozoites. In the presence of peripheral mononuclear blood cells, the distribution of EhCRT and C1q is clearly over the surface membrane of trophozoites. Nevertheless, the level of expression of CRT in situ in lesions of amoebic liver abscess (ALA) in the hamster model is different in both Entamoeba species; this molecule is expressed in higher levels in E. histolytica than in E. dispar. This result suggests that EhCRT may modulate some functions during the early moments of the host-parasite relationship.
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ximénez
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Enrique
authors.initials: E
authors.lastname: González
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Miriam E
authors.initials: ME
authors.lastname: Nieves
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV, 07360 México, DF, Mexico.
authors.forename: Angélica
authors.initials: A
authors.lastname: Silva-Olivares
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV, 07360 México, DF, Mexico.
authors.forename: Mineko
authors.initials: M
authors.lastname: Shibayama
authors.affiliation: Departamento de Infectómica y Patogénesis Molecular, CINVESTAV, 07360 México, DF, Mexico.
authors.forename: Silvia
authors.initials: S
authors.lastname: Galindo-Gómez
authors.affiliation: Departamento de Biología Celular, CINVESTAV, 07360 México, DF, Mexico.
authors.forename: Jaime
authors.initials: J
authors.lastname: Escobar-Herrera
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Ma Del Carmen
authors.initials: Mdel C
authors.lastname: García de León
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Morán
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Alicia
authors.initials: A
authors.lastname: Valadez
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Liliana
authors.initials: L
authors.lastname: Rojas
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Eric G
authors.initials: EG
authors.lastname: Hernández
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: Oswaldo
authors.initials: O
authors.lastname: Partida
authors.affiliation: Departamento de Medicina Experimental, Facultad de Medicina, UNAM, Dr. Balmis 148, Colonia Doctores, 06726 México, DF, Mexico.
authors.forename: René
authors.initials: R
authors.lastname: Cerritos
mesh_terms: D037282:Calreticulin / Q000276:immunology*; D003171:Complement Pathway, Classical / Q000276:immunology*; D004748:Entamoeba histolytica / Q000276:immunology* / Q000472:pathogenicity*; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D008101:Liver Abscess, Amebic / Q000276:immunology* / Q000469:parasitology*
chemical_list: D037282:Calreticulin