title: Excreted/secreted glycoproteins of G. intestinalis play an essential role in the antibody response.
abstract: In the present work, glycoproteins in the excretory/secretory products of G. intestinalis were identified and the reactivity in serum of immunized mice with these molecules was evaluated by western blotting before and after chemical treatment or enzymatic deglycosylation. Glycoproteins of 58 and 63 kDa were revealed in E/S products after periodic acid-Schiff (PAS) stain. Studies of carbohydrate specificity using digoxigenin-labeled lectins, revealed the presence of O-glycans and N-glycans. Chemical treatment of excretory/secretory products with sodium meta-periodate or enzymatic deglycosylation with N-glycosidase F reduced the reactivity in serum for proteins of 36, 58 and 63 kDa, respectively. These results show the presence of glycoproteins in E/S products of G. intestinalis and suggest that the antibody response is directed against glycoepitopes. The expression of carbohydrate moieties in the E/S-G. intestinalis may play an essential role in the antibody response and may be a target for serodiagnosis or immune intervention in human giardiasis.
authors.affiliation: Laboratory of Immunopathology, Institute of Biomedicine, Faculty of Medicine, Central University of Venezuela, Caracas, Venezuela. jcjimenez488@hotmail.com
authors.forename: J C
authors.initials: JC
authors.lastname: Jiménez
authors.forename: W
authors.initials: W
authors.lastname: Morelle
authors.forename: J-C
authors.initials: JC
authors.lastname: Michalsky
authors.forename: E
authors.initials: E
authors.lastname: Dei-Cas
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000953:Antigens, Protozoan; D005260:Female; D016829:Giardia lamblia / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology* / Q000378:metabolism; D007279:Injections, Subcutaneous; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000276:immunology* / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D006023:Glycoproteins; D015800:Protozoan Proteins