title: Immunolocalization of an enterotoxic glycoprotein exoantigen on the secretory organelles of Cryptosporidium parvum sporozoites.
abstract: In this study, the fine ultrastructures of the secretory organelles of C. parvum sporozoites were demonstrated using transmission electron microscopy (TEM). Meanwhile, a previously identified enterotoxic 18-20 kDa copro-antigen (18-20 kDa CCA), associated with cryptosporidiosis in both human and calves, was isolated and immunolocalized on C. parvum sporozoites. Using immunoelectron microscopy and anti-18-20 kDa monospecific antibody demonstrated marked existence of the 18-20 kDa CCA on the apical organelles and at the trilaminar pellicles. An anterior extrusion-of this protein was demonstrated around the excysted and released sporozoites. However, non excysted sporozoites did not show this protein. Affinity blotting, with biotinylated jacalin, demonstrated the O-linked oligosaccharide moiety of this protein. The potential role of this protein in the host cell invasion and/or gliding motility remains unelucidated. However, its enterotoxicity, location and secretory nature suggest that it may be a target for neutralization or invasion inhibition of Cryptosporidium.
authors.affiliation: Microbiology and Parasitology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt. Khel666@hotmail.com
authors.forename: K A
authors.initials: KA
authors.lastname: el-Shewy
authors.forename: R A
authors.initials: RA
authors.lastname: Eid
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology* / Q000302:isolation & purification / Q000633:toxicity; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology; D003457:Cryptosporidiosis / Q000469:parasitology; D016785:Cryptosporidium parvum / Q000276:immunology* / Q000648:ultrastructure*; D005243:Feces / Q000469:parasitology; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D016253:Microscopy, Immunoelectron; D015388:Organelles / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D006023:Glycoproteins