title: Characterization of surface associated antigens of axenic Giardia lamblia trophozoites & their recognition by human sera.
abstract: Two surface associated antigens (GLSA-82 and GLSA-56) of axenically grown G. lamblia trophozoites (PI strain) were affinity purified from its sonic extract. Both GLSA-82 and GLSA-56 were heat labile, sensitive to treatment with pronase, trypsin and were also sodium metaperiodate modifiable as assessed by micro ELISA. Lectin binding studies revealed that GLSA-82 specifically bound concanavalin A and pokeweed mitogen, and had alpha-methyl mannoside and n-acetyl-B-d-glucosamine sugar moieties. However, GLSA-56 selectively bound Ricinus communis agglutinin and phytohaemagglutinin, and had B-d-galactose and n-acetyl-B-d-galastosamine as sugar moieties. Human sera obtained during acute G. lamblia infection recognised GLSA-82 and GLSA-56 antigens. However, the antibody levels to GLSA-82 were significantly lower (P less than 0.05) during active giardiasis infection. Such surface associated antigens may be target of antiparasitic immune responses and thus, may modulate disease processes.
authors.affiliation: Department of Experimental Medicine, Postgraduate Institute of Medical Education & Research, Chandigarh.
authors.forename: K
authors.initials: K
authors.lastname: Kum
authors.forename: R
authors.initials: R
authors.lastname: Khanna
authors.forename: V K
authors.initials: VK
authors.lastname: Vinayak
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000276:immunology*; D000953:Antigens, Protozoan / Q000737:chemistry*; D000954:Antigens, Surface / Q000737:chemistry; D005872:Giardia / Q000276:immunology*; D005873:Giardiasis / Q000276:immunology*; D006801:Humans; D007106:Immune Sera / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D007106:Immune Sera