Immunogenicity and protective efficacy of heparan sulphate binding proteins of Entamoeba histolytica in a guinea pig model of intestinal amoebiasis

• Published in: Experimental parasitology 2013-11, Vol.135 (3), p.486-496
• Main Authors: Kaur, Upninder, Khurana, Sumeeta, Saikia, Uma Nahar, Dubey, M.L.
• Format: Article
• Language: English
• Subjects: amebiasis; Animals; antibodies; Antibodies, Protozoan - biosynthesis; Antibodies, Protozoan - blood; antibody formation; binding proteins; Carrier Proteins - immunology; Carrier Proteins - metabolism; cecum; Cecum - parasitology; Cecum - pathology; Disease Models, Animal; Dysentery, Amebic - immunology; Dysentery, Amebic - prevention & control; Entamoeba histolytica; Entamoeba histolytica - chemistry; Entamoeba histolytica - immunology; Guinea pig model amoebiasis; Guinea Pigs; Heparan Sulphate Binding Proteins; Heparitin Sulfate - metabolism; histopathology; Immunity, Cellular; immunoglobulin A; immunoglobulin G; immunoglobulin M; Immunoglobulins - biosynthesis; Immunoglobulins - blood; in vitro studies; lymphocytes; Lymphocytes - immunology; Male; monocytes; Monocytes - immunology; morbidity; mortality; parasitology; Protozoan Proteins - immunology; Protozoan Proteins - metabolism; Protozoan Vaccines - standards; Spleen - cytology; Spleen - immunology; splenocytes; trophozoites; Vaccination; vaccines
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2013.08.011

•Heparan Sulphate Binding Proteins (HSBPs) of E. histolytica were immunogenic.•HSBPs elicited both humoral and cellular immune response in guinea pig model.•Vaccination with HSBPs limits pathology after challenge infection.•Histopathological studies also supported the protective role. Entamoeba histolytica infection is associated with considerable morbidity and mortality in the form of intestinal and extraintestinal amoebiasis. No vaccine is yet available for amoebiasis. Heparan Sulphate Binding Proteins (HSBPs) from E. histolytica were evaluated for immunogenicity and protective efficacy in a Guinea pig model. Animals were immunized subcutaneously with 30μg of HSBP by three weekly inoculations. The immunogenicity of HSBP was determined by antibody response (IgG, IgM and IgA), splenocyte proliferation assay and in vitro direct amoebicidal assay with splenic lymphocytes and monocytes from vaccinated and control animals. The efficacy of the vaccine was evaluated by challenge infection to vaccinated and control animals by intra-caecal inoculation of E. histolytica trophozoites and comparing gross and histopathological findings in caeca of these animals. HSBP was found to induce specific anti-amoebic response as seen by specific antibody production and direct amoebicidal activity of splenocytes. The vaccine also showed partial protection against challenge infection in vaccinated animals as shown by mild/absent lesions and histopathological findings.