A Combination of Antigenic Regions of Toxoplasma gondii Microneme Proteins Induces Protective Immunity against Oral Infection with Parasite Cysts

• Published in: The Journal of infectious diseases Vol. 191; no. 4; pp. 637 - 645
• Main Authors: Beghetto, Elisa, Nielsen, Henrik V., Porto, Paola Del, Buffolano, Wilma, Guglietta, Silvia, Felici, Franco, Petersen, Eskild, Gargano, Nicola
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 15-02-2005; University of Chicago Press; Oxford University Press
• Subjects: Adolescent; Adult; Animals; Antibodies, Protozoan - blood; Antibodies, Protozoan - immunology; Antigens; Antigens, Protozoan - genetics; Antigens, Protozoan - immunology; Biological and medical sciences; Brain - parasitology; Cell Adhesion Molecules - immunology; Child; Child, Preschool; Disease Models, Animal; DNA; Female; Fundamental and applied biological sciences. Psychology; Goods and services tax; Humans; Immunoglobulin G - blood; Infant; Infections; Infectious diseases; Lymphocyte Activation; Male; Medical sciences; Membrane Proteins - immunology; Mice; Mice, Inbred BALB C; Microbiology; Parasites; Plasmids; Pregnancy; Pregnancy Complications, Parasitic - immunology; Protozoan Proteins - immunology; Protozoan Vaccines - immunology; T lymphocytes; T-Lymphocytes - immunology; Toxoplasma - immunology; Toxoplasma gondii; Toxoplasmosis; Toxoplasmosis - immunology; Toxoplasmosis - prevention & control; Toxoplasmosis, Congenital - immunology; Tumors; Vaccination; Vaccines, DNA - immunology; Immunoprotection; Infection; Protozoa; Apicomplexa; Toxoplasma gondii; Microbiology; Cyst; Benign neoplasm; Parasitosis; Protein
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1086/427660

Infection with Toxoplasma gondii causes morbidity and mortality in congenitally infected and immunocompromised individuals. Both humoral and cell-mediated immunity are involved in host resistance to invasion of the parasite. Among putative vaccine candidates, the T. gondii microneme proteins appear to be promising, because they are responsible for the invasion process. The present work focused on studying the immunogenicity of microneme proteins in infected individuals and in a mouse model of chronic toxoplasmosis. We identified 5 distinct antigenic regions within MIC2, MIC4, MIC2-associated protein, and apical membrane antigen 1 gene products, which were recognized by (1) T cells from both adults with acquired infection and children with congenital infection and (2) antibodies from all patients. Finally, we demonstrated that DNA immunization with microneme fragments elicited effective protection in mice (84% reduction in brain-cyst burden), suggesting that a combination of these antigenic regions should be considered in the design of potential vaccines against toxoplasmosis.