A combination of antigenic regions of Toxoplasma gondii microneme proteins induces protective immunity against oral infection with parasite cysts.
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.
Beghetto
Elisa
E
Kenton Laboratories, Rome, Italy.
Nielsen
Henrik V
HV
Del Porto
Paola
P
Buffolano
Wilma
W
Guglietta
Silvia
S
Felici
Franco
F
Petersen
Eskild
E
Gargano
Nicola
N
D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology*; D001921:Brain / Q000469:parasitology; D015815:Cell Adhesion Molecules / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008213:Lymphocyte Activation; D008297:Male; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology; D015800:Protozoan Proteins / Q000276:immunology; D016052:Protozoan Vaccines / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology* / Q000517:prevention & control*; D014125:Toxoplasmosis, Congenital / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D015815:Cell Adhesion Molecules; D007074:Immunoglobulin G; C408878:MIC2 protein, Toxoplasma gondii; C428323:MIC4 protein, Toxoplasma gondii; D008565:Membrane Proteins; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D019444:Vaccines, DNA