An opposite role is exerted by the acarian Myocoptes musculinus in the outcome of Toxoplasma gondii infection according to the route of the protozoa inoculation.
Infection with Toxoplasma gondii leads to a Th1 immune response. Alternatively, the acarian Myocoptes musculinus induces a disease in BALB/c mice that involves Th2 immune mechanisms. In this study, we investigated whether infestation by M. musculinus induces Th2 immune response in C57BL/6 mice and if this response influences the T. gondii-induced Th1 response when mice are inoculated by intraperitoneal or oral route. The animals were infected with M. musculinus and one month later with T. gondii ME-49 strain and the survival and immune response were monitored. The co-infected animals displayed higher mortality rate and the spleen cells showed a decreased IFN-gamma and elevated IL-4 and IL-5 production. These changes were associated with severe pneumonia and wasting condition. On the other hand, when mice were orally infected with 100 T. gondii cysts, co-infection prolonged the survival rates and ameliorated intestinal lesions in association with a significant drop in IFN-gamma levels in sera. These results indicate the interference of Th2 response induced by M. musculinus in a T. gondii-induced Th1 response. Altogether, these data demonstrate the profound interactions between the immune response induced against unrelated organisms T. gondii and M. musculinus, and suggest that this type of interactions may impact clinical disease.
Welter
Aurea
A
Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia, Campus Umuarama, Av. Pará, 1720, Bloco 4C, Uberlândia, MG 38400-902, Brazil.
Mineo
José Roberto
JR
Silva
Deise Aparecida de Oliveira
DA
Lourenço
Elaine Vicente
EV
Ferro
Eloísa Amália Vieira
EA
Roque-Barreira
Maria Cristina
MC
da Silva
Neide Maria
NM
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D006651:Histocytochemistry; D007136:Immunoglobulins / Q000097:blood; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D015848:Interleukin-5 / Q000096:biosynthesis; D007422:Intestines / Q000469:parasitology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008924:Mite Infestations / Q000150:complications / Q000276:immunology*; D008925:Mites / Q000276:immunology*; D011014:Pneumonia / Q000469:parasitology; D013154:Spleen / Q000276:immunology; D016019:Survival Analysis; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000150:complications / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D015431:Weight Loss
D000913:Antibodies, Protozoan; D007136:Immunoglobulins; D015848:Interleukin-5; D015847:Interleukin-4; D007371:Interferon-gamma