During Trypanosoma cruzi infection CD1d-restricted NK T cells limit parasitemia and augment the antibody response to a glycophosphoinositol-modified surface protein.
Trypanosoma cruzi is a protozoan parasite that chronically infects many mammalian species and in humans causes Chagas' disease, a chronic inflammatory disease. The parasite expresses glycophosphoinositol (GPI), which potently stimulates interleukin 12 (IL-12) production. During T. cruzi infection IL-12, and possibly GPI, might stimulate NK T cells to affect the protective and chronic inflammatory responses. Here we report that during T. cruzi infection CD1d-restricted NK T cells are stimulated as NK T-cell-deficient mice have greater parasitemia. Furthermore, during T. cruzi infection the percentages of NK T cells in the liver and spleen become decreased for prolonged periods of time, and in vitro stimulation of NK T cells derived from livers of chronically infected mice, compared to uninfected mice, results in increased gamma interferon and IL-4 secretion. Moreover, in NK T-cell-deficient mice the chronic-phase antibody response to a GPI-modified surface protein is decreased. These results indicate that, during the acute infection, NK T cells limit parasitemia and that, during the chronic phase, NK T cells augment the antibody response. Thus, during T. cruzi infection the quality of an individual's NK T-cell response can affect the level of parasitemia and parasite tissue burden, the intensity of the chronic inflammatory responses, and possibly the outcome of Chagas' disease.
Duthie
Malcolm S
MS
Department of Pediatrics, Chiba University, Chiba, Japan.
Wleklinski-Lee
Monika
M
Smith
Sherilyn
S
Nakayama
Toshinori
T
Taniguchi
Masaru
M
Kahn
Stuart J
SJ
D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000276:immunology*; D018949:Antigens, CD1 / Q000276:immunology*; D055610:Antigens, CD1d; D002455:Cell Division; D002478:Cells, Cultured; D014355:Chagas Disease / Q000276:immunology* / Q000469:parasitology; D002908:Chronic Disease; D004195:Disease Models, Animal; D005260:Female; D005699:Galactosylceramides / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D008099:Liver / Q000166:cytology / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018512:Parasitemia / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D014349:Trypanosoma cruzi / Q000276:immunology; D014643:Variant Surface Glycoproteins, Trypanosoma / Q000276:immunology*
D000913:Antibodies, Protozoan; D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human; D005699:Galactosylceramides; D014643:Variant Surface Glycoproteins, Trypanosoma; D015847:Interleukin-4; D007371:Interferon-gamma