Enhanced UVfemale1 tumor growth in CBF1 mice infected with Schistosoma mansoni due to modulation of Th1-like responses.
Effects of Schistosoma mansoni infection on anti-tumor immunity were examined in CBF1 mice with ultraviolet-induced UVfemale1 fibrosarcoma cells. Although many laboratory established tumor cells had rejection mechanisms independent of CD4(+) T cells, we confirmed that CD4(+) cells had significant roles in rejection of UVfemale1 cells in the syngeneic CBF1 mice. When we prepared two CBF1 mouse groups, S. mansoni-infected and schistosome-free, the former group showed up-regulation of Th2-like response to UVfemale1 cells, whereas the latter group mice showed rather type 1-dominant patterns. Cytotoxic activity against UVfemale1 cells tested in vitro, which was attributed to CD8(+) cells, was significantly weaker in S. mansoni-infected mice compared with infection-free mice. In tumor challenge experiments in vivo, we observed that rapid and complete rejection of UVfemale1 cells required the presence of CD8(+) T cells. Under only CD4-depleted situation, survival of tumor cells in schistosome-free mice was prolonged up to 1 month or more. Under the presence of both CD4(+) and CD8(+) cells, S. mansoni infected mice rejected the challenged UVfemale1 cells as was seen in normal mice. However, when CD8(+) cells were depleted from S. mansoni-infected mice, inoculated UVfemale1 cells grew more rapidly than in infection-free mice. Our results suggest that functionally polarized cytokine patterns in schistosome-infected hosts promote rapid tumor growth.
Department of Medical Zoology, Nagoya City University Medical School, Kawasumi, Mizuhocho, Mizuhoku, Nagoya, 467-8601 Japan.
Ayako
A
Yoshida
Haruhiko
H
Maruyama
Takashi
T
Kumagai
Teruaki
T
Amano
Fumie
F
Kobayashi
Jinyan
J
Wang
Kagemasa
K
Kuribayashi
Nobuo
N
Ohta
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D005354:Fibrosarcoma / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology*; D006084:Graft Rejection / Q000276:immunology*; D007114:Immunization; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D018218:Neoplasms, Fibrous Tissue / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology*; D012550:Schistosoma mansoni / Q000276:immunology; D012555:Schistosomiasis mansoni / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D014185:Transplantation, Isogeneic; D014407:Tumor Cells, Cultured; D014466:Ultraviolet Rays / Q000009:adverse effects
D016207:Cytokines