Generation of CD8+ suppressor T cells by protoscoleces of Echinococcus multilocularis in vitro.
Addition of protoscoleces (PSC) of Echinococcus multiocularis suppressed proliferative responses in spleen cells stimulated with concanavalin A (Con A) on day 3 of culture. The suppression was not observed in the spleen cell population depleted of CD8+ cells but observed in the population depleted of CD4+ cells, suggesting the involvement of the CD8+ T cells in the apparent suppression. Indeed, flow cytometry analysis revealed that the proportion of CD8+ cells markedly increased in the Con A cultures containing PSC. Furthermore, when spleen cells were co-cultured with PSC alone, marked increase in the proportion of CD8+ cells as well as B220+ cells was observed. Addition of these increasing CD8+ cells suppressed the proliferative responses of fresh spleen cells stimulated with Con A. These findings suggest that the low responsiveness of spleen cells to Con A on day 3 of culture in the presence of PSC is attributable to an active suppressor mechanism including CD8+ T-suppressor cells generated by stimulation with PSC.
Kizaki
T
T
Hokkaido Institute of Public Health, Hokkaido University, Japan.
Ishige
M
M
Bingyan
W
W
Day
N K
NK
Good
R A
RA
Onoé
K
K
D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000032:analysis*; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D003208:Concanavalin A / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D004446:Echinococcus / Q000276:immunology*; D005260:Female; D007108:Immune Tolerance / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000947:Antigens, Helminth; D016827:CD8 Antigens; D003208:Concanavalin A