抄録
The effects of diesel exhaust particles (DEP) on Th 1/Th 2 balance and collagen-induced arthritis (CIA) in mice were investigated. Oral administration of neither DEP nor the antigen hen egg lysozyme (HEL) alone produced the Th 1 cytokine IFN-γ and the Th 2 cytokine IL-4. DEP administered orally together with HEL increased the secretion of IFN-γ as well as IL-4 in a dose -related fashion, although IL-4 appeared to be more efficiently secreted in mice given lower doses of DEP. Similar results were obtained when anti-HEL IgG 2 a and IgG 1 antibodies which were Th 1 and Th 2 cell-dependently produced, respectively, were measured. Intraperitoneal injection of HEL alone induced marked Th 2 responses including anti-HEL IgG 1 and IL-4 production, while negligible induction of Th 1 responses including anti-HEL IgG 2 a and IFN-γ. were observed in mice injected with the antigen in the same manner. DEP plus HEL administered intraperitoneally further facilitated the Th 2 responses, but the Th 1 responses remained unchanged. HEL emulsified with complete Freund's adjuvant induced both the Th 1 and Th 2 responses. Furthermore, nasal administration of DEP led to the augmentation of CIA that was associated with anti-type II collagen IgG antibody production. Antigenspecific IgG 2 a and IgG 1 antibodies as well as IFN-γ and IL-4 were also markedly produced. Thus, DEP appear to modulate Th 1/Th 2 balance and have ability to influence autoim-mune diseases.
