Abstract: Objective To explore the role of T lymphocytes in contact allergic photodermatitis(CAPD). Methods BALB/c female mice were used to establish the model of CAPD induced by chlorpromazine. The mice were injected intraperitoneally with anti-mouse CD4?CD8 mAb. The ear swelling was evaluated at 48h after the challenge. The lymphocytes were counted in H.E section of the swellon ear. The levels of IFN-γ and IL-10 in serum were detected by ELISA. Results Comparing with the negative control, anti-CD4 mAb injected mice had almost the same level of IL-10 (P>0.05), but had a higher level of IFN-γ (P<0.05). The levels of IL-10 and IFN-γ were significantly lower in anti-CD4 mAb injected mice than those in anti-CD8 mAb injected mice (P<0.05). However there was no difference in the ear swelling and mononuclear cell counting between these two groups. Furthermore, the levels of IL-10 and IFN-γ were lower in these two groups than those in the positive control group. There was no difference in the levels of IL-10 and IFN-γ, ear swelling and mononuclear cell counting between combination injection (anti-CD4 plus anti-CD8) group and the negative control group. Conclusions In the model of CAPD induced by chlorpromazine, CD4+Th1 and CD8⁺T lymphocytes up-regulate the reaction by increasing the level of IFN-γ. However, CD4⁺Th2 lymphocytes down-regulate the reaction by increasing the level of IL-10.

Key words: Dermatitis, Photoallergic, Interleukin-10, Interferon type Ⅱ, T-lymphocytes