Involvement of inflammatory cytokines in a delayed-type hypersensitivity reaction

We previously reported the amino acid sequence of the human macrophage chemotactic factor with a molecular weight of 1000 (MCF-1) was WLGREDGSE. In this study we examined the roles of MCF-1 and tumor necrosis factor (TNF) in a guinea pig delayed-type hypersensitivity (DTH) reaction. When macrophage chemotactic activity (MCA) in a skin extract was subjected to gel filtration, only the activity with a molecular weight of 1000 was significantly inhibited by anti-human MCF-1 mAb (7-3 mAb). Both MCA and TNF activity were detected in skin extracts from DTH inflammation sites where the specific antigen was injected. Both activities were produced at the early DTH reaction stage. In contrast, MCF-1 was produced at the late DTH reaction stage. The erythema was suppressed significantly either by anti-guinea pig TNF Ab or by 7-3 mAb, suggesting the roles of these two cytokines in a DTH reaction.