Structural Analysis and Mechanisms of Action of Various Inflammatory Cytokines

1. 炎性细胞因子的纯化和结构分析(a)巨噬细胞趋化因子：我们纯化了一种具有较强巨噬细胞趋化活性的低分子量肽，并阐明了其氨基酸序列。此外，我们合成了该肽，并观察到合成的肽也具有很强的巨噬细胞趋化活性。(b)巨噬细胞迁移抑制因子（Macrophage migration inhibitory factor， MIF）：从人T细胞杂杂瘤培养上清中纯化两种MIF。我们对这两个因子的部分氨基酸序列进行了分析，发现这两个因子是新的淋巴因子。(c)巨噬细胞活性活化因子（MAF-C）：从人T细胞杂交瘤培养上清中纯化MAF-C。通过加入抗IL-2抗体，纯化因子的巨噬细胞活化活性被完全抑制，提示MAF-C实际上是IL-2或与IL-2的抗原相关物质。然后，我们分析重组IL-2.2对巨噬细胞的激活作用。肿瘤坏死因子的作用机制我们发现活化的巨噬细胞在体内杀死肿瘤细胞，并在体外对肿瘤坏死因子产生抗性。因此，我们分析了活化的巨噬细胞的杀瘤活性机制，发现活化的巨噬细胞依赖精氨酸syn的存在产生NO，与肿瘤坏死因子协同作用于肿瘤细胞。

1. Purification and structural analysis of inflammatory cytokines(a) Macrophage chemotactic factor : We purified a low molecular weight peptide having strong macrophage chemotactic activity and elucidated its amino acid sequence. Furthermore, we synthesized this peptide and observed that the synthetic peptide also has strong macrophage chemotactic activity.(b) Macrophage migration inhibitory factor (MIF) : We purified two kinds of MIF form the culture supernatant of human T cell hybridomas. We elucidated partial amino acid sequences of these two factors and found that these factors are novel lymphokines.(c) Macrophage activation factor for tumoricidal activity (MAF-C) : We purified MAF-C from the culture supernatant of human T cell hybridomas. Macrophage activating activity of the purified factor was completely inhibited by the addition of anti-IL-2 antibody, suggesting that MAF-C is actually IL-2 or an antigenically related substance with IL-2. Then, we analyzed macrophage activating of recombinant IL-2.2. Mechanism of action of tumor necrosis factorWe found that activated macrophages kill tumor cells in vivo which are resistant to tumor necrosis factor in vitro. Therefore, we analyzed the mechanism of tumoricidal activity of activated macrophages, and we found that NO produced by activated macrophages depending on the presence of arginine syn ergistically acts on tumor cells with tumor necrosis factor.