Studies on effector molecules of innate immunity responsible for cytotoxicity to tumor cells.

a .硫脂增强cr3介导的中性粒细胞吞噬作用。硫脂醛是l -选择素的配体，在人中性粒细胞中触发细胞内信号。我们首次发现硫脂能增强cr3介导的人中性粒细胞吞噬作用。我们还观察到，人中性粒细胞中存在未确定的硫fatides受体，并参与增强吞噬作用。b .凋亡细胞和恶性细胞表达的同源补体激活剂。一个;凋亡细胞和原生T细胞都含有一个50 kDa的同源补体激活因子。氨基酸序列分析与延伸因子1α相同。用抗ef -1α.b去除同源补体激活剂活性。我们发现M161Ag在人恶性细胞上表达并诱导同源补体活化。M161Ag与发酵支原体基因产物P48高度同源。结果表明，潜伏感染的发酵分枝杆菌可使人细胞产生M161Ag， M161Ag通过补体激活和细胞因子产生活性，是先天和细胞免疫反应的有效调节剂。

A.Enhancement of CR3-mediated neutrophil phagocytosis by sulfatides.Sulfatides is a ligand for L-selectin and triggers intracellular signals in human neutrophils. We found for the first time the enhancement of CR3-mediated human neutrophil phagocytosis by sulfatides. FcR-mediated phagocytosis was not modified by sulfatides treatment We also observed that unidentified receptor for sulfatides exists on human neutrophils and participates in the enhancement of phagocytosis.B.Homologous complement activators expressed on apoptotic and malignant cells.a ; Apoptotic as well as native T cells were found to contain a homologous complement activator of 50 kDa. Amino acid seqenece analysis was identical to those of elongation factor 1α. The homologous complement activator activity was removed with anti-EF-1α.b. We found a M161Ag, which is expressed on human malignant cells and induces homologous complement activation. cDNA of M161Ag revealed that it is highly homologous to P48, mycoplasma fermentans gene product. It was revealed that latently infected M.fermentans allows human cells to produce M161Ag, which is a potent modulator of innate and cellular immune responses via its complement activating and cytokine-producing activity.