Attempts to eliminate immunological Suppression associated with bacterial infections.

各种细菌产物对宿主的免疫抵抗力具有积极或消极的影响。在瘤型麻风患者中观察到深刻的免疫抑制，在其血清中可以检测到麻风分枝杆菌的独特糖脂，酚糖脂（PGL-1）。我们从麻风分枝杆菌感染的犰狳组织中纯化了PGL-1，并通过NMR确定了制备物。在小鼠体内注射胶束形式的PGL-1诱导细胞介导的免疫的显着抑制：抑制Con A诱导的T细胞增殖和抑制同种异体杀伤T细胞的产生。在正常脾培养物上加入PGL-1也导致ConA反应的抑制和同种异体杀伤T细胞的产生。PGL-1的这种抑制作用可被正常腹腔巨噬细胞吞噬所完全消除，提示PGL-1的抑制作用是由于巨噬细胞的损伤所致。这种糖脂在胶束形式下对免疫反应具有类似的作用。然而，含有GaGM的脂质体增强了细胞毒性T细胞、NK细胞的产生和抗体依赖性细胞毒性（ADCC）的活性。这些结果表明糖脂的作用受其呈递给宿主的形式的影响。

Various bacterial products have positive or negative effects on the immunological resistance of the host. Profound immunological suppression is observed in patients with lepromatous leprosy, in whose sera a unique glycolipid to Mycobacterium leprae, phenolic glycolipid (PGL-1), can be detected. We purified PGL-1 from the infected tissues of armadillos with Mycobacterium leprae, and ascertained the preparations by NMR. In vivo injection of the PGL-1 in a micell form into mice induced remarkable suppression in cell-mediated immunity: The inhibition of Con A-induced T cell proliferation and the inhibition of generation of allogenic killer T cells. Addition of the PGL-1 on the normal splenic cultures also resulted the suppression of Con A responses and generation of allogenic killer T cells. These suppression by PGL-1 were completely abrogated by the supplementaion with normal peritoneal macrophages, suggesting that the inhibition by PGL-1 was due to the injuries in macrophages.We also isolated a mycolic acid-containing glycolipid (GaGM) derived from Gordona aurantiaca, an acid-fast bacterium closely related with Mycobacterium. This glycolipid had simillar effects on the immunological responses in a micell form. However, liposomes containing GaGM enhanced generation of cytotoxic t cells, NK cells, and activity of antibody dependent cytotoxicity (ADCC). These results suggest that effects of gycolipids were affected by their forms for presentaion to the host.