Radioprotective effect of ADF, ATL-derived factor

我们一直在研究生物反应调节剂（BRM）对宿主防御系统的影响，以应对包括X射线照射在内的应激。ADF，ATL衍生因子，已被证明具有氧化还原电位，如硫氧还蛋白和其他各种生物活性。在本研究中，在小鼠系统中检查ADF对骨髓死亡的辐射保护作用。当小鼠在暴露于致死剂量的X射线后立即用重组人ADF治疗时，它们逃脱了急性骨髓死亡，存活了30多天。需要多次给予ADF以显示辐射防护作用。ADF注射防止了由X射线照射引起的NK（自然杀伤）细胞活性的降低。而ADF对外周血中粒细胞、血小板和红细胞的数量及其集落形成单位无影响。还原活性较低的转基因ADF效果较差。这些结果表明，ADF可能通过激活宿主对感染的防御机制而产生辐射防护作用。

We have been studying the effects of biological response modifiers (BRM) on the host defense system against stress including X-ray irradiation. ADF, ATL-derived factor, has been shown to have redox potential such as thioredoxin and other various biological activities. In the present study the radioprotective effect of ADF on bone marrow death was examined in the mouse system. When mice were treated with recombinant human ADF immediately after exposure to lethal doses of X-rays, they escaped from acute bone marrow death and survived more than 30 days. Multiple administration of ADF was required for the manifestation of the radioprotective effect. ADF injection prevented the decrease in NK (natural killer) cell activity induced by X-ray irradiation. However, the numbers of granulocytes, platelets and erythrocytes in the peripheral blood and their colony forming units were not affected by ADF. The genetically modified ADF with less reducing activity was less effective. These results indicate that ADF may produce the radioprotective effect through activation of host defense against infection.