Studies on the non-specific immunomodulator effects in animals by treatment of Toxoplasma lysate antigens

动物（小鼠、大鼠和牛）经弓形虫裂解物抗原（TLA）预处理后，血液中出现IFN、MAF、MIF、TOXO-GIF等淋巴因子，并表现出较强的非特异性抗性。因此，为了阐明TLA诱导弓形虫抵抗各种感染的防御机制，有必要对弓形虫进行大规模培养。在本基金的研究期间，我们在世界上第一个报告建立了弓形虫悬浮培养30-60天长期大量繁殖的方法，并发现了一种利用微机控制系统从宿主细胞中自动分离有机体的技术。然后，采用TLA检测免疫调节剂对减轻动物巴贝虫、疟原虫或伊氏杆菌感染的临床症状的作用。在我们研究中获得的主要结果中，未使用TLA的对照组小鼠在感染巴贝虫病或疟原虫后没有存活超过2周，而单独使用TLA或与淋巴因子或Obioactin联合使用TLA的小鼠存活率很高。与未经tla处理的牛相比，经tla处理的牛感染蒂勒菌的临床症状和贫血症状极轻。经TLA处理后，小鼠胸腺和脾脏中Thy-1、<Lyt^2>阳性和<Lyt^2>阴性淋巴细胞明显增多，宿主对原虫感染的免疫反应明显增强。

When animals (mice, rats and cattle) were pretreated with Toxoplasma lysate antigens(TLA), lymphokines such as IFN,MAF,MIF,TOXO-GIF appeared in their blood and they showed a strong non-specific resistance. In consequence, in order to clarify the defence mechanisms which can be induced by TLA against various infections, the mass cultivation of Toxoplasma organisms is necessary. Within the research period of this Grant, we established as the lst report in the world, a method of mass and long term propagation of Toxoplasma in suspension cultures for 30-60 days period and also found a technique for separation of the organisms from host cells automatically, using a microcomputer-controlled system. Then, TLA was used to examine the effect of immunomodulator in reducing clinical symptoms of Babesia, Plasmodium or Theileria infection in animals. In the main results obtained in our studies, non of the mice in the non-TLA treated control groups survived for more than 2 weeks after Babesia or Plasmodium infection, however, mice pretreated with TLA alone or together with lymphokiens or Obioactin survived in a high percentage. In the pretreated cattle infected with Theileria, the clinical symptoms and anemia were extremly slight as compared with those of the non-TLA treated cattle. When animals were treated with TLA, Thy-1 and <Lyt^1> positive and <Lyt^2> negative lymphocytes were found to accumulate remarkably in the thymus and spleen and there was a remarkable increase in the immune response of the host to infection with protozoan organisms.