Romero-Piffiguer M D, Ferro M E, Riera C M
Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
Autoimmunity. 1990;6(3):161-72. doi: 10.3109/08916939009041036.
In the present work we studied the influence that an infection with Toxoplasma gondii in thymus proximity produces on the suppression of autoimmune response to autoantigen of rat male accessory glands (RAG). The suppression was achieved injecting syngeneic animals with low doses of autoantigen of RAG previous to the immunization with chemically modified rat male accessory glands (MRAG). Rats were infected in thymus proximity with 3 x 10(3) trophozoites of T. gondii before or after to be suppressed. Controls were rats only infected or only suppressed. The delayed hypersensitivity response against MRAG, (DTH test), was significantly potentiated in rats only infected and in the animals suppressed before the infection (p less than 0.001). The suppression was not inhibited in the animals suppressed after infection. The suppression of humoral response against MRAG studied by ELISA and passive hemagglutination test was prevented in rats infected before as well as in rats infected after the induction of suppression (p less than 0.001). Decrease of CD4+ CD8+ and Ox18+ (class I MHC antigen) and increase of CD4+ CD8- and CD4- CD8- thymocytes was observed in the rats where the DTH response was potentiated. These results indicate that the infection with T. gondii in thymus proximity was able to inhibit the suppression of response to autoantigen of RAG producing selective impairment in thymic suppressor influence.
在本研究中，我们探究了胸腺附近感染刚地弓形虫对大鼠雄性附属性腺自身抗原（RAG）自身免疫反应抑制的影响。通过在化学修饰的大鼠雄性附属性腺（MRAG）免疫前给同基因动物注射低剂量的RAG自身抗原，实现了这种抑制。在抑制之前或之后，将大鼠在胸腺附近感染3×10³个刚地弓形虫滋养体。对照组为仅感染或仅被抑制的大鼠。仅感染的大鼠以及在感染前被抑制的动物中，针对MRAG的迟发型超敏反应（DTH试验）显著增强（p<0.001）。感染后被抑制的动物中，抑制作用未被抑制。通过ELISA和被动血凝试验研究的针对MRAG的体液反应抑制，在抑制诱导前感染的大鼠以及抑制诱导后感染的大鼠中均被阻止（p<0.001）。在DTH反应增强的大鼠中，观察到CD4⁺CD8⁺和Ox18⁺（I类MHC抗原）减少，以及CD4⁺CD8⁻和CD4⁻CD8⁻胸腺细胞增加。这些结果表明，胸腺附近感染刚地弓形虫能够抑制对RAG自身抗原反应的抑制，在胸腺抑制性影响方面产生选择性损伤。
