Suzuki Y, Conley F K, Remington J S
Department of Immunology and Infectious Diseases, Palo Alto Medical Foundation, California 94301.
Infect Immun. 1990 Sep;58(9):3050-5. doi: 10.1128/iai.58.9.3050-3055.1990.
The effect of exogenous gamma interferon (IFN-gamma) on toxoplasmic encephalitis in a murine model was evaluated. The brains of CBA/Ca mice chronically infected with the ME49 strain of Toxoplasma gondii have a remarkable inflammatory cell infiltrate. Intravenous administration of six doses (5 x 10(5) U each) of recombinant IFN-gamma (rIFN-gamma) resulted in a remarkable decrease in numbers and foci of inflammatory cells in murine brain parenchyma and perivascular areas 1 day after the last injection of IFN-gamma. Immunoperoxidase staining revealed the presence of tachyzoites only on areas of acute focal inflammation, suggesting that the focal inflammation was caused by the proliferation of tachyzoites. The remarkable reduction in number of foci of acute focal inflammation in the brains of the IFN-gamma-treated mice indicates that the treatment resulted in diminished numbers of tachyzoites in the brains of the infected mice. The effect of rIFN-gamma was dose dependent; injection of 5 x 10(5) U every other day for a total of six doses was effective; injection of either 5 x 10(4), 5 x 10(3), or 5 x 10(2) U was not. This therapeutic effect of rIFN-gamma on encephalitis was not present 2 weeks after the last injection of rIFN-gamma. At that time, mice again had severe inflammation in their brains. Toxoplasma antibody production was not affected by treatment with rIFN-gamma. These results offer support for the value of injection of IFN-gamma in the treatment of toxoplasmic encephalitis in immunosuppressed patients, although its effect appears to be transient.
评估了外源性γ干扰素（IFN-γ）对鼠模型弓形虫性脑炎的影响。慢性感染刚地弓形虫ME49株的CBA/Ca小鼠大脑有显著的炎性细胞浸润。静脉注射六剂（每剂5×10⁵单位）重组IFN-γ（rIFN-γ）后，在最后一次注射IFN-γ一天后，鼠脑实质和血管周围区域的炎性细胞数量和病灶显著减少。免疫过氧化物酶染色显示速殖子仅存在于急性局灶性炎症区域，提示局灶性炎症是由速殖子增殖引起的。经IFN-γ治疗的小鼠大脑中急性局灶性炎症病灶数量显著减少，表明该治疗使感染小鼠大脑中的速殖子数量减少。rIFN-γ的作用呈剂量依赖性；每隔一天注射5×10⁵单位，共注射六剂有效；注射5×10⁴、5×10³或5×10²单位则无效。rIFN-γ对脑炎的这种治疗效果在最后一次注射rIFN-γ两周后不存在。那时，小鼠大脑再次出现严重炎症。rIFN-γ治疗不影响弓形虫抗体的产生。这些结果为注射IFN-γ治疗免疫抑制患者的弓形虫性脑炎的价值提供了支持，尽管其效果似乎是短暂的。
