IL-10在约氏疟原虫感染过程中免疫调节作用的实验观察

Experimental research on immunoregulatory efficacy of IL-10 in Plasmodium yoelii infection

目的探讨IL-10在疟原虫感染过程中的免疫调节效应。方法用约氏疟原虫感染DBA/2和BALB/c小鼠,取血,制薄血膜,染色后镜检疟原虫,计算红细胞感染率;用ELISA试剂盒检测小鼠血清IFN-γ和IL-10水平。结果DBA/2小鼠于感染后第21d自愈,血清IFN-γ在感染后第3d显著升高(6542pg/ml),之后逐渐下降,至感染后第12d仍高于未感染鼠;血清IL-10于感染后第6d显著升高(248pg/ml),并于感染后第15d达到峰值(980pg/ml)后下降。BALB/c小鼠感染后第6d红细胞感染率达57.5%,并于当日和次日全部死亡;血清IFN-γ仅于感染后第3d出现一过性升高,峰值为2225pg/ml;而IL-10一直处于高水平状态,峰值为432pg/ml。结论小鼠感染约氏疟原虫后过早分泌的高水平IL-10对Th1反应具有明显的抑制效应,而IL-10适时的分泌可能与Th1向Th2反应的转换密切相关。

Objective To explore immunoregulatory efficacy of IL-10 in Plasmodium yoelii infection. Methods DBA/2 and BALB/c mice were infected by i. p. injection of P. yoelii 17XL parasitized RBC. Parasitemia of individual mice was monitored by the microscopic examination on blood smears stained with Giemsa, and the levels of IFN-γ and IL- 10 in sera were detected by ELISA Kit. Results DBA/2 mice spontaneously recovered on day 21 post-infection, the levels of IFN-γ, rose markedly on the 3rd day of post-infection （6 542 pg/ml）, then decreased gradually, but was higher than uninfected mice until the 12th day. The levels of IL-10 in DBA/2 mice begin to rise on day 6 post-infection （248 pg/ ml）, and reached a peak level （980 pg/ml） on day 15 post-infection then declined, Parasitemia of BALB/c mice reached 57.5 % on day 6 post-infection, and then all mice died within two days, The levels of IFN-γ in BALB/c mice rose transi- ently on day 3 post-infection （2 225 pg/ml）, however, the raise of IL-10 levels was prominent from day 3 to day 6 after infection （410-432 pg/ml）, Conclusion Too early and excessively secreted IL-10 can inhibit Thl response of mice infected with P. yoelii 17XL, however, there is a close relationship between timely secretion of IL-10 and switch of Th1 to Th2 response.