Chen Xing-Zhi, Yang Xiao-Di, Yang Wen, Chen Yong, Liu Li-Li, Shen Ji-Long, Sun Xin
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2013 Apr;31(2):99-103.
To observe the immune response induced by ROP2 protein of Toxoplasma gondii with cimetidine in mice.
Eighty BALB/c mice were randomly divided into 4 groups: PBS (group A), ROP2 protein (group B), ROP2 protein-Freund's adjuvant (group C) and ROP2 protein-cimetidine (group D). Mice were immunized with PBS, ROP2 protein, ROP2 protein and Freund's adjuvant, ROP2 protein and cimetidine [200 mg/(kg x d)] by subcutaneous injection three times at an interval of 2 weeks, respectively. Experimental mice were immunized with 100 microg ROP2 proteins, which were diluted to a final volume of 200 microl in PBS. On day 13, 27 and 41 after immunization, mice sera were collected for determination of antibody IgG and cytokine IFN-gamma by ELISA. Two weeks after the final immunization, T cells subpopulation was detected by flow cytometry and splenocyte proliferation activity was determined with CCK-8. Another 12 immunized mice in each group were intraperitoneally challenged with 5 x 10(4) tachyzoites of T. gondii and the survival time was observed.
Two weeks after final immunization, compared with groups A [(659.750 +/- 239.962) pg/ml] and B [(872.750 +/- 197.011) pg/ml], the level of IFN-gamma significantly increased in groups C [(1 600.750 +/- 480.680) pg/ml] and D [(1494.375 +/- 451.655) pg/ml] (P < 0.01). Similarly, compared with groups A (0.636 +/- 0.108) and B (0.871 +/- 0.089), the level of IgG was also higher in groups C (1.068 +/- 0.111) and D (1.046 +/- 0.147) (P < 0.01). The proliferation of splenocytes rose in group C (0.831 +/- 0.130) after immunization, and similarly in group D (0.762 +/- 0.089), and were both significantly higher than that of groups A (0.504 +/- 0.078) and B (0.592 +/- 0.160) (P < 0.01). Moreover, ratio of CD4+/CD8+ in groups C (0.831 +/- 0.130) and D (0.762 +/- 0.089) were higher than that of groups A (0.504 +/- 0.078) and B (0.592 +/- 0.160) (P < 0.05). After challenge with violent virulence strain of tachyzoites, the median survival time of mice in groups A, B, C, and D were 96, 108, 132, and 132 h, respectively. The mean survival time of mice in groups C and D were longer than that of groups A and B (P < 0.05). There was no significant difference in 5 parameters between C and D: the level of IFN-gamma and IgG, CD4+/CD8+ ratio, splenocyte proliferation, and survival time of mice (P > 0.05).
Cimetidine can enhance the humoral and cellular immune response induced by ROP2 protein.
观察西咪替丁对刚地弓形虫ROP2蛋白诱导的小鼠免疫反应的影响。
将80只BALB/c小鼠随机分为4组：PBS组（A组）、ROP2蛋白组（B组）、ROP2蛋白-弗氏佐剂组（C组）和ROP2蛋白-西咪替丁组（D组）。分别于第0、2、4周皮下注射PBS、ROP2蛋白、ROP2蛋白与弗氏佐剂、ROP2蛋白与西咪替丁[200 mg/(kg·d)]，每组20只。实验小鼠用100 μg ROP2蛋白免疫，用PBS稀释至最终体积200 μl。在免疫后第13、27和41天，采集小鼠血清，用ELISA法检测抗体IgG和细胞因子IFN-γ。末次免疫后2周，用流式细胞术检测T细胞亚群，用CCK-8法检测脾细胞增殖活性。每组另取12只免疫小鼠腹腔注射5×10⁴个刚地弓形虫速殖子，观察存活时间。
末次免疫后2周，与A组[(659.750±239.962) pg/ml]和B组[(872.750±197.011) pg/ml]相比，C组[(1 600.750±480.680) pg/ml]和D组[(1494.375±451.655) pg/ml] IFN-γ水平显著升高（P<0.01）。同样，与A组(0.636±0.108)和B组(0.871±0.089)相比，C组(1.068±0.111)和D组(1.046±0.147) IgG水平也升高（P<0.01）。免疫后C组(0.831±0.130)和D组(0.762±0.089)脾细胞增殖均升高，均显著高于A组(0.504±0.078)和B组(0.592±0.160)（P<0.01）。此外，C组(0.831±0.130)和D组(0.762±0.089) CD4⁺/CD8⁺比值高于A组(0.504±0.078)和B组(0.592±0.160)（P<0.05）。用强毒株速殖子攻击后，A、B、C、D组小鼠的中位存活时间分别为96、108、132和132 h。C组和D组小鼠的平均存活时间长于A组和B组（P<0.05）。C组和D组在IFN-γ和IgG水平、CD4⁺/CD8⁺比值、脾细胞增殖和小鼠存活时间5个参数上无显著差异（P>0.05）。
西咪替丁可增强ROP2蛋白诱导的体液免疫和细胞免疫反应。
