嗜酸性粒细胞介导的ADCC效应在旋毛虫感染免疫中的作用研究

The effects of eosinophil-mediated ADCC on immunization against trichinellosis

目的通过对小鼠总IgE、特异性IgE及依赖IgE的嗜酸性粒细胞(Eos)介导的ADCC效应的动态观察,进一步探讨嗜酸性粒细胞在旋毛虫病免疫中的作用。方法采用双抗体夹心ELISA法,分别检测感染旋毛虫后7、14、21、28、35、60d小鼠外周血中总IgE水平,用间接ELISA法测定特异性IgE水平;分别在96孔细胞培养板的板孔中加入感染旋毛虫小鼠外周血提取的嗜酸性粒细胞。感染鼠血清及感染鼠的旋毛虫肌幼虫与含10%灭活小牛血清的RPMI-1640培养液,37℃条件下培养,分别在12、24、48h显微镜下观察小鼠Eos对旋毛虫肌幼虫的影响。结果实验组较对照组总IgE水平增高,在感染后14、21d达到高峰(P<0.01),之后呈逐渐下降;特异性IgE阳性率在感染后14和21d为88.9%,对照组阳性率为0,差异有统计学意义(P<0.01)。在体外培养的条件下,单纯Eos对旋毛虫肌幼虫无杀伤作用,在免疫血清参与下,Eos对幼虫的杀伤作用明显增强;灭活IgE和补体后,Eos的杀伤作用明显减弱,与单纯Eos组比较肌幼虫死亡率差异无统计学意义(P>0.05)。结论 Eos对旋毛虫肌幼虫杀伤的过程需要免疫血清的参与,免疫血清中介导上述效应的物质为IgE和补体。

Objective This paper discusses the role of eosinophils（Eos） in immune response in mice with trichinosis.This was done by dynamic observation of total IgE,specific IgE,and IgE-dependent ADCC activity triggered by eosinophils.Methods Total and specific IgE were measured 7,14,21,28,35,and 60 days after mice were infected with Trichinella spiralis by means of a double-antibody sandwich enzyme-linked immunosorbent assay（ELISA） and indirect ELISA.Eos from blood of mice infected with Trichinella spiralis,muscle stage larvae,infected serum,and PRMI-1640 containing 10% inactivated calf serum were placed in wells of 96-well plates and incubated at 37 ℃.The effect of Eos was determined by observing the activity of the larvae at 12 h,24 h,and 48 h with microscope.Results The experimental group had markedly higher total IgE on day l4 and day 21 compared to the control group（P〈0.01）;after three weeks,the level of the total IgE began to drop.Samples tested positive for specific IgE on day l4 and day 21 at a rate of 88.9%（P〈0.01）.The cytotoxicity of Eos was not observed during in vitro culturing.In the presence of immune serum,Eos were markedly cytotoxic to larvae.The cytotoxic activity of Eos decreased markedly after inactivation of IgE and complement.Conclusion Immune serum is required for Eos to be cytotoxic to muscle stage larvae,IgE and complement are critical mediators of Eos-mediated cytotoxicity to muscle stage larvae.