补体C3对大肠杆菌疫苗的免疫增强作用

The immune enhancement of the C3 to the Escherichia coli vaccine

从SPF鸡血清中分离纯化C3,用戊二醛将其与大肠杆菌抗原连接,免疫注射SPF鸡;对照组鸡免疫注射弗氏完全佐剂大肠杆菌疫苗。分别在免疫后的第2、3、4、5、6、7、8、9周采血,用ELISA方法测定血清中的抗体含量,同时测定血清中总补体活性。结果表明,免疫后3周,弗氏佐剂大肠杆菌疫苗诱导鸡体产生的抗体效价高于C3佐剂疫苗组,但至第4周,弗氏佐剂疫苗组的抗体水平达到高峰(OD值=0.270±0.004),然后迅速下降,到第9周降至0.200±0.005,而C3疫苗组鸡免疫后的抗体水平持续上升,从免疫后第2周的0.098±0.003上升到第8周的0.275±0.002。证明C3能够促进免疫记忆细胞的产生,并能够使细菌抗原给予免疫细胞持续稳定的刺激,从而使鸡体维持高水平抗体的时间延长。研究结果为研制有效的家禽细菌性疫苗提供了理论依据。

C3b was separated and purified from the SPF chicken serum. It was linked with E. coli antigen by the glutaral. 11 days aged SPF chicken were immunized by the complex antigen and the chickens of control group were immunised by the FCA-E. coli antigen . They were boosted at the age of 18 day. The immune response was monitored by an enzyme-linked immunosorbent assay（ELISA） for anti-E, coli anitibody. The ELISA results indicated that during the early several weeks, IgG titers elicited by FCA （FCA-E. coil）were higher than those elicited by C3 （C3b-E. coli ）, but decreased rapidly after a peak around the end of 4th week from being immunized. Chickens immunized with C3b always gave increased response, and the IgG titers were equal to that of FCA at the end of 5th week from being immunized and then higher and higher than that of FCA. Thus the adjuvant effect of C3b is different from that of FCA, it could induce production of memory cell and make the antigens stimulate immune cells consistently and stably.