【摘要】 目的　研究分子佐剂C3d能否增强人绒毛膜促性腺激素 (hCG) βDNA疫苗的免疫原性 ,并转变Th1/Th2型免疫应答模式。方法　抽提纯化pcDNA3、pcDNA3 hCGβ、pcDNA3 hCGβ C3d3、pCMV4 hCGβ C3d34种质粒。将 12只 6周龄BALB/c雌性小鼠分为 12组 ,A1～ 3组各 6只以pcDNA3免疫 ,作为空白对照组 ;B1～ 3组各 6只以pcDNA3hCGβ免疫 ,作为阴性对照组 ;C1～ 3组各 6只以pcDNA3 hCGβ C3d3免疫 ,作为实验 1组 ;D1～ 3组各 5只以pCMV4 hCGβ C3d3免疫 ,作为实验 2组。免疫前 1周 ,于小鼠左后腿肌肉注射 0 2 5 %普鲁卡因 0 1ml。 1周后 ,在相同部位分别肌注前述 4种质粒 ,剂量分别为 :5pmol(A1～D1组 )、10pmol(A2～D2组 )、2 0pmol(A3～D3组 )。 3周后 ,再次给予相同剂量质粒加强免疫。于第 2次免疫后 3周 ,处死小鼠。用ELISA法测定外周血抗hCGβ抗体效价和经hCG抗原体外刺激脾细胞培养上清中Th1型 (IL 2、INF γ、TNF α) /Th2型 (IL 4、IL 10 )细胞因子分泌水平。结果　C3d分子佐剂能明显提高抗hCGβ抗体滴度。当免疫剂量为 2 0pmol时 ,与B3组比较 ,C3组抗hCG抗体最大效价达到 1∶4 5 0 ,提高了 9倍。D3组抗hCG抗体最大效价达到 1∶12 15 0 ,提高了 2 4 3倍。D3组与C3组相比较 ,抗hCG抗体水平提高了 2 7倍。受更多还原

【Abstract】 Objective To testify the effect of C3d molecular adjuvant on the immunogenicity of human chorionic gonadotropin β (hCGβ) DNA vaccination as well as the mode of immune response. Methods BALB/c mice aged 6 weeks were immunized intramuscularly two times at an interval of 3 weeks with by the plasmid pcDNA3 (A1～3 groups), pcDNA3-hCGβ (B1～3 groups), pcDNA3-hCGβ-C3d3 (C1～3 groups), or pCMV4-hCGβ-C3d3 (D1～3 groups), at dosage of 5 pmol, 10 pmol, and 20pmol, respectively. Three weeks after the second vaccination the animals were killed, specimens of their peripheral blood were extracted to determine the anti-hCGβ antibody titer by indirect ELISA. Their spleen cells were harvested and stimulated in vitro by hCG antigen for 24 hours. The Th1/Th2 cytokines in the culture supernatant were determined by ELISA. Results At the dosage of 20 pmol, C3d molecular adjuvant significantly enhanced the anti-hCGβ antibody titer. The utmost anti-hCGβ antibody titer of C3 group was 1∶450, 9 times higher than that of B3 group, and the utmost anti-hCGβ antibody titer of D3 group was 1∶12 150, 243 times higher than that of B3 group. Stimulated in vitro by 5 000 IU hCGβ antigen, the splenetic cells of the C3 and D3 immunization group produced significantly lower IL-2, INF-γ and TNF-α than those of the B3 immunization group (P<0.01 or P<0.05). The IL-4 level of the C3 group was higher than that of the B3 group while the IL-10 level of the D3 group was significantly higher than that of the B3 group (P<0.01). Conclusions The C3d molecular adjuvant increases significantly the hCGβ immunogenicity of hCGβ DNA vaccination; meanwhile decreases the secretion of Th1 cytokines(IL-2, INF-γ, and TNF-α), and increases the expression of Th2 cytokines(IL-4 and IL-10)in response to hCG antigen. So C3d changes the anti-hCG immune response from Th1 type to Th2 type.更多还原