Sj26和Sj23基因转染树突状细胞联合抗血吸虫感染的研究

目的探讨Sj26和Sj23基因转染树突状细胞(DC)联合抗日本血吸虫感染保护性免疫机制。方法BALB/c小鼠耳廓分别注射Sj26和Sj23基因转染DC(A组)、Sj26基因转染DC(B组)、Sj23基因转染DC(C组)、pcDNA3转染DC(D组)、未处理DC(E组)和RPMI-1640(F组),免疫3次,间隔2周,末次免疫后2周,每鼠经皮肤感染40条日本血吸虫尾蚴。ELISA法检测血清特异性IgG抗体、干扰素-γ(IFN-γ)和白细胞介素-4(IL-4)水平,双夹心ELISA法检测脾淋巴细胞经ConA和可溶性虫卵抗原(SEA)刺激后培养上清中IFN-γ和IL-4水平,噻唑蓝(MTT)法检测脾淋巴细胞增殖情况。结果末次免疫后第2周,A组小鼠血清IgG抗体水平显著升高(P<0.001)。血清IL-4的水平,各组免疫前、后无明显变化。血清IFN-γ水平,A组小鼠免疫后明显升高(P<0.01)。经ConA和SEA刺激后,A组小鼠脾淋巴细胞诱生的IFN-γ水平显著增高,而IL-4水平显著降低(与F组比较,P<0.001)。A组小鼠脾淋巴细胞经ConA和SEA刺激后的刺激指数均高于其他各组(与F组比较,P<0.001)。结论体液免疫和细胞免疫共同参与了Sj26和Sj23基因转染DC诱导的保护性免疫作用,其中Th1型免疫应答在抗日本血吸虫感染的保护性免疫中起主要作用。

Studies on mechanism of protective immunity against infection of Schistosoma japonicum induced by Sj26 and Sj23 gene transferred dendritic cells

To explore the mechanism of protective immunity against infection of Schistosoma japonicum induced by Sj26 and Sj23 gene transferred dendritic cells(DC),BALB/c mice were injected into ear pinna three times with Sj26 and Sj23 gene transferred DC(Group A),Sj26 gene transferred DC(Group B),Sj23 gene transferred DC(Group C),pcDNA3 transferred DC(Group D),untreated DC(Group E)and RPMI-1640(Group F),and then challenged with 40 cercariae of S.japonicum per mouse 2 weeks after the last immunization.Sera from mice were used to detect the levels of IgG antibody,IFN-γ and IL-4 by ELISA.The level of IFN-γ and IL-4 in the supernatants of spleen cells stimulated with soluble egg antigen(SEA)and ConA were quantified by sandwich ABC-ELISA.The proliferation of spleen cells were measured with the method of MTT.IgG antibody increased significantly in sera from group A mice at 2 weeks after the last immunization(P<0.001).It was found that the level of IL-4 in sera of each group mice were no significantly different before and after immunization.The levels of IFN-γ in sera of group A mice increased significantly at 2 weeks after the last immunization(P<0.01).In response to ConA and SEA,the level of IFN-γ in spleen cells from group A mice increased significantly,while the IL-4 secretion decreased significantly(compared with group F,P<0.001).The stimulating index of spleen cells from group A mice were higher than those of other groups in response to ConA and SEA(compared with group F,P<0.001).Sj26 and Sj23 gene transferred DC could induce both humoral and cellular immune responses contributed to its protective immunity.It is envident that Sj26 and Sj23 gene transferred DC could induce predominant Th1 type immune response which might play an important role in the protective immunity against infection of S.japonicum.