丙型肝炎病毒结构区抗原联合基因重组体DNA免疫的实验研究

DNA vaccination of the induction of immune responses by codelivery of IL-12 expression vector with hepatitis C structural antigens

目的试图通过对ＤＮＡ免疫的方法进行改进达到增强免疫效率及改变免疫应答类型。方法应用丙型肝炎病毒（ＨＣＶ）结构区基因重组体（ＰＣ和ＰＣＥ１Ｅ２）与白细胞介素（ＩＬ）－１２ｐ３５和ｐ４０编码基因重组体（ＰＩＬ－１２），转染真核细胞并对其表达产物进行检测，并且将ｐＣ、ｐＣＥ１Ｅ２与ｐＩＬ－１２联合免疫ＢＡＬＢ／Ｃ鼠，对其体液免疫和体内、体外细胞免疫应答进行检测。结果所构建的重组体均可在真核细胞内瞬时或稳定表达特异性抗原蛋白。ＰＣ和ＰＣＥ１Ｅ２与ＰＩＬ－１２共免疫时可引起ＢＡＬＢ／Ｃ鼠脾肿大和脾细胞数增多，ＨＣＶ抗原特异性ＣＴＬ反应增强，单独ＰＣ和ＰＣＥ１Ｅ２免疫鼠的ＣＴＬ活力，ｐＣ为（１８．６５±５．７１）％，ｐＣＥ１Ｅ２（２０、０７±１１．１１）％，ＰＣ＋ｐＩＬ－１２为（６０．１１±１７．３７）％，ｐＣＥ１Ｅ２＋ｐＩＬ－１２为（６７．４８±１５．５７）％。但联合ｐＩＬ－１２免疫后抗ＨＣＶ反应减低，免疫后８周平均Ａ值：ＰＣ为０．４１５±０．１２７，ｐＣＥ１Ｅ２为０．３５８±０．０９６，ＰＣ＋ＰＩＬ－１２为０．２１０±０．０８６，ＰＣＥ１Ｅ２＋ｐＩＬ－１２为０．２５８±０．１２５。结论与ＩＬ－１２共免疫可增强ＤＮＡ?

Objective In an attempt to demonstrate the utility of DNA vaccines for the tailoredmethods, the efficacy of immune responses would be enhanced and the types of immune responses shifted.Methods Four recombinant plasmids were constructEd. These included the HCV coding regions for thecore protein(pC) and for the core E1 and E2 together(pCE1E2) IL-12 p35 and p40. These plasmids weretransfected into mammalian cells to test their protein expression and were injected into the quadricepsmuscles of BALB/C mice to measure specific antibodies and cytotoxic T-lymphocyte responses. Rll the recombinant plasmids were shown to express specific antigens in cells transiently and stably.Codelivery of pIL-12 expression cassettes with pC and pCE1E2 in mice resulted in splenomegaly and theincreasing number of the splenocytes. It also resulted in the enhancement of Ag-dependent CTL responses andthe reduction of specific Ab response. The CTL activity were pC=18.65% 5.71%, PCEIE2=20.07% 11.ll%,pC+p1L-12=60. 11% 17.37%, pCE1E2+pIL-12=67.48% 15.57%, respectively. The Anti-HCV activity werepC=0.415 0. 127, pCE1E2=0.358 0.096, pC+pIL-12=0.210 0.086, pCE1E2+pIL-12=0.258 0.125, respetively.Conclusion Codelivery of pIL-12 with plasmid DNA can enhance the efficacy of immune responses andshift the type of immune responses. This work demonstrates the power of DNA delivery in vivo for boththe production of a new g6neration of more effective and targeted vaccines or immuno-therapies as wellas an analytic tool for the molecular dissection of the mechanisms of immune function.