CCL20对HBV基因疫苗的免疫增强作用

Enhancement of CCL20 to the antigen specific immune responses induced by gene immunization with HBsAg conding gene

CCL20为CC家族的趋化因子,对未成熟DC和T细胞具有较强的正向趋化作用。HBsAg是乙肝病毒中具有保护作用的结构抗原。以HBsAg为目的抗原进行基因免疫可诱导HBV特异性免疫应答。为进一步增强基因疫苗的免疫效果,研究中,应用基因重组技术,构建CCL20和HBsAg的真核表达载体,将重组体用肌肉注射方式免疫C57BL/6小鼠,通过ELISA方法检测C57BL/6小鼠的抗-HBs抗体水平、淋巴细胞增殖试验检测抗原特异性Th活性、FACS检测CTL效应。结果显示,用CCL20/HBsAg真核表达质粒共注射免疫后,100%小鼠能在第4、6周检测到抗-HBs抗体,CCL20可显著增强HBsAg基因疫苗诱导的体液免疫应答;Th活性和CTL效应检测也显示,CCL20增强了HBsAg诱导的特异性细胞免疫反应。这将为新型乙肝疫苗的分子设计和研制提供新的理论与实践依据。

It was well-evidenced that a gene vaccine harboring surface antigen of hepatitis B virus （HBsAg） could successfully induce both specific humoral and cellular immune responses, but the efficiency of these immune responses still remained to be improved. In the present study, CCL20, a chemokine of CC chemokine family was introduced into the gene vaccine and the enhancement of HBsAg specific immune responses was observed. CCL20 and HBsAg eukaryotic expression recombinant were constructed by using pcDNA3 as the vector. In vitro expression of HBsAg and CCL20 was detected by Western blotting.C57BL/6 mice were co immunized with pHBsAg plus pCCL20, while either pHBsAg or pCCL20 alone was used as the controis. Anti HBs antibody, the antigen-specific lymphoproliferation and CTL activity were analyzed by ELISA, lymphoproliferation assay and FACS, respectively. Results showed that both humoral and cellular immune responses against HBsAg was enhanced by co-injection of pCCL20, indicating the potential of CCL20 in the design of novel prophylactic and therapeutic vaccines against HBV infection.