目的:观察乙型肝炎病毒(HBV)S区DNA疫苗pCR3.1-S诱导BALB/C小鼠(H-2~d)的特异性免疫应答,及其对稳定表达HBsAg的小鼠肥大细胞瘤细胞P815(P815-HBV-S)成瘤性的影响。方法:肌肉注射DNA疫苗;背部皮下接种P815-HBV-S细胞,观察成瘤情况;ELISA法检测小鼠血清抗HBs;4h~(51)Cr释放法检测小鼠脾细胞CTL活性。结果:pCR3.1-S体外可表达HBsAg;小鼠接种该疫苗后血清450nm A值为0.38,强化免疫后达0.87;pCR3.1-S组CTL细胞杀伤活性为51.1％,对照组为20.5％(P<0.01)。接种P815-HBV-S细胞后对照组成瘤率100％,pCR3.1-S小鼠成瘤率为16.7％,对照组小鼠6周后全部死亡;pER3.1-S组6周后存活率为87.5％。结论:HBV S区DNA疫苗具有良好的免疫原性,能够诱导小鼠产生特异性体液免疫和细胞免疫应答,对体内HBV感染具有预防及治疗作用。 Objective: To observe the specific immune response of BALB / C mice (H-2 ~ d) induced by DNA vaccine pCR3.1-S in hepatitis B virus (HBV) region and its effect on the mast cell tumor Effect of cell P815 (P815-HBV-S) on tumorigenicity. Methods: P815-HBV-S cells were inoculated subcutaneously in the back and tumorigenicity was observed. Serum anti-HBs were detected by ELISA and CTL activity of spleen cells were detected by 4h ~ (51) Cr release assay. Results: The expression of HBsAg in pCR3.1-S cells in vitro was 0.38 at 450 nm and 0.87 after immunization. The CTL cell killing activity in pCR3.1-S group was 51.1% and in control group was 20.5% (P <0.01). After the P815-HBV-S cells were inoculated, the rate of tumor formation was 100%, the rate of pCR3.1-S mice was 16.7%, and the control mice all died after 6 weeks. The survival rate of pER3.1-S group after 6 weeks 87.5%. Conclusion: DNA vaccine of HBV S region has good immunogenicity, can induce specific humoral and cellular immune responses in mice, and has a preventive and therapeutic effect on HBV infection in vivo.