目的:研究乙醇工艺对同种异体肌腱的病毒灭活效果.方法:选择伪狂犬病毒(PRV)、猪细小病毒(PPV)、牛腹病毒性腹泻病毒(BVDV)和人类免疫缺陷病毒(HIV-1)为指示病毒,将同种异体肌腱(3个批号)分别负载指示病毒后,用75％乙醇浸泡灭活处理;分别在不同时间点取样,用96孔板的细胞病变法和Karber法测定,计算乙醇工艺处理后同种异体肌腱的病毒残留量(LgTCID50/0.1mL)和计算病毒降低量(log).结果:负载病毒的3个批号样品经过75％乙醇浸泡2h后,PRV、BVDV和HIV-1滴度降低量分别为≥5.971 logs、≥4.400 logs和≥8.000 logs;病毒灭活动力曲线显示:病毒残留量很快降到最低检出限度值.负载PPV的3个批号样品,经75％乙醇浸泡2h后,病毒滴度降低量平均为0.850 logs,浸泡延长至24 h后,病毒滴度降低量平均为1.350 logs,病毒灭活动力曲线显示病毒滴度随时间呈缓慢降低趋势.结论:75％乙醇工艺浸泡处理同种异体肌腱2h,对PRV、BVDV和HIV-1为有效工艺,对PPV无效.

Objective:To screen the neutralizing epitope of enterovirus 71 (EV71) and determine the specific minimum amino acid sequence that triggers immunity for providing a theoretical basis for the development of synthetic peptide vaccines.Methods:EV71 neutralizing antibody-specific binding clones were panned and sequenced using a phage display random 12-peptide library to obtain the key sequences of neutralizing epitopes. A series of peptides containing the key sequences with N-terminal acetylation (AC) and C-terminal linking to Keyhole limpet hemocyanin (KLH) were synthesized. Serum samples were collected after immunizing mice with the modified peptides. Then the immunogenicity of the peptides and the neutralizing activity of serum samples were analyzed by Western blot, ELISA and neutralization test.Results:After three rounds of panning, cloning and sequencing, KQEKDL was identified as the key motif. The serum samples collected from the mice immunized with the modified series of peptides containing key motifs had different degrees of binding ability to EV71 and VP1 protein. The serum samples of mice immunized the synthetic peptide containing only the minimum key motif (AC-KQEKDL-KLH) had the strongest response to the other three peptides and EV71 and the highest neutralizing titer.Conclusions:The EV71 neutralizing epitope was successfully screened using the phage display random peptide library. The key motif of KQEKDL might be the specific minimum amino acid sequence that triggered the immune system. This study provides a theoretical basis for better understanding the immune response mechanism, evaluating the immunogenicity of the antigens and further research and development of polypeptide vaccines.

目的 验证猪源脱细胞结膜基质中病毒灭活工艺的灭活效果.方法 用不同浓度次氯酸钠溶液对猪睾丸(ST)细胞和牛肾(MDBK)细胞行细胞毒性实验;选择猪眼结膜、脱细胞结膜基质各3个批号,用ST细胞和MDBK细胞进行次氯酸钠灭活处理和钴-60(25 kGy)辐照处理后的样品/终止产物的细胞毒性实验;以猪细小病毒(PPV)和牛病毒性腹泻病毒(BVDV)为指示病毒,采用细胞病变法分别测定次氯酸钠工艺和钴-60(25 kGy)辐照工艺对猪脱细胞结膜基质(中间品)病毒灭活效果,并进行细胞盲传实验.结果 次氯酸钠溶液稀释至质量浓度100.00 mg/L(1.0‰)时,ST细胞增殖率大于70％;质量浓度50.00 mg/L(0.5 ‰)次氯酸钠溶液的MDBK细胞增殖率大于70％.1.0‰次氯酸钠溶液处理的猪眼结膜样品在10倍体积稀释后,对ST细胞和MDBK细胞均无抑制作用.脱细胞结膜基质辐照处理,经100倍体积稀释后对MDBK细胞无毒性,经10倍体积稀释后对ST细胞无毒性影响.3个批号猪眼结膜样品经过次氯酸钠溶液处理30 min后,PPV和BVDV的灭活平均降低系数分别为≥4.542 logs和≥4.333 logs;负载PPV病毒样品的盲传3代为阳性,即仍能检测到PPV.3个批号脱细胞结膜基质样品经钴-60辐照后,PPV和BVDV的灭活平均降低系数分别为≥4.792 logs和≥3.667 logs,负载BVDV的3个批号样品盲传结果为阴性,负载PPV病毒的3个批号样品盲传结果为阳性.结论 用次氯酸钠溶液和钴-60辐照两个工艺分别处理脱细胞结膜基质(中间品)后的病毒灭活降低系数累加为:BVDV总降低系数大于8 logs,PPV总降低系数大于9 logs.两个工艺联合可以有效灭活猪源脱细胞结膜基质中污染的PPV和BVDV.