目的探讨马抗SARSCoV中和性抗体是否对SARSCoV感染有防治作用。方法用SARSCoV(BJ01株)免疫马匹,从免疫马血清中制备IgGs及其F(ab’)2片段。通过细胞病变法(CPE)、MTT法和空斑形成实验(PFU)等方法,在体外培养的VeroE6细胞中检测F(ab’)2片段对SARSCoV感染的预防性和治疗性作用。再在Balb/c小鼠体内模型中,用CPE法和定量RTPCR方法检测该抗体的保护性效应。结果CPE、MTT和PFU三种方法证实来自三匹马的血清F(ab’)2的中和滴度均达到1∶1600以上。体内实验证实,50μg的F(ab’)2片段可以完全中和1×104TCID50SARSCoV。结论马抗SARSCoV抗体在体内外均能有效地中和SARSCoV和预防其感染宿主细胞,为马抗体将来在大的灵长类动物或人体内进行实验提供实验依据。 Objective To investigate whether MA neutralizing antibodies to SARSCoV could prevent or treat SARSCoV infection. Methods IgGs and their F (ab ’) 2 fragments were prepared from immunized horse serum by immunizing horses with SARSCoV (strain BJ01). The preventive and therapeutic effects of F (ab ’) 2 fragments on SARSCoV infection were tested in Vero E6 cells cultured in vitro by methods such as cytopathic effect (CPE), MTT assay and plaque formation assay (PFU). Then in the Balb / c mouse model, the protective effect of the antibody was tested by the CPE method and the quantitative RTPCR method. Results CPE, MTT and PFU confirmed that the neutralizing titers of serum F (ab ’) 2 from three horses reached above 1: 1600. In vivo experiments confirmed that 50 μg of F (ab ’) 2 fragment completely neutralized 1 × 104 TCID50SARSCoV. Conclusion The anti-SARSCoV antibody can effectively neutralize SARSCoV and prevent the host cells from infecting both in vitro and in vivo. It provides an experimental basis for the future experiments of horse antibodies in large primate or human.