CD22 antibody and application thereof

The bispecific antibody targeting CD22 and CD19 and the chimeric antigen receptor provided by the invention overcome the technical effect defect of double-target CAR in the prior art, aim at recurrence or ineffectiveness caused by an escape mechanism and the like of B-ALL in the CD19 CAR-T treatment period in the prior art, reduce the tumor recurrence rate after CAR-T treatment, have high CAR transduction efficiency, are suitable for industrial production, and have wide application prospects. Experiments prove that the CAR-T cell capable of simultaneously targeting the bispecific sites of CD19 and CD22 has a very good anti-tumor effect. 本发明提供的靶向CD22和CD19的双特异性抗体及嵌合抗原受体克服了现有技术中双靶点CAR的技术效果缺陷，是针对现有技术中CD19CAR-T治疗期间因B-ALL的逃避机制等而产生复发或无效，并且降低CAR-T治疗后肿瘤复发率，且CAR转导效率高，适合工业化生产，经试验验证可同时靶向CD19和CD22的双特异性位点的CAR-T细胞具有很好的抗肿瘤效果。