title: Purified anti-CD3 × anti-HER2 bispecific antibody potentiates cytokine-induced killer cells of poor spontaneous cytotoxicity against breast cancer cells.
abstract: BACKGROUND
  Chemical crosslinking is the most straightforward method to produce bispecific antibodies (BsAb) for arming ex vivo activated cytotoxic T lymphocytes. However, heterogeneous polymers are produced by chemical crosslinking. Currently, it is not known under what circumstances or to what extent further purification is needed.
  
  
  RESULTS
  In this study, we purified Traut's Reagent-Sulfo-SMCC crosslinked anti-CD3 × anti-HER2 by size-exclusion column chromatography and compared the capacity of the crude and the purified forms of the BsAb in enhancing cytokine-induced killer (CIK) cell-mediated cytotoxicity in vitro. We found that the purified BsAb assisted CIK cells more efficiently than the crude form only when the spontaneous cytotoxicity of the CIK cells was relatively low; otherwise, the two forms performed almost identically.
  
  
  CONCLUSIONS
  For the CIK cells of low spontaneous cytotoxicity, purified BsAb is a more powerful substitute for crude BsAb in enhancing their killing efficacy. However, that purification of BsAb is not necessary for robust CIK cells. This phenomenon also corroborates that CIK-mediated cytotoxicity is highly dependent on cell contact.
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Dongdan Santiao 5 #, Dongcheng district, Beijing, 100005 China.
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: He
authors.affiliation: Affiliated Hospital of Hebei University, No.212, Yu Hua East Rd, Nan Shi District, Baoding, Hebei 071000 China.
authors.forename: Haisong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Dongdan Santiao 5 #, Dongcheng district, Beijing, 100005 China.
authors.forename: Youzhao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: JiangSu Laitai Medical Biotechnology Co., LTD, 3F, Building4, No.879 Zhongjiang Road, Shanghai, China.
authors.forename: Hong Hoi
authors.initials: HH
authors.lastname: Ting
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Dongdan Santiao 5 #, Dongcheng district, Beijing, 100005 China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Yu
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Dongdan Santiao 5 #, Dongcheng district, Beijing, 100005 China.
authors.forename: Xuetao
authors.initials: X
authors.lastname: Cao
authors.affiliation: National Key Laboratory of Medical Molecular Biology & Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Dongdan Santiao 5 #, Dongcheng district, Beijing, 100005 China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ge
keywords: Bispecific antibody; CIK cells; Chemical crosslinking; Protein purification