Engineering and characterisation of a b aculovirus-expressed m ouse/ human chimeric antibody against transferrin receptor on the surface of human tumour cells


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Xin Shen, Gui-bin Hu, Guan-xin Shen

Hubei University of Chinese Medicine, Wuhan City, China

Abstract

Transferrin receptor (TfR) has been explored as a target for antibody-based therapy of cancer. In the previous study we reported a murine anti-TfR monoclonal antibody 7579 had good anti-tumour activities in vitro. In an attempt to reduce its immunogenicity and enhance its ability to recruit immune effector mechanism in vivo, we herein developed its chimera in the baculovirus/insect cell expression system based on the mating-assisted genetically integrated cloning (MAGIC) strategy. The chimeric light and heavy chains, containing human IgG1 constant regions, were correctly processed and assembled in insect cells, and then secreted into the mediums as heterodimeric H2L2 immunoglobulins. Furthermore, analyses of antigen-binding assay and competitive binding assay indicated that the chimeric antibody possessed specificity and affinity similar to that of its parental murine antibody. Results of the ADCC and CDC assay verified that the chimeric antibody could efficiently mediate ADCC and CDC against TfR-overexpressing tumour cells.

These results suggested that the baculovirus-expressed chimeric anti-TfR IgG1 could be a promising candidate for cancer therapy. Meanwhile, the MAGIC strategy, facilitating the rapid generation of chimeric mAbs, showed potential as one of the efficient strategies for antibody-engneering.