Construction and Expression of a Mouse-human Chimeric Antibody against Hepatitis E Virus
A neutralizing mouse anti-HEV monoclonal antibody(McAb),designated as 8C11,has previously been produced and characterized by our laboratory.We reported here the construction and the expression of mouse-human chimeric antibody derived from the McAb.cDNAs encoding variable regions of heavy and light chains were isolated from 8C11 cells by RT-PCR,and introduced into mammalian expression vectors pcDNA3.1/Hygro and pcDNA3.1(+)containing cDNA of human gamma 1 and kappa constant regions,respectively.The vectors were cotransfected into CHO cells.The result of RT-PCR showed that the introduced genes for chimeric heavy and light chains were transcribed.Indirect ELISA and Western blot indicated that the peptides were assembled correctly to form native IgG molecule, which could be secreted outside the cells.The expressed chimeric antibody held the binding specificity of its original McAb to HEV and enhanced the binding activity of 8H3 to antigen.The chimeric antibody described here is expected to be less immunogenic and thus more suitable for possible antibody therapy for hepatitis E.