Effects of interlinker sequences on the biological properties of bispecific single-chain antibodies

Chinese Science Bulletin (Impact Factor: 1.37). 01/2003; 48(21):2277-2283. DOI: 10.1360/03wc0168

ABSTRACT Single-chain bispecific antibody (scBsAb) is one of the promising genetic engineering antibody formats for clinical application.
But the effects of interlinker sequences on the biological properties of bispecific single-chain antibodies have not been
studied in detail. Three interlinker sequences were designed and synthesized, and denominated as Fc, HSA, 205C′, respectively.
Universal vectors with these different interlinker sequences for scBsAb expression in E. coli were constructed. A model scBsAb based on a reshaped single-chain antibody (scFv) against human CD3 and a scFv directed against
human ovarian carcinoma were generated and expressed in E. coli. The results of SDS-PAGE and Western blot showed that the different interlinker sequences did not affect the expression level
of scBsAb. However, as demonstrated by ELISA and pharmacokinetics studies performed in mice, scBsAbs with different interlinker
sequences had difference in the antigen-binding activities and terminal half-life time (T
1÷2β) in vivo, the interlinker HSA could remarkably prolong the retention time of scBsAb in blood. These results indicated that the peptide
sequence of interlinker could affect important biological properties of scBsAb, such as antigen-binding properties and stability
in vivo. So, selection of an appropriate interlinker sequence is very important for scBsAb construction. Optimal interlinker can
bring scBsAb biological properties more suitable for clinical application.

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