Design of in silico Trifunctional Antibody (hIgG1-FC: mouse-antiHER2× human-B7.1) Gene Cassettes and Expression Vectors: The Stage Prior to Production

Abstract

The specific gene cassettes and expression vectors for tri-functional antibody (hIgG1-FC: mouse-antiHER2× human-B7.1) were designed in silico. The in silico tri-functional antibody has been derived from human IgG1, human B7.1, and mouse antiHER2 antibody. The variable domains of IgG1 framework were substituted by Cha21 (mouseantiHER2 scFV) VH-VL, and B7.1 IgV-like domains. The domain data of human IgG1 heavy and light chain-constant regions, human B7.1 IgV-like, and cha21 variable regions were obtained from UniprtoKB and PDB databases. The 3D structure of domains was trimmed and modeled by pyMol software. To ensure the presence of antigen binding residues, complementarity determining regions, and framework regions in variable domain structure, the researchers analyzed the cha21-VH and VL nucleotide sequences using Paratome and IMGT softwares, respectively. In this study, two in silico expression vectors were designed. The vector forms were ready in silico to be synthesized and transfected into CHO cells in order to be developed; the cells expressing the chimeric tri-functional antibody which enables the eradication of HER2-expressing cancer cells using apoptotic induction, T-cell activation and accessory cell activation by antiHER2, B7.1, and Fc domains, respectively.