Production of a new variant of soluble trimer Env of HIV-1 CRF63_02A6 SOSIP.664

Introduction. Obtaining stabilized recombinant HIV-1 Env trimers that have a close to the native conformation is one of the directions in the field of development of vaccines against HIV-1. The aim of the study was to obtain and characterize the stabilized trimer Env of HIV-1 SOSIP.664 based on the circulating genetic variant of the recombinant form CRF63_02A6. Materials and methods. Bioinformatics resources were used to design the trimer Env gene based on the HIV-1 recombinant genetic variant CRF63_02A6. The designed gene was synthesized and cloned as part of an integration plasmid vector. A stable producer of trimer Env was obtained by transfection of the CHO-K1 cell line using the developed plasmid vector. Purification of the protein complex was performed using affinity chromatography and gel filtration. Antigenic properties of trimer Env were studied using immunochemical analysis using broadly neutralizing HIV-1 monoclonal antibodies (bnAbs). Results. A new variant of the stabilized trimer Env of the surface glycoprotein of the recombinant form CRF63_02A6 HIV-1 SOSIP.664 was designed, including additional stabilizing modifications. Based on the CHO-K1 cell line, a stable producer was obtained and a purification protocol for the designed trimer Env was developed. It was found that the trimer Env CRF63_02A6 SOSIP.664 is effectively recognized by bnAbs 2G12, VRC01 and PGT126. Conclusion. The obtained results indicate the prospects for further study of the structural features of the trimer Env CRF63_02A6 SOSIP.664, as well as its immunogenicity and the possibility of using it as a vaccine antigen.