expression of a novel hiv-1 gag-pol-env-nef-rev multi-epitope construct in escherichia coli

Introduction: recombinant subunit vaccines have been explored against various human pathogens, however, developing an effective therapeutic toward human immunodeficiency virus (hiv) infection has been challenging. so far, several recombinant hiv-1 antigens have been produced and examined for activation of desired immune responses. this study aimed to express an hiv-1 multiepitope protein as an antigen candidate to develop a vaccine. methods: in this study, the codon-optimized encoding sequence of the designed multi-epitope construct (gag-pol-env-nef-rev) was synthesized and subcloned into the pet-24a (+) expression vector. then, expression of the target antigen was evaluated in e. coli bl21 (de3) and rosetta strains under different conditions (temperature, optical density/ od600, isopropyl β-d-1-thiogalactopyranoside (iptg) concentration, and time). finally, the expression of the gag-pol-env-nef-rev multi-epitope protein was confirmed using sds-page and western blot analysis. results: the highly conserved and immunodominant t-cell epitopes of hiv-1 gag, pol, env, nef, and rev proteins were used to prepare a novel gag-pol-env-nef-rev multi-epitope construct. the gag-pol-env-nef-rev gene was successfully sub-cloned in pet-24a (+) vector and subsequently expressed in bl21 (de3) e. coli strain under optimized conditions (1 mm iptg, 16 h post-induction, od 600= 0.6, and 37ºc). a clear band of ~ 35 kda was detected by western blotting using an anti-his antibody, indicating the successful expression of our target multi-epitope protein. conclusion: expression of the recombinant hiv-1 multi-epitope protein was optimized in a bacterial system. the expressed protein will be purified to use as a multi-epitope protein vaccine candidate in the future.