Tehran University Medical Journal

Background: Infeliximab is a form of chimeric antibody which neutralizes the most important inflammatory cytokine, TNF-a, in inflammatory disorders. The aim of current study was to pilot expression of chimeric infliximab in Chinese Hamster ovary (CHO) cells.

Methods: In this research study, pVITRO2-neo-mcs vector that consist of infliximab light chain and heavy chain was used to transform into the E.coli by CaCl2 method. The plasmid was then purified and transfected to cultured CHO cells by Lipofectamine 2000® (Invitrogen GmbH, Germany). Transfected cells were selected upon G-418 treatment after 2 weeks and the level of expression, based on standard curve, was measured using IgG ELISA kit after 48 hours for each clone. High level expressed clone was then cultured in roller bottles and recombinant chimeric product was purified by protein A affinity chromatography. The purity of the product was analyzed by 10% gel SDS-PAGE from eluted samples. The efficacy of the purification was analyzed by ELISA before and after purification step. This article is a master's student thesis from February 2015 to August 2016 in pharmaceutical technology development center, Tehran University of Medical Sciences, Tehran, Iran.

Results: The purified plasmid was analyzed on 2% agarose gel. After selective pressure of G-418, 10 stable transfect clones were assessed for infliximab secretion by IgG ELISA kit at 450 nm. The maximum and minimum expression which detected by ELISA were 23 ng/ml and 6 ng/ml, respectively. The band width of infliximab fraction during purification procedure was observed at 0.7-0.8 min. The efficiency of the purification by ELISA was 70%. On SDS-PAGE analysis, two bands, 25 and 50 kDa, respect to light and heavy chains of Infliximab, was confirmed the expression of recombinant protein.

Conclusion: In the current study, the construct for infliximab monoclonal antibody production was designed using genetic engineering techniques and the expression was confirmed by conventional molecular biology methods. The high yield production was carried out in semi-industrial scale using roller bottles with a 70 percentage of purification efficiency.