Application of a 2A-peptide system for polycistronic human IgG production in Leishmania tarentolae

Monoclonal antibodies are commonly expressed using mammalian cell lines due to their required post-translational modifications. However, this process can become costly and requires investment in specialized equipment and facilities. The use of eukaryotic cell Leishmania tarentolae offers a cost-effective alternative while still allowing N-linked glycosylation to occur. The focus of this study explores the use of L. tarentolae as a platform for expressing a monoclonal IgG antibody against the long-chain neurotoxin (LNTX) from the venom of the Monocled Cobra, Naja kaouthia. The monoclonal antibody was isolated from a human naïve phage display library and expressed as single-chain fragment variable (scFv) in Escherichia coli with good specificity against the LNTX of Naja kaouthia. The scFv was then converted to the scFv-Fc format and full-length IgG for expression in L. tarentolae. The IgG expression was achieved using a 2A peptide-based bicistronic vector system with good expression yield. The expressed IgG demonstrated homogeneity in size and minimal degradation. Therefore, L. tarentolae can be considered a possible alternative platform for the expression of human scFv-Fc and IgG antibodies.