Efficient production of single-chain fragment variable-based N-terminal trimerbodies in Pichia pastoris

Background: Recombinant antibodies are highly successful in many different pathological conditions and currently enjoy overwhelming recognition of their potential. There are a wide variety of protein expression systems available, but almost all therapeutic antibodies are produced in mammalian cell lines, which mimic human glycosylation. The production of clinical-grade antibodies in mammalian cells is, however, extremely expensive. Compared to mammalian systems, protein production in yeast strains such as Pichia pastoris, is simpler, faster and usually results in higher yields. Results: In this work, a trivalent single-chain fragment variable (scFv)-based N-terminal trimerbody, specific for the human carcinoembryonic antigen (CEA), was expressed in human embryonic kidney 293 cells and in Pichia pastoris. Mammalian-and yeast-produced anti-CEA trimerbody molecules display similar functional and structural properties, yet, the yield of trimerbody expressed in P. pastoris is about 20-fold higher than in human cells. Conclusions: P. pastoris is an efficient expression system for multivalent trimerbody molecules, suitable for their commercial production.