Engineering and expression of bibody and tribody constructs in mammalian cells and in the yeast Pichia pastoris.

Bibodies and tribodies are therapeutic antibody derivatives with sizes of approximately 75 and 100 kDa, respectively. This makes them smaller than full-size monoclonal antibodies, leading to better tissue penetration. Compared to the smaller scFv and Fab fragments, the bi- and tribody formats have the additional advantage of a slower renal clearance. However, the cost-effective and efficient production of these and other antibody derivatives is crucial for their further success as therapeutics. Here, we describe the construction and initial transient production in mammalian cells of bibodies and tribodies, followed by their stable production in Pichia pastoris. The purification of the antibody derivatives from the yeast supernatant is also explained.