Taming interleukin-12: Engineering of bispecific antibody-based IL-12 mimetics with biased agonism capacities.

In this work, we have generated bispecific interleukin (IL)-12 surrogate agonists based on camelid-derived single-domain antibodies (sdAbs) targeting the IL-12 receptor (IL-12R) subunits IL-12Rβ1 and IL-12Rβ2. Following immunization and antibody display-based paratope isolation, respective sdAbs were combinatorially reformatted into a monovalent bispecific architecture by grafting resulting paratopes onto the hinge region of a heterodimeric Fc region. Functional characterization using NK-92 cells enabled the identification of multiple different sdAb-based bispecifics displaying divergent IL-12R agonism capacities as analyzed by STAT4 phosphorylation.