Antibody-IL2 fusion proteins for tumor targeting

Increasing insight into the misbalance and poor activity of tumor infiltrating immune cells raised interest to activate and improve an antitumor immune response by accumulating IL2 in the tumor tissue. IL2 can be targeted as part of an antibody-cytokine fusion protein to the tumor tissue by a single chain fragment of variable regions (scFv) antibody recognizing a tumor-associated antigen. IL2 can moreover be combined with IL12 in a dual cytokine fusion protein, which simultaneously targets both cooperating cytokines to the tumor in order to improve the activation of both T cells and innate immune cells. We here describe in detail the construction, expression, and functional testing of antibody-IL2 fusion proteins and provide a protocol to determine the biodistribution of such proteins in animal models.