Optimization of cancer immunotherapy by controlling immune cell trafficking and biodistribution

An immunosurveillance system for tumor-associated antigens (TAAs) plays an important role in the elimination of cancer cells during the initial stage. Although cancer immunotherapy targeting TAAs has progressed steadily with the development of various vaccine strategies, excellent therapeutic efficacy, as evidenced by marked tumor regression and complete response, has not been reported in a clinical setting to date. To improve the therapeutic effects of cancer immunotherapy, we are attempting to establish an innovative concept, the "cell delivery system," capable of better controlling the trafficking and biodistribution of immune cells by applying chemokine-chemokine receptor coupling, which regulates leukocytic migration and infiltration of local sites in the living body. This review introduces our approaches that employ an Arg-Gly-Asp (RGD) fiber-mutant adenovirus vector encoding the chemokine or chemokine receptor gene in cancer immunotherapy.