Abstract
It is widely accepted that a cancer develops when cancer cells escape from the control of the immune system and that harnessing the immune defences in order to reactivate endogenous anti-tumor T cells could be a therapeutic option for full and durable responses.Type I interferon is known for its potent antitumor activity in experimental mouse tumors. Furthermore, it has been shown to be a key cytokine necessary for the efficacy of many anticancer agents targeting not only cancer cells (ionising radiations, cytostatic chemicals, mAbs…) but also the immune system (vaccination, CAR-T cells…). However, its use is no longer considered by the clinician owing to the side effects experienced by the patients. To address this concern, a highly promising technology allowing the design of cell-specific targeted interferon molecules has been developed and the objective of our present work is to generate and pre-clinically evaluate lead compounds. For this, a number of research frontiers must be tackled, these include to answer to the fundamental questions 'where' and 'when' interferon must act in order to exert its antitumor activity either alone or in combination with the above-mentioned therapeutic strategies.The question 'when' is important because it is highly suspected that the relative timing of interferon action and TCR stimulation determines whether the effect of interferon is immunostimulant or immunosuppressive. The question 'where' is evident since it determines the choice of the targeting moiety of the engineered interferons. We know that the action of interferon on dendritic cells is necessary for its antitumor activity but is it sufficient? Is an action on T cells also mandatory? Is an interferon action on tumor cells or stroma cells necessary for attracting effector immune cells?