Evidence That Sunscreens Prevent UV Radiation-Induced Immunosuppression in Humans

Abstract

IT has been known for over two decades that induction of malignant skin tumors in rodents by midrange UV radiation (UVB radiation, 280 to 320 nm) involves not only an oncogenic event within the epidermis but also specific immunologic changes that serve to prevent or inhibit a vigorous immune response against the incipient tumor by the host immune system. 1 Ultraviolet B—induced tumors in mice are highly immunogenic and fail to grow when transplanted to syngeneic recipients. 2-4 Indeed, the transplanted tumors are destroyed and immunologic memory against the transplanted tumor can be detected. This observation led to a series of studies aimed at understanding why these immunogenic tumors grow in the primary host. UV RADIATION INDUCES SPECIFIC IMMUNOLOGIC CHANGES IN MICE Experiments performed in the 1970s by Kripke 2,3 and Roberts et al 4 demonstrated that prolonged and repetitive exposure to UVB radiation results not only in the appearance