RESUMEN
Studies suggest that the efficacy of cancer chemotherapy and immunotherapy is influenced by intestinal bacteria. However, the influence of the microbiome on radiation therapy is not as well understood, and the microbiome comprises more than bacteria. Here, we find that intestinal fungi regulate antitumor immune responses following radiation in mouse models of breast cancer and melanoma and that fungi and bacteria have opposite influences on these responses. Antibiotic-mediated depletion or gnotobiotic exclusion of fungi enhances responsiveness to radiation, whereas antibiotic-mediated depletion of bacteria reduces responsiveness and is associated with overgrowth of commensal fungi. Further, elevated intratumoral expression of Dectin-1, a primary innate sensor of fungi, is negatively associated with survival in patients with breast cancer and is required for the effects of commensal fungi in mouse models of radiation therapy.
Asunto(s)
Antifúngicos/administración & dosificación , Bacterias/clasificación , Neoplasias de la Mama/terapia , Hongos/efectos de los fármacos , Lectinas Tipo C/genética , Melanoma/terapia , Animales , Antifúngicos/farmacología , Bacterias/inmunología , Neoplasias de la Mama/inmunología , Neoplasias de la Mama/microbiología , Terapia Combinada , Regulación hacia Abajo , Femenino , Hongos/clasificación , Hongos/inmunología , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/efectos de la radiación , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Humanos , Melanoma/inmunología , Melanoma/microbiología , Ratones , Simbiosis , Linfocitos T/metabolismo , Macrófagos Asociados a Tumores/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/efectos de la radiación , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Radiation continues to play a major role in the treatment of almost every cancer type. Traditional radiation studies focused on its ability to damage DNA, but recent evidence has demonstrated that a key mechanism driving the efficacy of radiation in vivo is the immune response triggered in irradiated tissue. Innate immune cells including macrophages, dendritic cells, and natural killer cells are key mediators of the radiation-induced immune response. They regulate the sensing of radiation-mediated damage and subsequent radiation-induced inflammation. Given the importance of innate immune cells as determinants of the post-radiation anti-tumor immune response, much research has been devoted to identify ways to both enhance the innate immune response and prevent their ability to suppress ongoing immune responses. In this review, we will discuss how the innate immune system shapes anti-tumor immunity following radiation and highlight key strategies directed at the innate immune response to enhance the efficacy of radiation.
