Natural killer(NK)cells,as key immune cells,play essential roles in tumor cell immune escape and immunotherapy.Accumulating evidence has demonstrated that the gut microbiota community affects the efficacy of anti-PD1 ...Natural killer(NK)cells,as key immune cells,play essential roles in tumor cell immune escape and immunotherapy.Accumulating evidence has demonstrated that the gut microbiota community affects the efficacy of anti-PD1 immunotherapy and that remodeling the gut microbiota is a promising strategy to enhance anti-PD1 immunotherapy responsiveness in advanced melanoma patients;however,the details of the mechanism remain elusive.In this study,we found that Eubacterium rectale was significantly enriched in melanoma patients who responded to anti-PD1 immunotherapy and that a high E.rectale abundance was related to longer survival in melanoma patients.Furthermore,administration of E.rectale remarkably improved the efficacy of anti-PD1 therapy and increased the overall survival of tumor-bearing mice;moreover,application of E.rectale led to a significant accumulation of NK cells in the tumor microenvironment.Interestingly,conditioned medium isolated from an E.rectale culture system dramatically enhanced NK cell function.Gas chromatography-mass spectrometry/ultrahigh performance liquid chromatography-tandem mass spectrometry-based metabolomic analysis showed that l-serine production was significantly decreased in the E.rectale group;moreover,administration of an l-serine synthesis inhibitor dramatically increased NK cell activation,which enhanced anti-PD1 immunotherapy effects.Mechanistically,supplementation with l-serine or application of an l-serine synthesis inhibitor affected NK cell activation through Fos/Fosl.In summary,our findings reveal the role of bacteria-modulated serine metabolic signaling in NK cell activation and provide a novel therapeutic strategy to improve the efficacy of anti-PD1 immunotherapy in melanoma.展开更多
基金This work was supported by the National Key Research and Development Program of China(No.2021YFA1301200)the National Natural Science(grant No.82073458,82203024,8213000715,81830096,82073018,and 2022YFC2504700)+1 种基金the Science and Technology Innovation Program of Hunan Province(2021RC4013)the Program of Introducing Talents of Discipline to Universities(111 Project,no.B20017).
文摘Natural killer(NK)cells,as key immune cells,play essential roles in tumor cell immune escape and immunotherapy.Accumulating evidence has demonstrated that the gut microbiota community affects the efficacy of anti-PD1 immunotherapy and that remodeling the gut microbiota is a promising strategy to enhance anti-PD1 immunotherapy responsiveness in advanced melanoma patients;however,the details of the mechanism remain elusive.In this study,we found that Eubacterium rectale was significantly enriched in melanoma patients who responded to anti-PD1 immunotherapy and that a high E.rectale abundance was related to longer survival in melanoma patients.Furthermore,administration of E.rectale remarkably improved the efficacy of anti-PD1 therapy and increased the overall survival of tumor-bearing mice;moreover,application of E.rectale led to a significant accumulation of NK cells in the tumor microenvironment.Interestingly,conditioned medium isolated from an E.rectale culture system dramatically enhanced NK cell function.Gas chromatography-mass spectrometry/ultrahigh performance liquid chromatography-tandem mass spectrometry-based metabolomic analysis showed that l-serine production was significantly decreased in the E.rectale group;moreover,administration of an l-serine synthesis inhibitor dramatically increased NK cell activation,which enhanced anti-PD1 immunotherapy effects.Mechanistically,supplementation with l-serine or application of an l-serine synthesis inhibitor affected NK cell activation through Fos/Fosl.In summary,our findings reveal the role of bacteria-modulated serine metabolic signaling in NK cell activation and provide a novel therapeutic strategy to improve the efficacy of anti-PD1 immunotherapy in melanoma.
