Linking the microbiome and immune-checkpoint in melanoma by RNF5

项目摘要 该应用程序旨在定义肠道微生物区系控制的新机制--免疫检查点 泛素连接酶RNF5的相互作用及其对黑色素瘤发生的影响 对治疗的反应。尽管在临床治疗方面取得了最令人兴奋和重大的进展 黑色素瘤通过基于免疫检查点的临床试验，潜在的控制机制， 对不同疗法(或不同疗法)的敏感性，是仍未解决的基本问题之一。这里, 我们提供数据支持免疫检查点由肠道微生物群调节的模型，该模型是 由泛素连接酶RNF5定义。我们发现BRAF/Pten突变型黑色素瘤生长受阻 与Rnfwt同基因小鼠相比，同基因Rnf5-/-小鼠与肿瘤的侵袭增强有关- 肿瘤中的浸润性淋巴细胞(TIL)(CD4和CD8阳性)、巨噬细胞和树突状细胞 在RNF5-/-小鼠中发育明显减慢。引人注目的是，Rnf5-/-和Rnfwt动物或 抗生素消融肠道微生物区系导致上述表型的丧失--肿瘤生长不再 减毒和基于免疫检查点的表型大部分丢失。肠道微生物群的评估 揭示了一组不同的细菌种类，将RNF5-/-小鼠与它们的WT窝种区分开来(全部 “纯”内部保持的C57BL/6毒株)。值得注意的是，不同的RNF5微生物群的共同之处是细菌 产生选定的短链脂肪酸子集的物种。这些观察结果为 我们关于RNF5控制影响免疫检查点的肠道微生物区系的假设 机制，进而影响黑色素瘤的发展。我们拟议的研究将(I)定义RNF5 对肠道微生物组-肿瘤相互作用的影响，(Ii)确定微生物组调控中的依赖变化 RNF5对肿瘤免疫检查点的调控，以及(Iii)确定RNF5的生理意义和影响 RNF5对不同品系、年龄和年龄的小鼠黑色素瘤发生的微生物群和免疫检查点的控制 在精选联合疗法下。我们高度集成的研究将定义基本机制， 为肠道微生物群和免疫检查点的调节奠定了基础，从而为 黑色素瘤和其他癌症的治疗方式。

Project Summary This application is set to define a novel mechanism underlying the control of gut microbiota-immune checkpoint interactions by the ubiquitin ligase RNF5, and the implications of such regulation to melanoma development and response to therapy. Despite the most exciting and significant advances made in clinical management of melanoma via the immune-checkpoint based clinical trials, mechanisms underlying their control, the susceptibility to distinct therapies (or not), are among the fundamental questions that remain unsolved. Here, we provide data to support a model whereby immune checkpoints are regulated by gut microbiome, which is defined by the ubiquitin ligase RNF5. Our discovery of impaired growth of Braf/Pten mutant melanoma in syngeneic Rnf5–/– mice, compared with Rnfwt littermates, was linked with enhanced infiltration of tumor- infiltrating lymphocytes (TILs) (CD4 and CD8 positive), macrophages and dendritic cells in the tumors that developed significantly slower in the Rnf5–/– mice. Strikingly, co-housing the Rnf5–/– and Rnfwt animals or antibiotic ablation of the gut microbiota resulted in loss of the above phenotypes—tumor growth was no longer attenuated and immune checkpoint-based phenotypes were largely lost. Assessment of the gut microbiome revealed a distinct subset of bacterial species, which distinguish Rnf5–/– mice from their WT littermates (all “pure” in-house maintained C57BL/6 strain). Notably, common to the distinct RNF5-microbiome are bacterial species that generate select subset of short chain fatty acids. These observations provide the foundation for our hypothesis that RNF5 controls the intestinal microbiota that affects immune checkpoint mechanisms, which in turn impacts melanoma development. Our proposed studies will (i) define RNF5 effect on the gut microbiome–tumor interactions, (ii) identify microbiome-dependent changes in the regulation of tumor immune checkpoint control by RNF5, and (iii) establish the physiological significance and impact of RNF5 control of microbiome and immune checkpoint on melanomagenesis in different mouse strains, age, and under select combination therapies. Our highly integrated studies will define the fundamental mechanisms that underlie the regulation of both gut microbiome and immune checkpoints, thereby providing new insights into therapeutic modalities for melanoma and other cancers.