Reprogramming the immunosuppressive milieu in pancreatic cancer(PaCa)remains an important yet unmet therapeutic goal.Although tumor-associated macrophages(TAMs)are known to promote tumor growth and metastasis,little i...Reprogramming the immunosuppressive milieu in pancreatic cancer(PaCa)remains an important yet unmet therapeutic goal.Although tumor-associated macrophages(TAMs)are known to promote tumor growth and metastasis,little is known about the underlying mechanisms driving macrophage plasticity in PaCa.Herein,we show that extracellular vesicles(EVs)released by PaCa cells as well as circulating EVs in patient plasma,facilitate cellular crosstalk thereby promoting preferential skewing of recipient macrophages towards an M2-like TAM phenotype.PaCa-EV educated macrophages predominantly secrete anti-inflammatory cytokines,adapt an M2-like metabolic phenotype,have a higher expression of PD-L1,and suppress the proliferation of CD8+T cells.An increased payload of miR-182-5p in PaCa-EV cargo causes a decrease in TLR4 expression in recipient macrophages and a concomitant upregulation of JAK/STAT3 pathway and elevated secretion of IL-10 and TGF-β,leading to increased PD-L1 expression.Most notably,targeted therapeutic delivery of antagomiR-182-5p in pancreatic tumor-bearing mice with varying immunogenic potential results in a significant decrease in tumor volume,increased survival,restoration of M1/M2 ratio,and an overall increase in CD8+T cell activation in the TME.Taken together,we demonstrate a direct role of EVs in subverting the immune microenvironment and altering macrophage plasticity in a manner conducive to both tumor growth and proliferation.As such,a targeted delivery of microRNA inhibitors as drugs for altering macrophage plasticity may likely achieve better therapeutic response in pancreatic tumors.展开更多
基金Authors would like to sincerely thank Dr.Trevino(School of Medicine Surgery,Virginia Commonwealth University)for sharing patient-derived xenograft PDAC cell lines(PPCL-46 and PPCL-68)We thank Dr.David A Tuveson(Cold Spring Harbor Laboratory)for the murine PaCa cell line mT3-2D+6 种基金We also thank Dr.Chunling Yi(Georgetown University)for sharing GFP/luciferase-expressing mT3-2D cellsMany thanks to Dr.Jeff Huang for providing access to confocal microscopy imagingWe also thank Ms.Jiva and Mr.Phil Gross for assisting us with IMARIS usageWe would also like to thank the Metabolomics Shared Resource,Flow Cytometry&Cell Sorting Shared Resource,Tissue Culture&Biobanking Shared Resource,Microscopy&Imaging Shared Resource(MISR),Histopathology&Tissue Shared Resource,Division of Comparative Medicine(DCM)and Preclinical Imaging Research Laboratory(PIRL)at Georgetown University,all partially supported by NIH/NCI grant P30-CA051008Special thanks to Drs.Karen Creswell(Flow Cytometry&Cell Sorting Shared Resource)and Anju Duttargi(Histopathology&Tissue Shared Resource)for their help during the studySincere thanks to Dr.Kelly Dryden from the University of Virginia for the transmission electron microcopy services at the Molecular Electron Microscopy Core facility,University of Virginia Molecular(RRID:SCR_019031)which is supported in part by the School of Medicine and built with NIH grant G20-RR31199.
文摘Reprogramming the immunosuppressive milieu in pancreatic cancer(PaCa)remains an important yet unmet therapeutic goal.Although tumor-associated macrophages(TAMs)are known to promote tumor growth and metastasis,little is known about the underlying mechanisms driving macrophage plasticity in PaCa.Herein,we show that extracellular vesicles(EVs)released by PaCa cells as well as circulating EVs in patient plasma,facilitate cellular crosstalk thereby promoting preferential skewing of recipient macrophages towards an M2-like TAM phenotype.PaCa-EV educated macrophages predominantly secrete anti-inflammatory cytokines,adapt an M2-like metabolic phenotype,have a higher expression of PD-L1,and suppress the proliferation of CD8+T cells.An increased payload of miR-182-5p in PaCa-EV cargo causes a decrease in TLR4 expression in recipient macrophages and a concomitant upregulation of JAK/STAT3 pathway and elevated secretion of IL-10 and TGF-β,leading to increased PD-L1 expression.Most notably,targeted therapeutic delivery of antagomiR-182-5p in pancreatic tumor-bearing mice with varying immunogenic potential results in a significant decrease in tumor volume,increased survival,restoration of M1/M2 ratio,and an overall increase in CD8+T cell activation in the TME.Taken together,we demonstrate a direct role of EVs in subverting the immune microenvironment and altering macrophage plasticity in a manner conducive to both tumor growth and proliferation.As such,a targeted delivery of microRNA inhibitors as drugs for altering macrophage plasticity may likely achieve better therapeutic response in pancreatic tumors.
