TY - JOUR AU - Haderk, Franziska AU - Schulz, Ralph AU - Iskar, Murat AU - Cid, Laura Llaó AU - Worst, Thomas AU - Willmund, Karolin V AU - Schulz, Angela AU - Warnken, Uwe AU - Seiler, Jana AU - Benner, Axel AU - Nessling, Michelle AU - Zenz, Thorsten AU - Göbel, Maria AU - Dürig, Jan AU - Diederichs, Sven AU - Paggetti, Jérôme AU - Moussay, Etienne AU - Stilgenbauer, Stephan AU - Zapatka, Marc AU - Lichter, Peter AU - Seiffert, Martina TI - Tumor-derived exosomes modulate PD-L1 expression in monocytes. JO - Science immunology VL - 2 IS - 13 SN - 2470-9468 CY - Washington, DC PB - AAAS M1 - DKFZ-2017-01480 SP - eaah5509 - PY - 2017 N1 - Science Immunology (Sci. Immunol.) = 2470-9468 (import from CrossRef, PubMed, ) AB - In chronic lymphocytic leukemia (CLL), monocytes and macrophages are skewed toward protumorigenic phenotypes, including the release of tumor-supportive cytokines and the expression of immunosuppressive molecules such as programmed cell death 1 ligand 1 (PD-L1). To understand the mechanism driving protumorigenic skewing in CLL, we evaluated the role of tumor cell-derived exosomes in the cross-talk with monocytes. We carried out RNA sequencing and proteome analyses of CLL-derived exosomes and identified noncoding Y RNA hY4 as a highly abundant RNA species that is enriched in exosomes from plasma of CLL patients compared with healthy donor samples. Transfer of CLL-derived exosomes or hY4 alone to monocytes resulted in key CLL-associated phenotypes, including the release of cytokines, such as C-C motif chemokine ligand 2 (CCL2), CCL4, and interleukin-6, and the expression of PD-L1. These responses were abolished in Toll-like receptor 7 (TLR7)-deficient monocytes, suggesting exosomal hY4 as a driver of TLR7 signaling. Pharmacologic inhibition of endosomal TLR signaling resulted in a substantially reduced activation of monocytes in vitro and attenuated CLL development in vivo. Our results indicate that exosome-mediated transfer of noncoding RNAs to monocytes contributes to cancer-related inflammation and concurrent immune escape via PD-L1 expression. LB - PUB:(DE-HGF)16 C6 - pmid:28754746 DO - DOI:10.1126/sciimmunol.aah5509 UR - https://inrepo02.dkfz.de/record/125347 ER -