Extracellular vesicles released by CD40/IL-4-stimulated CLL cells confer altered functional properties to CD4+ T cells.
The complex interplay between cancer cells, stromal cells, and immune cells in the tumor microenvironment (TME) regulates tumorigenesis and provides emerging targets for immunotherapies. Crosstalk between CD4(+) T cells and proliferating chronic lymphocytic leukemia (CLL) tumor B cells occurs within lymphoid tissue pseudofollicles, and investigating these interactions is essential to understand both disease pathogenesis and the effects of immunotherapy. Tumor-derived extracellular vesicle (EV) shedding is emerging as an important mode of intercellular communication in the TME. In order to characterize tumor EVs released in response to T-cell-derived TME signals, we performed microRNA (miRNA [miR]) profiling of EVs released from CLL cells stimulated with CD40 and interleukin-4 (IL-4). Our results reveal an enrichment of specific cellular miRNAs including miR-363 within EVs derived from CD40/IL-4-stimulated CLL cells compared with parental cell miRNA content and control EVs from unstimulated CLL cells. We demonstrate that autologous patient CD4(+) T cells internalize CLL-EVs containing miR-363 that targets the immunomodulatory molecule CD69. We further reveal that autologous CD4(+) T cells that are exposed to EVs from CD40/IL-4-stimulated CLL cells exhibit enhanced migration, immunological synapse signaling, and interactions with tumor cells. Knockdown of miR-363 in CLL cells prior to CD40/IL-4 stimulation prevented the ability of CLL-EVs to induce increased synapse signaling and confer altered functional properties to CD4(+) T cells. Taken together, these data reveal a novel role for CLL-EVs in modifying T-cell function that highlights unanticipated complexity of intercellular communication that may have implications for bidirectional CD4(+) T-cell:tumor interactions within the TME.
Department of Cancer Studies, and Ernest and Helen Scott Haematology Research Institute, University of Leicester, Leicester, United Kingdom;
Dawn T
DT
Smallwood
Department of Haemato-Oncology, Division of Cancer Studies, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom;
Benedetta
B
Apollonio
Department of Cancer Studies, and Ernest and Helen Scott Haematology Research Institute, University of Leicester, Leicester, United Kingdom;
Shaun
S
Willimott
Department of Cancer Studies, and Ernest and Helen Scott Haematology Research Institute, University of Leicester, Leicester, United Kingdom;
Larissa
L
Lezina
Department of Cancer Studies, and Ernest and Helen Scott Haematology Research Institute, University of Leicester, Leicester, United Kingdom;
Afaf
A
Alharthi
Department of Cardiovascular Sciences, University of Leicester, Leicester, United Kingdom; and.
Ashley R
AR
Ambrose
Centre for Microvascular Research, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.
Giulia
G
De Rossi
Department of Haemato-Oncology, Division of Cancer Studies, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom;
Alan G
AG
Ramsay
Department of Cancer Studies, and Ernest and Helen Scott Haematology Research Institute, University of Leicester, Leicester, United Kingdom;
Simon D
SD
Wagner
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology; D019013:CD40 Antigens / Q000276:immunology*; D002450:Cell Communication / Q000276:immunology*; D005260:Female; D006801:Humans; D015847:Interleukin-4 / Q000276:immunology*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology* / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000276:immunology; D009363:Neoplasm Proteins / Q000276:immunology*; D012334:RNA, Neoplasm / Q000276:immunology; D022142:Secretory Vesicles / Q000276:immunology* / Q000473:pathology; D014407:Tumor Cells, Cultured
D019013:CD40 Antigens; C508598:IL4 protein, human; C574861:MIRN363 microRNA, human; D035683:MicroRNAs; D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D015847:Interleukin-4