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ORIGINAL RESEARCH article

Front. Immunol.

Sec. Immunological Tolerance and Regulation

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1640168

This article is part of the Research TopicHLA-G in Health and Disease: Comprehensive Insights and Future Therapeutic DirectionsView all articles

Bone Marrow-Derived Extracellular Vesicles from Multiple Myeloma Patients Promote Adaptive Immune Dysfunction via HLA-G, PD-1, and PD-L1

Provisionally accepted
Debora  SonciniDebora Soncini1Danilo  MarimpietriDanilo Marimpietri2Francesco  LadisaFrancesco Ladisa1Francesco  LaiFrancesco Lai1Irma  AiroldiIrma Airoldi2Roberto  GramignoliRoberto Gramignoli2Michele  CeaMichele Cea1,3Fabio  MorandiFabio Morandi2*
  • 1Universita degli Studi di Genova, Genoa, Italy
  • 2IRCCS Istituto Giannina Gaslini, Genova, Italy
  • 3IRCCS Ospedale Policlinico San Martino, Genoa, Italy

The final, formatted version of the article will be published soon.

Extracellular vesicles (EVs) are critical mediators of intercellular communication and contribute to cancer progression and immune regulation. We characterized EVs isolated from bone marrow (BM) plasma harvested from healthy donors and patients affected by Multiple Myeloma (MM). EVs from MM patients were significantly more abundant and enriched in CD138, supporting their partial origin from malignant plasma cells, with additional input from BM resident cells, including monocytes and NK cells. Phenotypic profiling revealed increased expression of immune checkpoint molecules HLA-G, PD-1, and PD-L1 on MM-derived EVs compared to healthy controls. Functionally, MM-EVs suppressed Staphylococcal enterotoxin B (SEB)-induced T cell activation, as evidenced by reduced IFN-γ production and CD4⁺ T cell proliferation. Such effects were partially reversed by HLA-G blockade. Moreover, MM-derived EVs modulated cytokine secretion profiles suppressing IL-2, IFNα, TNF-α, and IL-6, and enhancing GM-CSF, with some changes attributed to HLA-G and PD-L1 activity. Transcriptomic analysis showed higher HLA-G expression in patients with gain of chromosome 1q, suggesting a link between high-risk cytogenetics and EV-driven immune suppression. While clinical correlations were not observed, likely due to limited sample size, these findings underscore the immunosuppressive role of MM-derived EVs. In conclusion, HLA-G⁺, PD-1⁺, and PD-L1⁺ EVs contribute to immune dysfunction in MM and represent promising targets to restore antitumor immunity.

Keywords: Multiple Myeloma, extracellular vesicles, immune checkpoints, HLA-G, PD-L1

Received: 03 Jun 2025; Accepted: 08 Aug 2025.

Copyright: © 2025 Soncini, Marimpietri, Ladisa, Lai, Airoldi, Gramignoli, Cea and Morandi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Fabio Morandi, IRCCS Istituto Giannina Gaslini, Genova, Italy

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