Comparison of in-vitro immunomodulatory capacity between large and small apoptotic bodies from human bone marrow mesenchymal stromal cells

Wang, Jiemin, Moosavizadeh, Seyedmohammad, Jammes, Manon, Tabasi, Abbas, Bach, Trung, Ryan, Aideen E., & Ritter, Thomas. (2025). Comparison of in-vitro immunomodulatory capacity between large and small apoptotic bodies from human bone marrow mesenchymal stromal cells. International Immunopharmacology, 153, 114480. doi:https://doi.org/10.1016/j.intimp.2025.114480

Abstract

Background Mesenchymal stromal cell (MSC) apoptosis is essential for their therapeutic effects, including immunomodulation. Previous studies have shown that MSC-derived apoptotic bodies (ApoBDs) also possess immunomodulatory properties. However, compared to small extracellular vesicles, the preparation, characterization, and biological properties of ApoBDs remain underexplored. Results ApoBDs were isolated from the conditioned medium of staurosporine-induced apoptotic human MSCs and categorized into large (∼700 nm) and small (∼500 nm) groups. Both types expressed CD90, CD44, and CD73, with low levels of PD-L1, CD11b, and HLA-DR, mirroring their parental MSCs. Functional assays revealed that both ApoBDs inhibited allogeneic T-cell proliferation, with large ApoBDs demonstrating superior efficacy. In macrophage co-culture experiments, both ApoBDs polarized M1 macrophages toward an M2-like phenotype, with large ApoBDs more effectively upregulating CD163 expression. Additionally, both ApoBDs suppressed the proliferation of murine primary T cells. Furthermore, large ApoBDs exhibited enhanced macrophage uptake, as confirmed by flow cytometry and immunocytochemistry. Importantly, no cytotoxicity was observed for either ApoBD type following staurosporine treatment. Conclusions Staurosporine-induced ApoBDs are non-cytotoxic and exhibit significant immunomodulatory potential in vitro. Large ApoBDs are more effective than small ApoBDs in T-cell suppression and M2 macrophage polarization, suggesting their potential as an alternative to MSC-based therapies in future studies.

Funder

China Scholarship Council
European Union
Taighde Éireann – Research Ireland
European Regional Development Fund (ERDF)

Publisher

Elsevier

Rights

Attribution 4.0 International

cb

Collections

Medicine (Scholarly Articles)