IL-17 Triggers Invasive and Migratory Properties in Human MSCs, while IFNy Favors their Immunosuppressive Capabilities: Implications for the “Licensing” Process

• Published in: Stem cell reviews and reports 2020-12, Vol.16 (6), p.1266-1279
• Main Authors: Du-Rocher, Bárbara, Binato, Renata, de-Freitas-Junior, Julio Cesar Madureira, Corrêa, Stephany, Mencalha, André Luiz, Morgado-Díaz, José Andrés, Abdelhay, Eliana
• Format: Article
• Language: English
• Subjects: Animal models; Antigen presentation; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Cell Biology; Cell therapy; Chemokines; Immunomodulation; Immunosuppression; Inflammation; Interleukin 17; Leukocyte migration; Life Sciences; Lymphocytes; Mesenchymal stem cells; Mesenchyme; Metalloproteinase; Regenerative Medicine/Tissue Engineering; Stem Cells; Stromal cells
• ISSN: 2629-3269; 2629-3277
• DOI: 10.1007/s12015-020-10051-4

Mesenchymal stromal cells (MSCs) were first used as a source for cell therapy in 1995; however, despite their versatility and unambiguous demonstration of efficacy and safety in preclinical/phase I studies, the positive effect of MSCs in human phase III studies did not resemble the success obtained in mouse models of disease. This dissonance highlights the need to more thoroughly study the immunobiology of MSCs to make better use of these cells. Thus, we aimed to study the immunobiology of MSCs by using chip array analysis as a method for general screening to obtain a global picture in our model study and found IFNy and IL-17 signaling as the first two “top canonical pathways” involved in MSCs immunomodulation. The role of IFNy in triggering the immunosuppressive properties of MSCs is well recognized by many groups; however, the role of IL-17 in this process remains uncertain. Interestingly, in contrast to IFNy, which actively improved the MSCs-mediated immunosuppression, IL-17 did not improve directly the MSCs-mediated immunosuppression. Instead, IL-17 signaling induced the migration of MSCs and inflammatory cells, bringing these cell types together and increasing the likelihood of the lymphocytes sensing the immunosuppressive molecules produced by the MSCs. These effects also correlated with high levels of cytokine/chemokine production and metalloprotease activation by MSCs. Importantly, this treatment maintained the MSCs safety profile by not inducing the expression of molecules related to antigen presentation. In this way, our findings highlight the possibility of using IL-17, in combination with IFNy, to prime MSCs for cell therapy to improve their biological properties and thus their therapeutic efficacy. Finally, the use of preactivated MSCs may also minimize variations among MSCs to produce more uniform therapeutic products. In the not-so-distant future, we envisage a portfolio of MSCs activated by different cocktails specifically designed to target and treat specific diseases. Graphical abstract