Interferon. induced compositional changes in human bone marrow derived mesenchymal stem/stromal cells

Background: Mesenchymal stem/stromal cells ( MSC) display a range of immunoregulatory properties which can be enhanced by the exposure to cytokines such interferon. ( IFN-gamma).However the compositional changes associated with the 'licensing' of these cells have not been clearly defined. The present study was undertaken to provide a detailed comparative proteomic analysis of the compositional changes that occur in human bone marrow derived MSC following 20 h treatment with IFN-gamma. Methods: 2D LC MSMS analysis of control and IFN-gamma treated cells from 5 different healthy donors provided confident identification of more than 8400 proteins. Results: In total 210 proteins were shown to be significantly altered in their expression levels (>=|2SD|) following IFN-gamma treatment. The changes for several of these proteins were confirmed by flow cytometry. STRING analysis determined that approximately 30% of the altered proteins physically interacted in described interferon mediated processes. Comparison of the list of proteins that were identified as changed in the proteomic analysis with data for the same proteins in the Interferome DB indicated that similar to 35% of these proteins have not been reported to be IFN-gamma responsive in a range of cell types. Conclusions: This data provides an in depth analysis of the proteome of basal and IFN-gamma treated human mesenchymal stem cells and it identifies a number of novel proteins that may contribute to the immunoregulatory capacity if IFN-gamma licensed cells.