Comparison of cellular functionality of human mesenchymal stromal cells and PBMC

BackgroundHuman mesenchymal stromal cells (MSC) and PBMC play significant roles in repair processes following inflammation. Mechanisms of recruitment are still under investigation.Methods and resultsMIP-1α induced the chemotactic migration of MSC but not of PBMC. Correlating with this, 7.7% of MSC expressed the chemokine receptor CCR-1, as shown by FACS analysis. In contrast, PBMC did not express CCR-1 or CCR-2 but did express CXCR-4 (81.9%) and CCR-7 (42.2%). Serum induced the chemotaxis of both cell types, and zymosan activation increased the migration of PBMC but not of MSC. Corresponding with this, C5a induced the migration of PBMC but not of MSC. Dose-dependent and -specific adhesion to fibronectin, fibrinogen, collagen type I and collagen type II could be demonstrated for MSC; in contrast, PBMC did not adhere to any of the investigated proteins. Real-time PCR of receptor expression revealed a 12.2-fold higher expression of αv in MSC compared with PBMC, and a 4.7-fold higher expression of C5a-receptor in PBMC. Incubation of MSC with tumor necrosis factor-α (TNFα) induced NFκB activation and increased the chemotactic response to serum and adhesion to fibronectin.DiscussionChemotaxis and adhesion are crucial and differing cell functions of MSC and PBMC.