Figure 2: MSCs do not influence U937 leukocyte adhesion molecule expression. A. Schematic of adhesion molecule assay: U937 leukocytes (500,000cells/well) in 6 well plates were cultured with or without MSCs (ratio of 1:5) for 24 hours. The cells were stimulated with PMA (200ng/mL) for 20 minutes. The cells were then labeled with fluorophore conjugated antibodies to CD62L, CD29, CD11b, and CD18. B. Image U937: Representative image of U937 leukocytes alone in culture. C. Image U937 and MSC co-culture: Representative image of U937 leukocytes in co-culture with MSCs. D. Mean Flourescent Intensity changes in all markers (n=4): There were no differences in adhesion molecule expression in U937 leukocytes after co-culture with MSCs and stimulation with PMA. Adhesion molecule expression was quantified by mean fluorescence intensity for four individual culture wells.