Figure 5.

CD47/TSP-1 signaling prevents CD4+ T cell activation in an antigen presentation assay. (A) CD25 expression from CD4+ T cells after antigen presentation, monocyte-derived DCs from psoriasis patients (n = 8) and healthy controls (n = 3) were cultured for 3 days with autologous peripheral blood CD4+ T cells in the presence of staphylococcal enterotoxin E. Where indicated, anti-CD47 (1 μg/ml), IgG1 isotype control (1 μg/ml), or TSP-1 (5 μg/ml) were added. Then, expression of CD25 was evaluated using flow cytometry. Data correspond to mean ± SD and differences were tested using Friedman test, ^**p < 0.01. (B) Knockdown of TSP-1 of moDCs augments the activation of T cells following Ag presentation. Histogram showing the knockdown efficiency of TSP-1 siRNA. Briefly, immature moDCs were transfected by nucleofection with TSP-1 specific or control siRNA (50 pmol), after 48 h moDCs were stimulated with LPS (10 ng/ml) during 12 h and then co-cultured with heterologous CD4+ T cells. Data correspond to one out of three experiments performed by triplicate. Differences were analyzed using Mann-Whitney test, ^*p < 0.05.