Figure 3.

CD47 expression regulates cytotoxic T cell activation, proliferation and antitumor function. (A, B) Pmel-1 CD8+ T cells were stained with CFSE stain to determine if CD47 expression and TSP1 exposure impacted their activation and proliferation through flow cytometry. The BD LSRFortessa X-20 Analyzer was used to acquire data, while FCS Express was used for analysis (*p<0.05, n=3). To determine if CD47 expression and TSP1 exposure impact CD8+ T cell antitumor function, effector (E) Pmel-1 CD8+ T cells were cocultured with target (T) B16 melanoma cells after stimulation with IL-2 and gp100 peptide. Target cell viability was dynamically monitored by surface impedance and presented as (C, D) normalized cell index and (E, F) percent of cytolysis at 18 hours after adding effector Pmel-1 CD8+ T cells (*p<0.05, n=3). CFSE, carboxyfluorescein succinimidyl ester; TSP1, thrombospondin-1.