Fig. 4

Lymphocyte response to ATP exposure. a PMBCs were cultured with or without MSCs during the first 8 h of stimulation and then allowed to grow until 96 h after co-stimulation. b The lymphocyte population of PBMCs was gated using flow cytometry and as ATP exposure increases, the proliferation of lymphocytes only decreases. At 1 mM exposure, proliferation is completely restored, and at 2 mM, MSCs allow for significantly more proliferation than the control. HEK cells which do not express the ecto-enzymes for ATP hydrolysis were included as a negative control. c At low levels of ATP exposure, cytotoxicity is lower in MSC co-cultured groups and as ATP dose increases, the 50,000 MSCs are insufficient in hydrolyzing the ATP enough to reduce cytotoxicity compared to the negative control. For both response experiments, n = 3