(A) IL-2 production was measured by ELISA in resting and 72-hours stimulated naïve CD4+ T cells in response to OVA323-339 peptide presented by control pericytes (PC) and GBC-PC. Results are mean + Standard Deviation from five to six different experiments, ***p<0.005. (B) T cell proliferation was measured by BrdU incorporation in response to antigen presentation by PC and GBC-PC. Results are mean + Standard Deviation from four different experiments, ***p<0.005. (C-D) Cell proliferation and IL-2 production were measured in resting and 72-hours stimulated naïve CD4+ T cells in response to antigen presentation by antigen presenting cells (APC) in presence or not of GBC-PC (APC:GBC-PC; APC). T cells ractivaton in response to antigen presentation was also measured in the presence of control Pericytes (APC:PC) and GBM cells (APC:GB). Results are mean + Standard Deviation from four different experiments. **p<0.01. (E-F) Cell proliferation and IL-2 production were measured in naïve CD4+ T cells stimulated for 72 hours with plate-bound anti-CD3 (αCD3) and anti-CD28 (αCD28) antibodies, in the presence or absence of media from GBC-PC diluted 1:2 in fresh pericyte media (vehicle). Control media from pericytes (PC) and GBM (GB) cell cultures was also diluted in fresh pericyte media and cytokine production and cell proliferation measured in these control conditions. Results are mean + Standard Deviation from three different experiments. **p<0.01. *p<0.05.