Supplemental Figures 1 through 5 from Neutralization of Tumor Acidity Improves Antitumor Responses to Immunotherapy

Supplemental Figure S1: Inhibition of PI3 kinase signaling leads to loss of T cell function. Activated T cells were cultured at pH 6.6 or 7.4 for 24h in presence or absence of the PI3K Supplemental Figure S2: OT-1 T cell metabolism. OT-1 T cells were cultured with OVASIINFEKL peptide for 48 hours at either pH 6.6 or 7.4. Cells were subsequently metabolically profiled using a Seahorse XF-96 analyzer. Supplemental Figure S3: Knocking out the acid sensor, TDAG8, does not rescue IFN-gamma production by T cells. T cells were isolated from TDAG8 k/o or wild-type (WT) mice and stimulated in the presence of 10 ug/ml plate-bound anti-CD3 antibodies for 48 hours at pH 6.6 or 7.4. Supernatants were collected and IFN-gamma was measured by ELISA. Supplemental Figure S4: Representative B16 tumors in mice treated with anti-CTLA4 antibodies with or without buffer therapy. Supplemental Figure S5: Buffer therapy has little effect on systemic T cell activity in B16- bearing mice treated with anti-PD-1 antibody. inhibitor BEZ-235.