Figure 4: TIGIT on Treg does not affect Treg suppressive function in the context of CTLA-4Ig.

Differential gene expression was calculated for genes related to Treg function (A). Treg suppressor function was measured by Treg suppression assays where Treg were isolated from spleens of naïve WT (Foxp3-Cre × TIGIT^WT/WT) or TIGIT cKO (Foxp3-Cre × TIGIT^fl/fl) mice by MACS enrichment prior to plating with Cell Trace Violet (CTV) labeled splenocytes from OT-I mouse spleens. Cells were stimulated with SIINFEKL peptide and treated with 100μg/mL CTLA-4Ig, 100 μg/mL TIGIT agonist, or CTLA-4Ig+TIGIT agonist in culture for 3 days. Dilution of CTV was measured and the percent suppression was calculated (representative flow B, summarized for 2 independent experiments in C). Treg were cultured with naïve splenocytes and quantified by flow cytometry after 3 days in culture (summarized D), data are from 2 independent experiments. Non-parametric Mann Whitney T-tests were performed to determine p values in C, D. Non-parametric paired t-test was performed in E.