Fig. 3: Als proteins of C. albicans are fungal TIGIT ligands.

a TIGIT activation was assayed using the murine thymoma cell line BW expressing a chimeric TIGIT-ζ-chain receptor. The BW cells were co-incubated for 48 h in the presence or absence of the WT C. albicans strain SC5314 or mutant strains deleted for members of the Als protein family. TIGIT activation was measured using ELISA for IL-2 secreted by the activated BW cells. n = 2–4 independent experiments. Values are shown relative to the TIGIT activation abilities of the WT strain. b Cytotoxicity assay of C. albicans strain SC5314 or mutant strains deleted for members of the Als protein family using primary NK cells isolated from different human donors. The NK cells were blocked or not using an anti-TIGIT antibody. Each line represents a different human donor. c Flow cytometry staining of BW and BW TIGIT cells using NT-Als6-Ig (red empty histogram), NT-Als7-Ig (green empty histogram), NT-Als9-2-Ig (blue empty histogram) or a negative control protein (filled gray histogram). One representative experiment out of 2–4 is presented. d Quantification of the results presented in (c). n = 2–4 independent experiments. Data are presented as mean values ± SEM. e Quantification of flow cytometry staining of BW TIGIT cells using either NT-Als6-Ig, NT-Als7-Ig, NT-Als9-2-Ig in the presence of an anti-TIGIT antibody (red dots) or an isotype control antibody (black dots). Each line represents an independent experiment. Error bars represent the standard error of the mean. Significance was tested using Student’s t test (two-tailed unpaired for (a, d), two-tailed and paired for (b), and one-tailed and paired for (e)). ns = not-significant, * = p < 0.05, ** = p < 0.01, *** = p < 0.005.