Fig 2: CD155low-expressing antigen-presenting cells in GCACD14+ cells isolated from the peripheral blood of patients with GCA and age-matched controls were differentiated into monocyte-derived Mfs and stimulated with LPS/IFN-?.(A and B) Flow cytometric analysis of CD155 on Mfs from a patient with GCA (A; n = 12) or GPA as a disease control (B; n = 5). Representative histograms and MFI are shown.(C) Comparison of CD155 expression on Mfs from 7 untreated patients with GCA, 6 corticosteroid-treated patients with GCA, and 7 age-matched controls. Individual MFIs are shown.(D) Dual-color immunofluorescence staining of tissue sections for CD68 (green) and the checkpoint ligand CD155 (red). Nuclei marked with DAPI (blue). Temporal arteries were collected from patients with GCA and sinonasal biopsies from patients with GPA. Frequencies of CD68+ CD155high Mfs were counted in 50 distinct tissue regions. Representative data from 5 tissues. Scale bar: 20 µm.(E) Immunoblotting of total cell CD155 protein in control and GCA Mfs. ß-Actin served as loading control. Bar graph shows protein quantification in individual patients and controls.(F) Monocyte-derived Mfs were induced from patients with GCA and age-matched controls, and CD155 mRNA transcripts were quantified by RT-PCR. Data from 12 patients and 12 controls.Mean ± SEM with individual values shown. (A, B, and E) Two-tailed unpaired t test. (C) One-way ANOVA with Tukey’s multiple-comparisons test. (F) Mann-Whitney test. ***p < 0.001, n.s., not significant.

Fig 3: CD155-CD96 interaction promotes differentiation of IL-9-producing effector T cellsMonocyte-derived Mfs were generated from patients with GCA or healthy controls and used as antigen-presenting cells (APCs) for CD4+ T cells. Induction of T cell effector cytokines was assessed by RT-PCR or flow cytometry.(A) CD4+ T cells from the Mf-T cell co-cultures were isolated after 72 h. Transcripts for 15 pro-inflammatory effector cytokines were quantified by RT-PCR. Each column represents Mfs from one patient or one control.(B–E) Frequencies of IL-9-producing (B and C), IFN-?-producing (D), or TNF-a-producing (E) CD4+ T cells induced by healthy, GCA, or GPA (C) Mfs. Effector cytokines were measured by flow cytometry. Frequencies of cytokine-producing CD4+ T cells from 6 to 12 independent experiments are presented.(F) CD4+ T cells were stimulated with healthy Mfs in the absence and presence of anti-CD155 antibody. Intracellular IL-9 protein expression in T cells was analyzed by flow cytometry. Frequencies of IL-9-producing CD4+ T cells from 8 experiments.(G) CD4+ T cells were stimulated with healthy Mfs in the absence and presence of anti-CD96 antibody. Induction of IL-9-producing T cells was determined by flow cytometry. Frequencies of IL-9-producing CD4+ T cells from 6 experiments.Mean ± SEM with individual values shown. (A and C–G) Two-tailed paired t test. (B) Wilcoxon matched-pairs signed rank test. **p < 0.01, ***p < 0.001, n.s., not significant.