Activated CD4⁺ memory T cells express IL-17 RB. (A) Expression of IL-17RB by CD3⁺ T cells on resting cells and after a 48-hour stimulation with anti-CD3/anti-CD28, with or without IL-25, in an active CSS patient, an atopic patient, and a healthy donor. After gating on IL-17RB⁺ CD3⁺ cells, analysis of CD4 and CD45RA expression revealed that IL-17RB⁺ cells were mainly CD4⁺ CD45RA⁻ memory T cells in an active CSS patient, an atopic patient, and a healthy donor. (B-C) Expression of IL-17RB by CD3⁺ T cells in all tested patients in proportion (B) and in absolute number (C). (D) After gating on IL-17RB⁺ CD3⁺ T cells, analysis of CD4 and CD45RA expression showed that IL-17RB⁺ cells were mainly CD4⁺ CD45RA⁻ memory T cells in CSS patients, atopic patients, and healthy donors. * P < .05; ** P < .01; *** P < .001. Histograms in each panel are representative of 4 to 8 patients in at least 3 independent experiments.