Fevipiprant, a selective prostaglandin D2 receptor 2 antagonist, inhibits human group 2 innate lymphoid cell aggregation and function  Clare Hardman, PhD, Wentao Chen, MSc, Jian Luo, MD, Paul Batty, MSc, Yi-Ling Chen, DPhil, Janina Nahler, BSc, Yanqiu Wu, MM, Ian D. Pavord, F Med Sci, Veit J. Erpenbeck, MD, David A. Sandham, PhD, Luzheng Xue, PhD, Graham Ogg, BMBCh DPhil  Journal of Allergy and Clinical Immunology  Volume 143, Issue 6, Pages 2329-2333 (June 2019) DOI: 10.1016/j.jaci.2019.02.015 Copyright © 2019 American Academy of Allergy, Asthma & Immunology Terms and Conditions

Fig 1 Effect of fevipiprant on ILC2 migration, survival, and cytokine production. A-C, ILC2 migration to PGD2 (200 nmol/L) in the presence of 1 μmol/L fevipiprant (Fig 1, A) or concentration range of fevipiprant (Fig 1, B) determined with IncuCyte and ILC2 survival measured by using flow cytometry (Fig 1, C). D-G, ILC2s were incubated with combinations of PGD2 (200 nmol/L) and fevipiprant (0.01 nmol/L to 1 μmol/L), and measurements were taken of type 2 cytokine gene expression (Fig 1, D) and protein production (Fig 1, E) and GM-CSF, colony-stimulating factor 1 (CSF-1), and IL-8 gene expression (Fig 1, F) and protein production (Fig 1, G). H, Asthmatic donor (mild-to-moderate asthma, n = 3; severe asthma, n = 3 donors) ILC2s were incubated with combinations of PGD2 (200 nmol/L) and fevipiprant (0.01 nmol/L to 1 μmol/L), and cytokine production was measured. Data are representative of at least 3 independent experiments per donor (n = 3-6 donors). Values are presented as means ± SEMs. Journal of Allergy and Clinical Immunology 2019 143, 2329-2333DOI: (10.1016/j.jaci.2019.02.015) Copyright © 2019 American Academy of Allergy, Asthma & Immunology Terms and Conditions

Fig 2 Effect of fevipiprant on ILC2 aggregation and cytokine production. A-C, ILC2 aggregation induced by PGD2 (200 nmol/L) in the presence of fevipiprant (0.01 nmol/L to 1 μmol/L) measured by means of microscopy in healthy donors (Fig 2, A and B) and asthmatic donors (Fig 2, C). D and E, Adhesion molecule gene expression: ICAM1 (Fig 2, D) and PECAM1 (Fig 2, E) were measured by using quantitative PCR. F, ICAM-1 and PECAM-1 blockade effect on PGD2-induced ILC2 aggregation. G, Effect of fevipiprant (1 μmol/L) and anti–ICAM-1 (20 μg/mL) and anti–PECAM-1 (40 μg/mL) on ILC2 cytokine production after PGD2 stimulation. Data are representative of at least 3 independent experiments (n = 3-6 donors). Values are presented as means ± SEMs. Journal of Allergy and Clinical Immunology 2019 143, 2329-2333DOI: (10.1016/j.jaci.2019.02.015) Copyright © 2019 American Academy of Allergy, Asthma & Immunology Terms and Conditions