[Title] IL-17A–producing sinonasal MAIT cells in patients with chronic rhinosinusitis with nasal polyps

[Author] Min-Seok Rha MD, PhD ^a b, Young Hoon Yoon MD, PhD ^c, June-Young Koh MD ^a, Jae Hyung Jung BSc ^a, Ha Seok Lee MD ^a, Soo Kyoung Park MD, PhD ^c, Su-Hyung Park PhD ^a, Yong Min Kim MD, PhD ^c d, Ki-Sang Rha MD, PhD ^c, Eui-Cheol Shin MD, PhD ^a

^a Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea

^b Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea

^c Department of Otorhinolaryngology–Head and Neck Surgery, Research Institute for Medical Science, Chungnam National University School of Medicine, Daejeon, Korea

^d Department of Medical Science, Chungnam National University School of Medicine, Daejeon, Korea

[Journal] Journal of Allergy and Clinical Immunology Volume 149, Issue 2, February 2022, Pages 599-609.e7

[Abstract]

Background

Diverse immune cells contribute to the pathogenesis of chronic rhinosinusitis (CRS), an inflammatory disease of the nasal cavity and paranasal sinuses. However, whether mucosal-associated invariant T (MAIT) cells are present in human sinonasal tissues remains unclear. Furthermore, the characteristics of sinonasal MAIT cells have not been studied in patients with CRS.

Objective

We investigated the phenotype, function, and clinical implications of MAIT cells in patients with CRS.

Methods

Peripheral blood and sinonasal tissue were obtained from patients with CRS with (CRSwNP) or without nasal polyps (CRSsNP) and healthy controls. MAIT cells were analyzed by flow cytometry.

Results

We found that MAIT cells are present in human sinonasal tissues from healthy controls and patients with CRS. The sinonasal MAIT cell population, but not peripheral blood MAIT cells, from patients with CRSsNP, noneosinophilic CRSwNP (NE-NP), or eosinophilic CRSwNP (E-NP) had a significantly higher frequency of activated cells marked by CD38 expression. In functional analysis, the sinonasal MAIT cell population from NE-NP and E-NP had a significantly higher frequency of IL-17A⁺ cells but lower frequency of IFN-γ⁺ or TNF⁺ cells than control sinonasal tissues. Furthermore, CD38 expression and IL-17A production by sinonasal MAIT cells significantly correlated with disease extent evaluated by the Lund-Mackay computed tomography score in patients with E-NP.

Conclusions

Sinonasal MAIT cells exhibit an activated phenotype and produce higher levels of IL-17A in patients with CRSwNP. These alterations are associated with the extent of disease in patients with E-NP.