Monitoring Cellular Movement with Photoconvertible Fluorescent Protein and Single-Cell RNA Sequencing Reveals Cutaneous Group 2 Innate Lymphoid Cell Subtypes, Circulating ILC2 and Skin-Resident ILC2

Minori Nakatani-Kusakabe; Koubun Yasuda; Michio Tomura; Makoto Nagai; Kiyofumi Yamanishi; Etsushi Kuroda; Nobuo Kanazawa; Yasutomo Imai

doi:10.1016/j.xjidi.2021.100035

Monitoring Cellular Movement with Photoconvertible Fluorescent Protein and Single-Cell RNA Sequencing Reveals Cutaneous Group 2 Innate Lymphoid Cell Subtypes, Circulating ILC2 and Skin-Resident ILC2

JID Innov. 2021 Jul 2;1(3):100035. doi: 10.1016/j.xjidi.2021.100035. eCollection 2021 Sep.

Authors

Minori Nakatani-Kusakabe¹, Koubun Yasuda², Michio Tomura³, Makoto Nagai¹, Kiyofumi Yamanishi¹, Etsushi Kuroda², Nobuo Kanazawa¹, Yasutomo Imai¹

Affiliations

¹ Department of Dermatology, Hyogo College of Medicine, Nishinomiya, Japan.
² Department of Immunology, Hyogo College of Medicine, Nishinomiya, Japan.
³ Laboratory of Immunology, Faculty of Pharmacy, Osaka Ohtani University, Osaka, Japan.

Abstract

We previously generated a transgenic mouse line expressing skin-specific IL-33 (IL33tg mice) and showed that IL-33 elicits group 2 innate lymphoid cell (ILC2)-dependent atopic dermatitis-like skin inflammation. ILC2s are believed to be tissue-resident cells under steady-state conditions, but the dynamics of ILC2 migration are not fully understood. We sorted ILC2s from the skin and draining lymph nodes of IL33tg mice and analyzed their transcriptomes using the single-cell RNA sequencing technique, which revealed that the skin ILC2s had split into two clusters: circulating ILC2 and skin-resident ILC2. The circulating ILC2s expressed H2-related major histocompatibility complex class II genes. Conversely, the skin-resident ILC2s demonstrated increased mRNA expression of the ICOS, IL-5, and IL-13. Next, we tracked ILC2 migration using IL33tg-Kikume Green-Red mice. Exposing the IL33tg-Kikume Green-Red mice's inflamed skin to violet light allowed us to label the circulating ILC2s in their skin and track the ILC2 migration from the skin to the draining lymph nodes. Cutaneous local innate responses could transition to systemic type 2 responses by migrating the activated ILC2s from the skin into the draining lymph node. Conversely, the skin-resident ILC2s produced a large number of cytokines. Thus, the skin ILC2s turned out to be a heterogeneous cell population.

Keywords: AD, atopic dermatitis; DC, dendritic cell; ILC2, group 2 innate lymphoid cell; KikGR, Kikume Green-Red; MHC, major histocompatibility complex; RNA-seq, RNA sequencing; dLN, draining lymph node.