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Updated: Jun 18, 2026
Induction of Ocular Surface Inflammation and Collection of Involved Tissues
Published on: August 4, 2022
Topical application of low-concentration IL-2 enhances Treg's function and plays anti-inflammatory roles in
Yilin Liu1, Zhengze Sun2, Qianqian Lan3
1Department of Ophthalmology, Peking University Third Hospital, Beijing, China; Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China; Department of Ophthalmology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China.
Purpose:
To investigate the therapeutic effect of topical low-concentration IL-2 in dry eye disease (DED) and elucidate its underlying mechanisms.
Methods:
During DED induction, mice received topical low-concentration IL-2 (0.1 ng/mL) or PBS. Corneal fluorescein staining (CFS) and tear secretion were evaluated. Tear cytokines were measured using a cytometric bead array, and the cornea underwent RNA-Seq. Immune cells in cervical lymph nodes (CLN), conjunctiva and lacrimal glands were analyzed by flow cytometry. The suppressive function of regulatory T cells (Treg) was assessed by an in vitro Treg suppression assay. CD25+ T cell-depleted mice were generated by intraperitoneal injection of CD25 mAb to determine whether the effect of low-concentration IL-2 was Treg-dependent.
Results:
Topical low-concentration IL-2 significantly improved CFS scores and tear secretion, and decreased tear IL-6 levels. Corneal RNA-Seq revealed IL-17A pathway down-regulation. Low-concentration IL-2 treatment restored the Th17/Treg balance and reduced γδT17 infiltration in CLN, conjunctiva and lacrimal glands. Treg from low-concentration IL-2-treated mice exhibited enhanced suppressive capacity. RNA-Seq of the Treg suppression assay indicated down-regulation of Th17 signaling pathway and up-regulation of Treg signaling pathway. In CD25+ T cell-depleted mice, differences in CFS scores and CLN Th17 proportion between low-concentration IL-2 and PBS groups were abolished; however, corneal Mmp9 expression and the proportions of Th17 and γδT17 in the conjunctiva remained reduced.
Conclusions:
In DED, topical application of low-concentration IL-2 exerts anti-inflammatory effects by enhancing the immunosuppressive function of Treg, which provides a potential therapeutic approach for DED. Treg-independent mechanisms may also contribute to its anti-inflammatory roles.
