Alkali injury–induced pathological lymphangiogenesis in the iris facilitates the infiltration of T cells and ocular inflammation
Zheng Liu, Keli Liu, Shunhua Shi, Xun Chen, Xinyu Gu, Weifa Wang, Keli Mao, Rukeye Yibulayi, Wanwen Wu, Lei Zeng, Weibin Zhou, Xiaofeng Lin, Feng Zhang, Bingsheng Lou
Zheng Liu, Keli Liu, Shunhua Shi, Xun Chen, Xinyu Gu, Weifa Wang, Keli Mao, Rukeye Yibulayi, Wanwen Wu, Lei Zeng, Weibin Zhou, Xiaofeng Lin, Feng Zhang, Bingsheng Lou
View: Text | PDF
Research Article Immunology Ophthalmology

Alkali injury–induced pathological lymphangiogenesis in the iris facilitates the infiltration of T cells and ocular inflammation

Abstract

Inflammatory lymphangiogenesis is intimately linked to immune regulation and tissue homeostasis. However, current evidence has suggested that classic lymphatic vessels are physiologically absent in intraocular structures. Here, we show that neolymphatic vessels were induced in the iris after corneal alkali injury (CAI) in a VEGFR3-dependent manner. Cre-loxP–based lineage tracing revealed that these lymphatic endothelial cells (LECs) originate from existing Prox1+ lymphatic vessels. Notably, the ablation of iridial lymphangiogenesis via conditional deletion of VEGFR3 alleviated the ocular inflammatory response and pathological T cell infiltration. Our findings demonstrate that iridial neolymphatics actively participate in pathological immune responses following injury and suggest intraocular lymphangiogenesis as a valuable therapeutic target for the treatment of ocular inflammation.

Authors

Zheng Liu, Keli Liu, Shunhua Shi, Xun Chen, Xinyu Gu, Weifa Wang, Keli Mao, Rukeye Yibulayi, Wanwen Wu, Lei Zeng, Weibin Zhou, Xiaofeng Lin, Feng Zhang, Bingsheng Lou

×

Figure 2

LECs in CAI-induced neolymphatics have a Prox1+, CDH5+, PDGFRβ–, and CX3CR1– lineage.

Options: View larger image (or click on image) Download as PowerPoint
LECs in CAI-induced neolymphatics have a Prox1+, CDH5+, PDGFRβ–, and CX3...
(A) Schematic showing generation of mice harboring the CAG-tdTomato reporter and CreERT2 transgene and experimental timeline of tamoxifen (TAM) administration and CAI for lineage tracing in the indicated mouse lines in B–G. Arrows indicate TAM administered 5 times (80 mg/kg) i.p. injections in week 4, followed by CAI treatment at week 6 and analysis at week 10. (B and D) Representative tdTomato, Prox1, and Lyve1 immunostaining images of the iris whole mounts from Prox1-CreERT2;CAG-tdTomato (B) or CDH5-CreERT2;CAG-tdTomato (D) mice at week 10 that received TAM administered 5 times i.p. in week 4 and CAI treatment at week 6. Note overlapping of tdTomato-labeled area with Prox1/Lyve1-labeled lymphatic areas in both mouse lines with CAI treatment, indicating that LECs in CAI-induced neolymphatics originate from Prox1+ and CDH5+ existing lymphatics. Scale bars: 100 μm. (C and E) Quantification of the ratio of tdTomato-labeled area and Prox1/Lyve1-labeled area in B and D. Data are shown as mean ± SEM. n = 4 mice per group. Each dot represents 1 mouse. (F) Representative immunostaining images of tdTomato and Prox1 of the iris whole mounts from PDGFRB-CreERT2;CAG-tdTomato or CX3CR1-CreERT2;CAG-tdTomato mice at week 10 that received TAM administered 5 times i.p. in week 4 and CAI or sham treatment at week 6. Note that Prox1 staining does not overlap with tdTomato-labeled area in both mouse lines with CAI treatment, indicating that LECs in CAI-induced neolymphatics do not originate from PDGFRβ+ mural cells or CX3CR1+ myeloid cells. Scale bar: 100 μm. (G) Quantification of number of Prox1 and tdTomato double-positive cells in F. Data are shown as mean ± SEM. n = 4 mice per group. Each dot represents 1 mouse. (H) Immunofluorescence staining for Lyve1 in sagittal cryosections of the anterior segment of the eyes from WT mice at week 10 that received CAI or sham treatment at week 6. The dotted line depicts the injured iris. Scale bar: 200 μm. (I) Diagram showing possible route of the induction of the iridial neolymphatics from existing limbal lymphatic vessels (LVs).