Abstract
Purpose :
While the eye is an immune privileged site, many of its tissues harbor resident immune cells that are considered the sentinels of the immune system whose primary function is as immediate responders to wounding. We have identified that resident immune cells are a feature of the lens across species. In this study we examine the pathway(s) by which resident immune cells populate the lens during development, their response to external injury signals, and their role in the recruitment of monocytes/macrophages to the avascular lens.
Methods :
Chick eye cryosections from different stages of development were co-immunolabeled for immune cell antigens and matrix proteins of the ciliary zonules and vitreous. The response of lens resident immune cells of E15 lenses to the cytokine interferon gamma (INF-γ) was examined in studies performed in organ culture. The migration of RAW cells, a monocyte/macrophage cell line, to activated lens resident immune cells, was studied using Boyden chamber transwell plates. Imaging for all studies was performed by confocal microscopy.
Results :
The ciliary zonules linking the avascular lens with the highly vascularized ciliary body was identified as a primary migratory pathway of tissue resident immune cells to the developing lens. Exposure of lenses in organ culture to INF-γ induced activation of the lens resident immune cells, their rapid response to this cytokine demonstrated by their altered morphology. The functional role of lens resident immune cells in response to this inflammation-associated cytokine was demonstrated by the ability of the INF-γ-activated lens resident immune cells to induce RAW cells migration through transwell filters.
Conclusions :
The activation of the lens resident immune cells that populate the lens during development induces the recruitment of macrophages to the lens.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.