Resident immune cells of the avascular lens: Mediators of the injury and fibrotic response of the lens.

Tissues typically harbor subpopulations of resident immune cells that function as rapid responders to injury and whose activation leads to induction of an adaptive immune response, playing important roles in repair and protection. Since the lens is an avascular tissue, it was presumed that it was absent of resident immune cells. Our studies now show that resident immune cells are a shared feature of the human, mouse, and chicken lens epithelium. These resident immune cells function as immediate responders to injury and rapidly populate the wound edge following mock cataract surgery to function as leader cells. Many of these resident immune cells also express MHCII providing them with antigen presenting ability to engage an adaptive immune response. We provide evidence that during development immune cells migrate on the ciliary zonules and localize among the equatorial epithelial cells of the lens adjacent to where the ciliary zonules associate with the lens capsule. These findings suggest that the vasculature‐rich ciliary body is a source of lens resident immune cells. We identified a major role for these cells as rapid responders to wounding, quickly populating each wound were they can function as leaders of lens tissue repair. Our findings also show that lens resident immune cells are progenitors of myofibroblasts, which characteristically appear in response to lens cataract surgery injury, and therefore, are likely agents of lens pathologies to impair vision like fibrosis.

组织通常含有常驻免疫细胞亚群，它们作为对损伤的快速应答者发挥作用，其激活会导致适应性免疫反应的诱导，在修复和保护中起重要作用。由于晶状体是无血管组织，人们曾推测其中没有常驻免疫细胞。我们现在的研究表明，常驻免疫细胞是人类、小鼠和鸡晶状体上皮的共有特征。这些常驻免疫细胞作为对损伤的即时应答者发挥作用，并在模拟白内障手术后迅速聚集在伤口边缘，作为引导细胞发挥作用。这些常驻免疫细胞中的许多还表达MHCII，使其具有呈递抗原的能力以引发适应性免疫反应。我们提供的证据表明，在发育过程中，免疫细胞在睫状小带上迁移，并定位在晶状体赤道上皮细胞之间，靠近睫状小带与晶状体囊相连的部位。这些发现表明，富含血管的睫状体是晶状体常驻免疫细胞的一个来源。我们确定了这些细胞作为对创伤的快速应答者的主要作用，它们迅速聚集在每个伤口处，在那里它们可以作为晶状体组织修复的引导者。我们的研究结果还表明，晶状体常驻免疫细胞是肌成纤维细胞的祖细胞，肌成纤维细胞是晶状体白内障手术损伤后的典型反应产物，因此，它们可能是导致像纤维化这样损害视力的晶状体病变的因素。