Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
Am J Transplant. 2013 Jun;13(6):1461-73. doi: 10.1111/ajt.12228. Epub 2013 Apr 22.
Keratoplasty is the primary treatment to cure blindness due to corneal opacification. However, immune-mediated rejection remains the leading cause of keratoplasty failure. Here, we utilize an in vivo imaging approach to monitor, track, and characterize in real-time the recruitment of GFP-labeled allo-specific activated (Bonzo) T cells during corneal allograft rejection. We show that the recruitment of effector T cells to the site of transplantation determined the fate of corneal allografts, and that local intra-graft production of CCL5 and CXCL9/10 regulated motility patterns of effector T cells in situ, and correlated with allograft rejection. We also show that different motility patterns associate with distinct in vivo phenotypes (round, elongated, and ruffled) of graft-infiltrating effector T cells with varying proportions during progression of rejection. The ruffled phenotype was characteristic of activated effectors T cells and predominated during ongoing rejection, which associated with significantly increased T cell dynamics within the allografts. Importantly, CCR5/CXCR3 blockade decreased the motility, size, and number of infiltrating T cells and significantly prolonged allograft survival. Our findings indicate that chemokines produced locally within corneal allografts play an important role in the in situ activation and dynamic behavior of infiltrating effector T cells, and may guide targeted interventions to promote graft survival.
角膜移植术是治疗角膜混浊导致失明的主要方法。然而，免疫介导的排斥反应仍然是角膜移植失败的主要原因。在这里，我们利用体内成像方法来实时监测、跟踪和描述 GFP 标记的同种异体激活（Bonzo）T 细胞在角膜同种异体移植排斥反应过程中的募集情况。我们发现效应 T 细胞向移植部位的募集决定了角膜同种异体移植物的命运，而局部移植内 CCL5 和 CXCL9/10 的产生调节了效应 T 细胞在原位的运动模式，并与同种异体移植排斥反应相关。我们还发现，不同的运动模式与排斥反应进展过程中不同比例的浸润效应 T 细胞具有不同的体内表型（圆形、细长形和皱褶形）相关。皱褶形表型是活化效应 T 细胞的特征，在持续排斥反应中占主导地位，这与同种异体移植物内 T 细胞的动态明显增加有关。重要的是，CCR5/CXCR3 阻断减少了浸润 T 细胞的运动性、大小和数量，并显著延长了移植物的存活时间。我们的研究结果表明，角膜同种异体移植物内局部产生的趋化因子在浸润效应 T 细胞的原位激活和动态行为中发挥重要作用，并可能指导靶向干预以促进移植物存活。
