Hua Jing, Stevenson William, Dohlman Thomas H, Inomata Takenori, Tahvildari Maryam, Calcagno Narghes, Pirmadjid Negar, Sadrai Zahra, Chauhan Sunil K, Dana Reza
Invest Ophthalmol Vis Sci. 2016 Mar;57(3):1457-67. doi: 10.1167/iovs.15-17551.
The graft site microenvironment has a profound effect on alloimmunity and graft survival. We aimed to study the kinetics and phenotype of trafficking antigen-presenting cells (APC) to the draining lymph nodes (DLNs) in a mouse model of corneal transplantation, and to evaluate the homing mechanisms through which graft site inflammation controls APC trafficking.
Allogeneic donor corneas were transplanted onto inflamed or quiescent graft beds. Host- (YAe+) and donor (CD45.1+ or eGFP+)-derived APCs were analyzed by flow cytometry. Protein and mRNA expression of the CC chemokine receptor (CCR)7 ligands CCL19 and CCL21 were assessed using ELISA and Real-Time qPCR, respectively. Transwell migration assay was performed to assess the effect of DLNs isolated from hosts with inflamed graft beds on mature bone marrow-derived dendritic cells (BMDCs).
We found that inflamed graft sites greatly promote the trafficking of both recipient- and graft-derived APCs, in particular mature CCR7+ CD11c+ dendritic cells (DC). CCL19 and CCL21 were expressed at significantly higher levels in the DLNs of recipients with inflamed graft beds. The supernatant of DLNs from recipients with inflamed graft beds induced a marked increase in mature DC migration compared with supernatant from recipients with quiescent graft beds in a transwell assay. This effect was abolished by neutralizing CCL19 or CCL21. These data suggest that graft site inflammation increases the expression of CCR7 ligands in the DLNs, which promote mature DC homing and allorejection.
We conclude that the graft site microenvironment plays a critical role in alloimmunity by determining DC trafficking through the CCR7-CCL19/21 axis.
移植部位的微环境对同种异体免疫和移植物存活具有深远影响。我们旨在研究在角膜移植小鼠模型中，抗原呈递细胞（APC）向引流淋巴结（DLN）迁移的动力学和表型，并评估移植部位炎症控制APC迁移的归巢机制。
将同种异体供体角膜移植到炎症或静止的移植床。通过流式细胞术分析宿主来源（YAe+）和供体来源（CD45.1+或eGFP+）的APC。分别使用酶联免疫吸附测定（ELISA）和实时定量聚合酶链反应（Real-Time qPCR）评估CC趋化因子受体（CCR）7配体CCL19和CCL21的蛋白质和mRNA表达。进行Transwell迁移试验，以评估从炎症移植床宿主分离的DLN对成熟骨髓来源树突状细胞（BMDC）的影响。
我们发现炎症移植部位极大地促进了受体来源和移植物来源的APC的迁移，特别是成熟的CCR7+ CD11c+树突状细胞（DC）。在炎症移植床受体的DLN中，CCL19和CCL21的表达水平显著更高。在Transwell试验中，与静止移植床受体的上清液相比，炎症移植床受体的DLN上清液诱导成熟DC迁移显著增加。通过中和CCL19或CCL21可消除这种作用。这些数据表明移植部位炎症增加了DLN中CCR7配体的表达，促进了成熟DC归巢和同种异体排斥反应。
我们得出结论，移植部位微环境通过CCR7-CCL19/21轴决定DC迁移，在同种异体免疫中起关键作用。
