Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.
Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, China.
Invest Ophthalmol Vis Sci. 2024 Jan 2;65(1):40. doi: 10.1167/iovs.65.1.40.
To evaluate whether fibrosis contributes to corneal transplant failure and to determine whether effector CD4+ T cells, the key immune cells in corneal transplant rejection, play a direct role in fibrosis formation.
Allogeneic corneal transplantation was performed in mice. Graft opacity was evaluated by slit-lamp biomicroscopy, and fibrosis was assessed by in vivo confocal microscopy. Expression of alpha-smooth muscle actin (α-SMA) in both accepted and failed grafts was assessed by real-time PCR and immunohistochemistry. Frequencies of graft-infiltrating CD4+ T cells, neutrophils, and macrophages were assessed using flow cytometry. In vitro, MK/T-1 corneal fibroblasts were co-cultured with activated CD4+CD25- effector T cells isolated from corneal transplant recipient mice, and α-SMA expression was quantified by real-time PCR and ELISA. Neutralizing antibody was used to evaluate the role of interferon gamma (IFN-γ) in promoting α-SMA expression.
The majority of failed grafts demonstrated clinical signs of fibrosis which became most evident at week 6 after corneal transplantation. Failed grafts showed higher expression of α-SMA as compared to accepted grafts. Flow cytometry analysis showed a significant increase in CD4+ T cells in failed grafts compared to accepted grafts. Co-culture of activated CD4+CD25- effector T cells with corneal fibroblasts led to an increase in α-SMA expression by fibroblasts. Inhibition of IFN-γ in culture significantly suppressed this increase in α-SMA expression as compared to immunoglobulin G control.
Fibrosis contributes to graft opacity in corneal transplant failure and is mediated at least in part by effector CD4+ T cells via IFN-γ.
评估纤维化是否导致角膜移植失败，并确定在角膜移植排斥反应中起关键作用的效应性 CD4+T 细胞是否直接参与纤维化的形成。
在小鼠中进行同种异体角膜移植。通过裂隙灯生物显微镜评估移植物混浊度，并通过体内共聚焦显微镜评估纤维化。通过实时 PCR 和免疫组织化学评估接受和失败移植物中α-平滑肌肌动蛋白（α-SMA）的表达。使用流式细胞术评估移植部位浸润的 CD4+T 细胞、中性粒细胞和巨噬细胞的频率。在体外，将 MK/T-1 角膜成纤维细胞与从角膜移植受鼠分离的活化的 CD4+CD25-效应 T 细胞共培养，并通过实时 PCR 和 ELISA 定量测定α-SMA 的表达。使用中和抗体评估干扰素γ（IFN-γ）在促进α-SMA 表达中的作用。
大多数失败的移植物表现出纤维化的临床迹象，这在角膜移植后 6 周最为明显。与接受的移植物相比，失败的移植物表现出更高的α-SMA 表达。流式细胞术分析显示，与接受的移植物相比，失败的移植物中 CD4+T 细胞显著增加。将活化的 CD4+CD25-效应 T 细胞与角膜成纤维细胞共培养会导致成纤维细胞中α-SMA 表达增加。与 IgG 对照相比，在培养物中抑制 IFN-γ可显著抑制这种α-SMA 表达的增加。
纤维化导致角膜移植失败中的移植物混浊，至少部分是通过 IFN-γ介导的效应性 CD4+T 细胞介导的。
Zotero 插件
