Background

Chronic lung allograft dysfunction in lung transplant recipients (LTxRs) has 2 phenotypes: obstructive bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). Our goal was to define distinct immunologic markers of exosomes from LTxRs with BOS or RAS.

Methods

Plasma was collected from LTxRs with BOS (n = 18), RAS (n = 13), and from stable LTxRs (n = 5). Antibodies to lung self-antigens (SAgs) were determined by ELISA. Exosomes were isolated by ultracentrifugation. Donor specific antibodies to HLA were quantified using Luminex. Exosomes were characterized for lung SAgs, transcription factors, 20S proteasome, HLA class I and II, and polymeric immunoglobulin receptor protein using western blot. Exosome miRNA was analyzed using NanoString. The exosome-induced immune response was determined in mice.

Results

LTxRs with RAS, but not BOS, had donor specific antibodies at diagnosis. CIITA, NFkB, polymeric immunoglobulin receptor protein, 20S proteasome, HLA-DQ, and HLA-DR were significantly higher in RAS exosomes than in BOS exosomes. RAS plasma had high levels of proinflammatory cytokines and distinct exosomal miRNA. Immunization of C57BL/6 mice with RAS exosomes showed severe inflammation and peribronchial fibrosis, whereas BOS exosomes induced patchy inflammation and fibrosis.

Conclusion

LTxRs with BOS or RAS had exosomes with distinct molecular and immunologic profiles. RAS samples had a higher concentration of proinflammatory factors, HLA class II, lung SAgs, and antibodies to HLA class II molecules, indicating severe allograft injury. Mice immunized with RAS exosomes developed lesions in airways, pleura, interlobular septum, and alveoli, whereas BOS exosomes induced mild to patchy inflammation with lung fibrosis.

中文翻译：

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限制性同种异体移植综合征与闭塞性细支气管炎综合征：循环外泌体的免疫学和分子特征

背景

肺移植受者的慢性同种异体移植物功能障碍 (LTxRs) 有 2 种表型：阻塞性闭塞性细支气管炎综合征 (BOS) 和限制性同种异体移植物综合征 (RAS)。我们的目标是从具有 BOS 或 RAS 的 LTxR 中定义不同的外泌体免疫标志物。

方法

从具有 BOS ( n = 18)、RAS ( n = 13) 的 LTxRs 和从稳定的 LTxRs ( n = 5) 收集血浆。通过ELISA确定针对肺自身抗原（SAgs）的抗体。通过超速离心分离外泌体。使用 Luminex对 HLA 的供体特异性抗体进行量化。使用蛋白质印迹对外泌体的肺 SAg、转录因子、20S 蛋白酶体、HLA I 类和 II 类以及聚合免疫球蛋白受体蛋白进行了表征。使用 NanoString 分析外泌体miRNA。在小鼠中测定了外泌体诱导的免疫反应。

结果

具有 RAS 而不是 BOS 的 LTxR 在诊断时具有供体特异性抗体。RAS外泌体中的CIITA、NFkB、聚合免疫球蛋白受体蛋白、20S蛋白酶体、HLA-DQ和HLA-DR显着高于BOS外泌体。RAS血浆具有高水平的促炎细胞因子和独特的外泌体miRNA。用 RAS 外泌体免疫 C57BL/6 小鼠显示出严重的炎症和支气管周围纤维化，而 BOS 外泌体诱导斑片状炎症和纤维化。

结论

具有 BOS 或 RAS 的 LTxR 具有具有不同分子和免疫学特征的外泌体。RAS 样本具有较高浓度的促炎因子、HLA II 类、肺​​ SAgs 和 HLA II 类分子抗体，表明同种异体移植物损伤严重。用 RAS 外泌体免疫的小鼠在气道、胸膜、小叶间隔和肺泡中出现病变，而 BOS 外泌体诱导轻度至斑片状炎症并伴有肺纤维化。