Pathogenesis of lung injury mediated by lung-restricted antibodies

原发性移植物功能障碍（PGD）在肺移植后的前24-72小时内影响超过50%的受体。 移植PGD是肺移植后死亡率、移植相关多器官功能损害的主要风险。 功能障碍和慢性肺移植排斥反应。由于肺移植越来越多地被用作挽救生命的手段， 治疗慢性肺部疾病以及急性呼吸窘迫综合征，缓解PGD 是改善移植结果的多管齐下战略的关键组成部分。 在一项前瞻性临床研究中，我们发现超过30%接受肺移植的患者存在肺- 限制性自身抗体（LRA）对自身抗原，胶原V型和k-α 1微管蛋白，这是强烈的 与PGD的发展有关。既存LRA与补体激活、中性粒细胞 肺复张、PaO 2/FIO 2降低和肺损伤恶化，这些都是PGD的临床标志。在并行工作中，我们 确定了供体来源的非经典单核细胞（NCM）在肺移植物中的重要作用 灌注后PGD的发展。供体来源的NCM有义损伤相关分子模式 （DAMPs）通过TLR 2/4的冗余信号传导释放CXCL 2和其他细胞因子， 并激活供体肺泡巨噬细胞以募集受体经典单核细胞 储存在脾脏里在迁移到肺移植物时，受体经典单核细胞（CM）使肺移植物透化。 肺内皮细胞和放大的中性粒细胞外渗到肺泡腔。我们的出版和 初步数据表明，LRA，供体来源的NCM和受体来源的CM之间存在重要的相互作用， 确定肺移植后肺损伤的严重程度。具体来说，我们发现LRA结合Fc 受体，以促进它们在同种异体移植物中的保留和活化。这增强了 将CM募集到释放IL-1 β的同种异体移植物。IL-1介导的内皮细胞透化 允许LRA进入肺结核并促进中性粒细胞迁移到肺泡腔。此外，本发明还提供了一种方法， CM释放基质金属蛋白酶-8（MMP 8），其切割细胞外基质蛋白以释放 隔离自身抗原并暴露其免疫原性表位，使外渗的LRA形成 免疫复合物由此产生的免疫复合物激活补体，在第一次肺损伤时加重肺损伤。 肺移植后24小时。进一步的初步数据表明，LRA免疫复合物激活供体 衍生的NCM释放CXCL 2并通过需要Src、PI 3 K和PI 3 K的途径促进中性粒细胞募集。 BTK，但不依赖于DAMP激活的TLR 2/4/MyD 88通路，导致迟发性肺损伤。 移植后48至72小时内。我们将检验LRA与供体来源的NCM相互作用的假设， 受体CM通过补体依赖性和非依赖性途径使PGD恶化。目标1。确定 上帝抵抗军激活国家协调机制的机制。目标2.为了确定IL-1 β和MMP-8释放的作用 从受体CM切割隔离的自身抗原及其与LRA的结合。

Primary graft dysfunction (PGD) affects over 50% of recipients within the first 24-72 hours after lung transplantation. PGD is the dominant risk for post-lung transplant mortality, transplant-associated multi-organ dysfunction, and chronic lung allograft rejection. Since lung transplantation is increasingly utilized as a life-saving treatment for both chronic lung diseases as well as acute respiratory distress syndrome, mitigation of PGD represents a critical component of a multi-pronged strategy to improve transplant outcomes. In a prospective clinical study, we found that over 30% of patients undergoing lung transplantation have lung- restricted autoantibodies (LRA) against self-antigens, collagen type V and k-alpha 1 tubulin, which was strongly associated with the development of PGD. Pre-existing LRA is associated with complement activation, neutrophil recruitment, a lower PaO2/FIO2 and worsened lung injury, all clinical hallmarks of PGD. In parallel work, we identified an important role for donor derived non-classical monocytes (NCM) that are retained in the lung grafts after perfusion in the development of PGD. Donor derived NCM sense damage associated molecular patterns (DAMPs) via redundant signaling through TLR2/4 to release CXCL2 and other cytokines that directly recruit neutrophils to the allograft and activate donor alveolar macrophages to recruit recipient classical monocytes stored in the spleen. Upon migration to the lung graft, the recipient classical monocytes (CM) permeabilize the pulmonary endothelium and amplify the extravasation of neutrophils to the alveolar space. Our published and preliminary data suggest important interactions between LRA, donor derived NCM and recipient derived CM in determining the severity of lung injury after lung transplantation. Specifically, we found that LRA bind Fc receptors on donor derived NCM to promote their retention in the allograft and activation. This enhances the recruitment of CM to the allograft which release IL-1. Permeabilization of the endothelium in response to IL-1 allows LRA access to the lung interstitium and promotes neutrophil migration into the alveolar space. In addition, CM release matrix metalloproteinase-8 (MMP8), which cleaves extracellular matrix proteins to release sequestered self-antigens and expose their immunogenic epitopes, enabling the extravasated LRA to form immune complexes. The resulting immune complexes activate complement to exacerbate lung injury in the first 24 hours after lung transplantation. Further preliminary data suggest LRA immune complexes activate donor derived NCM to release CXCL2 and promote neutrophil recruitment via a pathway that requires Src, PI3K and BTK but is independent of the TLR2/4/MyD88 pathway activated by DAMPs, resulting in delayed lung injury in the 48 to 72 hours after transplant. We will test the hypothesis that LRA interact with donor derived NCM and recipient CM to worsen PGD via complement dependent and independent pathways. Aim 1. To determine the mechanisms through which LRA activate NCM. Aim 2. To determine the role of IL-1 and MMP-8 released from recipient CM in the cleavage of sequestered self-antigens and their binding to LRA.