Immune Mechanisms in Ocular Graft versus Host Disease

描述(申请人提供)：异基因造血干细胞移植(HSCT)已经成为治疗几种危及生命的血液系统恶性肿瘤以及某些免疫缺陷疾病的标准疗法。不幸的是，随着这些疾病患者存活率的提高，移植物抗宿主病(GVHD)的发展对患者的生活质量产生了负面影响。GVHD是一种复杂的多器官疾病，由供者异基因反应(RX)T细胞的免疫攻击引起 损害重要器官，包括肝脏、皮肤、造血室和眼睛表面。眼部移植物抗宿主病发生在这些患者中的60%，以干眼、结膜损伤、点状角膜病变、角膜溃疡和穿孔为特征。眼部GVHD患者因严重的眼睛不适、疼痛和视力低下而遭受并丧失工作能力。尽管GVHD患者眼睛受累的频率很高，但对导致眼部GVHD的潜在免疫机制知之甚少，限制了这些患者的眼科护理，仅限于姑息治疗和全球抗炎药物。尽管对系统性GVHD免疫功能失调的认识已取得重大进展，但该领域的一个关键问题是了解系统性GVHD与器官特异性GVHD之间的关系。更具体地说，关于GVHD和随后在各种组织中的损害，一个中心悬而未决的问题是，不仅allo-RX，而且自身RX T细胞也参与其中。这是相关的，因为移植物抗宿主病会出现自身免疫“类”临床和病理症状，包括干燥和干眼综合征。为了了解眼部GVHD的免疫机制，本课题组建立了一种独特的临床前动物模型，将C57BL6(H2B)T细胞+骨髓致死照射C3H.SW小鼠(H2B)，导致全身和眼部GVHD的发生，发病动力学与发生眼部并发症的患者相似。我们的初步数据首次清楚地表明，眼病与眼组织中供体T细胞的存在有关，也与巨噬细胞的渗透有关。重要的是，与CD8&GT；CD4全身性移植物抗宿主病免疫表型相比，眼房室中的CD8&GT；CD8比率免疫表型是不同的。此外，干扰素-γ和肿瘤坏死因子-α的检测表明Th1效应器allo-Rx细胞和M1炎性细胞参与了眼部移植物抗宿主病的发生。有趣的是，这些小鼠还表现出胸腺损伤，因此可能是供体和/或宿主致病T细胞对眼部抗原具有自身反应性。基于这些结果，我们在AIMS 1和AIMS 2中提出了一种假设，即allo-RX供体T细胞和/或“自身RX”T细胞都渗透到眼表，并负责协调导致眼损伤的炎性M1 m美元的募集。此外，在目标3中，我们将使用抗体/细胞因子偶联物、融合蛋白和新型生物小分子来局部调节T细胞和巨噬细胞，以预防和治疗眼部移植物抗宿主病。

DESCRIPTION (provided by applicant): Allogeneic hematopoietic stem cell transplantation (HSCT) has become the standard of care for the treatment of several life-threatening hematologic malignancies as well as certain immunodeficiency diseases. Unfortunately, as the survival rate of patients with these diseases is improved, the quality of life is negatively impacted by the development of Graft vs. Host Disease (GVHD). GVHD is a complex, multi-organ disorder arising from an immunological attack by donor allo-reactive (rx) T cells that result in damage to vital organs including the liver, skin, hematopoietic compartment and the ocular surface of the eye. Ocular GVHD occurs in >60% of these patients and is characterized by dry eye, conjunctiva damage, punctate keratopathy, corneal ulceration and perforation. Patients with ocular GVHD suffer and are incapacitated because of severe ocular discomfort, pain and poor vision. Despite the high frequency of eye involvement in patients undergoing GVHD, little is known regarding the underlying immune mechanisms responsible for ocular GVHD, limiting the ophthalmic care of these patients to palliative therapies and global anti-inflammatory drugs. Even though major advances have been made in the understanding of immune dysregulation in systemic GVHD, a critical question in the field is to understand the relationship between systemic and organ specific GVHD. More specifically, a central unanswered question regarding GVHD and subsequent damage in various tissues is the involvement of not only allo-rx, but also self-rx T cells. This is relevant as autoimmune "like" clinical and pathological symptoms occur in GVHD, including Sjogrens and dry eye syndrome. To understand the immune mechanisms of ocular GVHD, our group has developed a unique pre-clinical animal model, in which lethally irradiated C3H.SW mice (H2b) infused with C57BL6 (H2b) T cells + bone marrow, results in the development of systemic and ocular GVHD with kinetics of onset similar to that observed in patients who develop eye complications. Our preliminary data clearly demonstrate for the first time that ocular disease correlates with the presence of donor T cells in eye tissue and is also associated with the infiltration of macrophages (m$). Importantly, in contrast to the CD8>CD4 systemic GVHD immune phenotype, the CD4>CD8 ratio immune phenotype in the ocular compartment is distinct. Furthermore, the detection of IFN-y and TNF-a, suggests that Th1 effector allo-rx cells and M1 inflammatory m$ are involved in ocular GVHD. Interesting, these mice also exhibit thymic damage and therefore the possibility for the potential involvement of donor and/or host pathogenic T cells with self-reactivity to ocular antigens. Based on these results, we propose in Aims 1 and 2 to test the hypothesis that both allo-rx donor T cells and/ or "self-rx" T cells infiltrate the ocular surface and are responsible for orchestrating the recruitmet of inflammatory M1 m$ that contribute to the ocular damage. Moreover in Aim 3, we will locally regulate the T cells and m$ using antibody/cytokine conjugates, fusion proteins and novel small biomolecules to prevent and treat ocular GVHD.