Immune Mechanisms in Ocular Graft versus Host Disease

描述（由申请人提供）：异基因造血干细胞移植（HSCT）已成为治疗几种危及生命的血液恶性肿瘤以及某些免疫缺陷疾病的标准治疗。不幸的是，随着患有这些疾病的患者的存活率的提高，生活质量受到移植物抗宿主病（GVHD）的发展的负面影响。GVHD是一种复杂的多器官疾病，由供体同种异体反应性（allo-reactive，ALR）T细胞的免疫攻击引起， 对重要器官包括肝脏、皮肤、造血隔室和眼睛的眼表造成损害。眼部GVHD发生在>60%的这些患者中，并且特征在于干眼、结膜损伤、点状角膜病变、角膜溃疡和穿孔。患有眼部GVHD的患者由于严重的眼部不适、疼痛和视力差而遭受痛苦并丧失能力。尽管在经历GVHD的患者中眼睛受累的频率很高，但是关于引起眼部GVHD的潜在免疫机制知之甚少，这将这些患者的眼科护理限制为姑息疗法和全局抗炎药物。尽管在理解系统性GVHD中的免疫失调方面已经取得了重大进展，但该领域的关键问题是理解系统性和器官特异性GVHD之间的关系。更具体地，关于GVHD和各种组织中的后续损伤的中心未回答的问题是不仅涉及同种异体T细胞，而且涉及自体T细胞。这是相关的，因为自体免疫“类似”临床和病理症状发生在GVHD中，包括干燥综合征和干眼综合征。为了理解眼部GVHD的免疫机制，我们的小组已经开发了一种独特的临床前动物模型，其中用C57 BL 6（H2 b）T细胞+骨髓输注致死性辐照的C3H.SW小鼠（H2 b）导致全身和眼部GVHD的发展，其发病动力学与在发生眼部并发症的患者中观察到的相似。我们的初步数据清楚地表明，第一次，眼部疾病与供体T细胞在眼组织中的存在，也与巨噬细胞（M$）的浸润。重要的是，与CD 8> CD 4系统性GVHD免疫表型相反，眼隔室中的CD 4> CD 8比率免疫表型是不同的。IFN-γ和TNF-α的检测提示Th 1效应细胞和M1炎性细胞参与了眼部GVHD。有趣的是，这些小鼠也表现出胸腺损伤，因此可能涉及供体和/或宿主致病性T细胞与眼部抗原的自身反应性。基于这些结果，我们在目的1和2中提出检验以下假设：同种异体供体T细胞和/或“自体”T细胞浸润眼表面，并负责协调导致眼损伤的炎性M1 M$的募集。此外，在目标3中，我们将使用抗体/细胞因子缀合物、融合蛋白和新型小生物分子局部调节T细胞和mT，以预防和治疗眼部GVHD。

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.