Experimental Uveal Melanoma and Ocular Immune Privilege

葡萄膜黑色素瘤是成人最常见的原发性恶性眼内肿瘤。肝脏转移性疾病是葡萄膜黑色素瘤患者死亡的主要原因，目前没有有效的治疗方法。葡萄膜黑色素瘤的开发和测试治疗一直受到阻碍，缺乏一个令人满意的动物模型，其中葡萄膜黑色素细胞原位转化和转移到肝脏。此外，很少有眼部来源的小鼠黑色素瘤细胞系可用于旨在了解葡萄膜黑色素瘤的免疫逃避和肝转移机制的研究。本提案的目的是开发具有允许在Cre重组酶存在下通过酪氨酸酶启动子诱导表达SV 40 Tag的元件的SV 40 T抗原（Tag）转基因。该转基因将允许C57 BI/6小鼠中的色素组织（包括黑素细胞）的诱导性原位转化，通过靶向药物递送到眼睛的前段或后段中以诱导Cre重组酶活性。这些小鼠将用于通过监测SV 40标签特异性免疫应答来表征对原发性和转移性葡萄膜黑色素瘤的免疫应答。 免疫反应。对SV 40标签的免疫应答在C57 BI/6小鼠中得到充分表征， 由可溶性MHC I类：SV 40标签肽组成的四聚体可与SV 40标签沿着获得 特异性TCR转基因株用于旨在确定原发性和转移性葡萄膜黑色素瘤中CD 8+肿瘤特异性T细胞的命运的研究。此外，这些SV 40标签转基因小鼠将是产生葡萄膜黑色素瘤细胞系的来源。由于酪氨酸酶启动子在皮肤黑素细胞中也有活性，因此该转基因小鼠品系也可用作皮肤黑色素瘤的模型，其可通过药物递送至皮肤来诱导。来自SV 40 Tag转基因小鼠的葡萄膜和皮肤黑色素瘤细胞系的比较可能揭示控制免疫逃避和与葡萄膜相关的肝转移而不是皮肤黑色素瘤的新分子。了解葡萄膜黑色素瘤的免疫逃避机制可能会导致促进肿瘤消除的治疗方法。此外，这些免疫抑制机制的操作可用于抑制T细胞应答以延长眼内的移植物移植，例如RPE移植，或减轻T细胞介导的自身免疫性葡萄膜炎。

DESCRIPTION: Uveal melanoma is the most common primary malignant intraocular tumor in adults. Metastatic disease of the liver is the leading cause of death in uveal melanoma patients and there is currently no effective treatment. Developing and testing therapies for uveal melanoma has been hampered by the absence of a satisfactory animal model in which uveal melanocytes are transformed in situ and metastasize to the liver. In addition, few murine melanoma cell lines of ocular origin are available for studies aimed at understanding the mechanisms of immune evasion and liver metastasis by uveal melanoma. The objective of this proposal is to develop an SV40 T-antigen (Tag) transgene with elements that allow inducible expression of SV40 Tag by the tyrosinase promoter in the presence of Cre-recombinase. This transgene will permit inducible in situ transformation of pigmented tissues, including melanocytes, in C57BI/6 mice, by targeted drug delivery into the anterior or posterior segments of the eye to induce Cre-recombinase activity. These mice will be used to characterize the immune response to primary and metastatic uveal melanoma by monitoring SV40 Tag-specific immune responses. The immune response to SV40 Tag is well characterized in C57BI/6 mice and tetramers composed of soluble MHC Class I : SV40 Tag peptides are available along with an SV40 Tag specific TCR transgenic strain for studies aimed at determining the fate of CD8+ tumor-specific T cells in primary and metastatic uveal melanoma. In addition, these SV40 Tag transgenic mice will be a source for generating uveal melanoma cell lines. As the tyrosinase promoter is also active in cutaneous melanocytes, this transgenic mouse strain may also serve as a model of cutaneous melanoma which is inducible by drug delivery to the skin. Comparison of uveal and cutaneous melanoma cell lines derived from SV40 Tag transgenic mice may reveal novel molecules that control immune evasion and liver metastasis associated with uveal but not cutaneous melanoma. Understanding the mechanisms of immune evasion by uveal melanomas may lead to therapeutic approaches to promote tumor elimination. Furthermore, manipulation of these immune-suppressive mechanisms may be employed to inhibit T cell responses to prolong graft transplantation in the eye, for example, RPE transplants, or mitigate T cell mediated autoimmune uveitis.