T regulatory Cells in HSV Immunity and Immunopathology

描述(申请人提供)：病毒感染是否被宿主成功控制或对部分或全部个体造成显著的组织损伤是一个临床相关的问题，缺乏充分的了解。在某些情况下，损伤是病毒复制的直接后果，但更常见的情况是，宿主对病毒的反应占组织损伤的大部分甚至大部分。如果感染难以控制，这可能是广泛和长期的。许多病毒和宿主因素影响最终导致免疫或病理的事件的平衡。在病毒确实造成组织严重损伤的情况下，重要的是确定造成损伤的机制，并找到应对问题的方法。随着慢性组织破坏性病毒感染，更需要治疗性疫苗和免疫调节疗法，以改变既定的反应模式，从而将组织损伤降至最低，恢复免疫力。为了实现后一个目标，我们假设，找到一种实用的方法来扩大体内调节性T细胞的数量和功能，将是对抗病毒引起的慢性炎症反应的有价值的手段。我们之所以选择这一目标，是因为包括我们在内的许多组织过去的研究已经证实，各种类型的调节性T细胞在自身或外部抗原(包括病毒)的免疫炎症反应中发挥着有益的作用，可以限制组织损伤。这项建议的目的是评估将扩大和激活调节性T细胞(Treg)的程序，以便可以控制病毒诱导的免疫病理损害的严重程度和持续时间。我们将使用的模型是由单纯疱疹病毒(HSV)眼部感染引起的眼角膜致盲性免疫性炎症损害。这种疾病被称为间质角膜炎(SK)。实验小鼠模型反映了人类眼睛中HSV引起的类似损害，这是导致失明的重要原因。先前的研究已经证明，在小鼠模型中，SK的病变严重程度受到FoxP3 T细胞的影响，尽管Treg如何或在哪里发挥其有益影响仍不确定。计划进行实验，以验证Treg在SK发病机制不同阶段的保护作用，并评估影响SK过程中事件的Treg是否需要抗原特异性。我们还将评估这样一种假设，即增强Treg的数量和功能是一种有价值的治疗手段，最终可能转化为临床。Treg的扩展将通过使传统的NAOVE或预先承诺的非调节性T细胞转化为FoxP3和调节性功能来实现。这一目标得到了已公布和初步数据的支持，但该方法尚未得到优化，也没有使用其他策略来扩大转换后的人口并使转换后的Treg保持其调节功能。通过将抗原刺激和FTY720药物治疗(导致Treg转化)与扩展Treg并稳定其转化表型的额外操作相结合，将继续进行实验，以实现后一种目标。过去和正在进行的研究也证明，Galectin-1和Galectin-9在调节病毒诱导的免疫炎症损伤的表达方面发挥重要作用，至少部分是通过影响Treg数量和功能。实验计划进一步确定Galectins 1和Galectins 9如何在体内发挥作用，并可能用于治疗，以减轻HSV引起的组织损伤的后果。其具体目的是1论证在SK发病的哪个阶段，Treg操作会影响病毒诱导的免疫病理的表达。2开发程序，将未表达的T细胞转化和扩增为Foxp3 Treg，并显示其在抑制病毒诱导的免疫炎症损伤方面的价值。3进一步明确Galectins在SK发病机制中的作用，并确定内源性Galectins 1和外源性Galectins 9在调节病变严重程度中的作用。关键词免疫；免疫病理学：调节性T细胞；单纯疱疹病毒；间质性角膜炎；半乳糖凝集素

DESCRIPTION (provided by applicant): Whether or not a virus infection is successfully controlled by the host or causes notable tissue damage in some or all individuals is a clinically relevant issue that lacks full understanding. In some instances, injury is a direct consequence of virus replication, but more commonly the host response to the virus accounts for much or even the majority of the tissue damage. This can be extensive and prolonged if the infection is difficult to control. Many viral and host factors influence the balance of events that culminate in immunity or pathology. In circumstances where viruses do cause exuberant tissue damage, it is important to identify the mechanisms that account for the injury that occurs and develop ways to counteract the problem. With chronic tissue damaging virus infections there is more need for therapeutic vaccines and immunomodulation therapy that can redirect established response patterns so that the tissue wounding is minimized and immunity restored. To achieve this latter objective, we hypothesize that finding a practical approach to expand the number and functions of regulatory T cells in vivo will represent a valuable means to counteract chronic inflammatory reactions caused by viruses. We choose this objective because past studies by many groups, including ourselves supported by this grant, have established that regulatory T cells of various types play a beneficial role to limit tissue damage during immune inflammatory reactions to self or extrinsic antigens that include viruses. The aims of this proposal are to evaluate procedures that will expand and activate regulatory T cells (Treg) so that the severity and duration of viral induced immunopathological lesions can be controlled. The model we shall use is a blinding immunoinflammatory lesion in the cornea of the eye that results from ocular infection with the herpes simplex virus (HSV). The disease is referred as to as stromal keratitis (SK). The experimental mouse model reflects a similar lesion caused by HSV in the human eye and which is a significant cause of blindness. Prior studies had demonstrated that the lesion severity of SK in the mouse model was influenced by FoxP3+T cells, although how or where the Treg exert their beneficial influence remains uncertain. Experiments are planned to verify the protective role of Treg at various stages of SK pathogenesis and to evaluate if the Treg that influence events during SK need to be antigen specific or not. We shall also evaluate the hypothesis that enhancing the number and function of Treg represents a valuable means of therapy that could ultimately translate to the clinic. Treg expansion will be achieved by causing conventional naove or pre-committed non-regulatory T cells to convert to become FoxP3+ and regulatory in function. This objective is supported by published and preliminary data, but the approach has not been optimized, nor have additional strategies been used that expand the converted population and cause the converted Treg to sustain their regulatory function. Experiments will be pursued to achieve the latter objectives by combining the antigen stimulation and FTY720 drug treatment that causes Treg conversion with additional maneuvers that expand Treg and stabilize their converted phenotype. Past and ongoing studies also documented that galectin-1 and galectin-9 play a significant role in modulating the expression of viral induced immunoinflammatory lesions acting at least in part by affecting Treg numbers and function. Experiments are planned to further define how galectins 1 and 9 act in vivo and might be used therapeutically to diminish the consequences of HSV induced tissue damage. The specific aims are 1 To demonstrate at which stage in SK pathogenesis Treg manipulation will influence the expression of virus induced immunopathology. 2 To develop procedures that can convert and expand uncommitted T cells to become Foxp3+Treg and show the value of this to inhibit viral induced immunoinflammatory lesions. 3 To further define the participation of galectins during the pathogenesis of SK and to determine how endogenously produced and exogenously administered galectins 1 and 9 act to modulate lesion severity. Key words immunity; immunopathology: regulatory T cells; herpes simplex virus; Stromal keratitis; galectins