The role of MMP activity in T cells during influenza virus pathogenesis

描述（由申请人提供）：本申请中提出的研究将调查基质金属蛋白酶（MMP）活性在导致流感病毒免疫的T细胞迁移中起关键作用的总体假设，但高剂量或高毒性感染后的异常反应可能使T细胞衍生的MMP成为病理因素。流感病毒每年造成重大疾病和死亡，周期性流行和散发的破坏性大流行。高致病性流感病毒的有效性归因于强烈和异常的炎症反应，这可导致人类严重的免疫病理损伤和死亡，正如H5N1病毒所发现的那样。T细胞可以通过直接裂解感染细胞和产生促炎细胞因子来促进肺损伤。T细胞迁移到炎症部位及其效应反应是实现免疫的关键步骤，但也可能导致与致病菌株相关的高发病率和死亡率。我们假设T细胞有效穿过肺内皮屏障并穿过基底膜的能力是由MMPs调节的，这对T细胞的功能至关重要。MMPs具有蛋白水解能力，可介导构成基底膜的胶原网络的分裂。T细胞可以表达MMPs，这些分子的失调可能会产生深远的影响。尽管MMP活性与多种肺部疾病有关，但MMPs在调节体内T细胞对流感病毒反应中的功能尚不清楚。在本应用中，我们将研究T细胞中的MMP活性是否解释了它们在流感病毒反应中穿过肺基底膜的迁移，并因此使T细胞介导的病理发展。我们将研究不同T细胞亚群中MMP表达对其功能的相对贡献，通过过继转移由于遗传缺陷（MMP2和MMP9敲除）或抑制（通过逆转录病毒转导敲除）而缺乏MMP活性的T细胞。此外，我们将确定在体内诱导MMP表达的因素。我们将重点关注LFA/ICAM相互作用，它调节CD4/CD8 T细胞在肺中的迁移和外源性细胞因子产生的影响，因为它与病理有关。两者都能在体外诱导T细胞的MMP活性。对流感病毒发病过程中MMP在T细胞功能中的作用的新见解的发现可以阐明免疫和病理之间的平衡，因此可能具有相当大的治疗相关性。与公共卫生相关的流感病毒每年造成重大的疾病和死亡，伴有周期性的季节性流行和散发的破坏性大流行。本研究的目的是研究流感病毒感染期间免疫病理发展的基础反应。这些研究将为流感病毒免疫调节提供新的见解，并可能提供治疗临床症状的策略。

DESCRIPTION (provided by applicant): The research proposed in this application will investigate the overall hypotheses that matrix metalloprotease (MMP) activity has a critical role in the migration of T cells that leads to immunity to influenza virus, but that aberrant responses after high dose or highly virulent infections could make T cell-derived MMPs a factor in pathology. Influenza viruses cause significant annual illness and death with recurrent seasonal epidemics and sporadic devastating pandemics. The efficiency of highly pathogenic influenza viruses has been attributed to potent and aberrant inflammatory responses, which can result in severe immunopathological damage and death in humans, as found with the H5N1 virus. T cells can contribute to pulmonary damage by direct lysis of infected cells and the production of pro-inflammatory cytokines. Migration of T cells into the site of inflammation and their effector responses in situ are crucial steps towards immunity, but could also contribute to the high morbidity and mortality associated with pathogenic strains. We hypothesize that the ability of T cells to efficiently cross the lung endothelial barrier and move through the basement membrane, which is essential for their function, is regulated by MMPs. MMPs have the proteolytic capability to mediate cleavage of the collagen network that makes up the basement membrane. T cells can express MMPs and dysregulation of these molecules could have far-reaching consequences. Although, MMP activity has been implicated in a variety of pulmonary diseases, nothing is yet known regarding the function of MMPs in regulating the in vivo T cell response to influenza viruses. In this application we will investigate whether MMP activity in T cells accounts for their migration across the basement membrane of the lung in response to influenza virus and as such enables the development of T cell-mediated pathology. We will investigate the relative contribution of MMP expression in different T cell subpopulations to their function using adoptive transfers of T cells that lack MMP activity by genetic deficiency (MMP2 and MMP9 knock-out) or by inhibition (knock-down by retroviral transduction). In addition we will identify the factors that induce MMP expression in vivo. We will focus on the LFA/ICAM interaction, which regulates CD4/CD8 T cell migration in the lung and the effects of extrinsic cytokine production, since it is associated with pathology. Both can elicit MMP activity in T cells ex vivo. The discovery of new insights into the role(s) of MMP in T cell function during influenza virus pathogenesis could elucidate the balance between immunity and pathology and may therefore have considerable therapeutic relevance. PUBLIC HEALTH RELEVANCE Influenza viruses cause significant annual illness and death with recurrent seasonal epidemics and sporadic devastating pandemics. The goal of the proposed research is to investigate the responses that underlie the development of immunopathology during influenza virus infection. These studies will provide new insights into the regulation of immunity to influenza viruses and might offer a strategy to treat clinical symptoms.