Immune Response to Hepatitis C in Liver Transplantation

描述（由申请人提供）：全球估计有3亿人感染丙型肝炎病毒（HCV），其中很大一部分感染者发展为肝硬化、肝功能衰竭和肝细胞癌（HCC）。这导致美国390万感染者中每年约有8-1万人死亡。因此，HCV感染已成为美国肝硬化的主要原因，对于与HCV感染相关的肝硬化患者，5年肝功能衰竭的风险约为18%，HCC的风险约为7%。因此，hcv相关性肝衰竭已成为原位肝移植（OLT）最常见的指征。因此，迫切需要更好地了解慢性HCV感染发病机制的免疫介导机制，特别是免疫功能低下的HCV感染OLT受体。本提案的具体目标是：1)定义hcv感染的OLT受体中hcv特异性CD4+和CD8+ T细胞免疫反应，以验证缺乏hcv相关的同种异体移植物损伤与抗hcv CD4+和CD8+ T细胞反应的发展相关的假设。HCV特异性CD4+和CD8+ T细胞反应将通过颗粒酶B、IFN-n和IL-5 ELISPOT分析在外周循环和移植物浸润细胞中进行评估。2)确定用于检测同种异体反应性和抗HCV反应性的免疫功能试验是否可以区分HCV复发和急性细胞排斥反应，因为这是目前在HCV感染的OLT受体管理中存在的主要问题之一。为此，将通过颗粒酶B、IFN-E和IL-5 ELISPOT检测外周血和移植物浸润淋巴细胞中CD4+和CD8+ T细胞同种异体反应性和/或hcv特异性反应性。3)定义hcv相关HCC患者的hcv特异性CD8+ T细胞免疫反应，以验证与hcv感染的HCC阴性患者相比，hcv阳性患者将表现出不同的hcv特异性CD8+ T细胞反应性的假设。这些研究还将确定在HCC细胞上表达的hcv衍生肽及其最常见的突变。本提案的总体目标是更好地定义免疫功能低下的OLT受者和HCC患者慢性HCV感染发病机制的免疫介导机制，这将有助于设计治疗这些疾病的新策略。此外，该项目旨在开发一种体外方法来区分HCV复发和OLT后的急性细胞排斥反应，这将对HCV感染的OLT接受者的管理有直接的好处。

DESCRIPTION (provided by applicant): An estimated 300 million people worldwide are infected with hepatitis C virus (HCV) and a significant percentage of infected individuals develop cirrhosis, hepatic failure and hepatocellular carcinoma (HCC). This results in approximately 8-10,000 deaths annually among the 3.9 million infected individuals in the United States. HCV infection, thus, has emerged as the leading cause of cirrhosis in the United States and for patients with established cirrhosis related to HCV infection, the 5-year risk of liver failure is approximately 18% and that of HCC is approximately 7%. Therefore, HCV-related liver failure had become the most frequent indication for orthotopic liver transplantation (OLT). Therefore, a better understanding of the immune mediated mechanisms underlying the pathogenesis of chronic HCV infection, specifically in immunocompromised HCV-infected OLT recipients is urgently needed. The specific goals of this proposal are: 1) To define HCV-specific CD4+ and CD8+ T cell immune responses in HCV-infected OLT recipients in order to test the hypothesis that the lack of HCV-related allograft injury is associated with the development of anti-HCV CD4+ and CD8+ T cell responses. HCV specific CD4+ and CD8+ T cell responses will be assessed both in the peripheral circulation and in the graft infiltrating cells by means of granzyme B, IFN-n, and IL-5 ELISPOT analyses. 2) To determine whether immune functional assays for detection of alloreactivity and anti-HCV reactivity can differentiate between HCV recurrence and acute cellular rejection, since this is one of the main problems existing today in the management of the HCV-infected OLT recipient. Towards this, the CD4+ and CD8+ T cell alloreactivity and/or HCV-specific reactivity will be determined both in peripheral blood as well as in graft-infiltration lymphocytes at the time of suspected rejection by means of granzyme B, IFN-E], and IL-5 ELISPOT assays. 3) To define HCV-specific CD8+ T cell immune responses in patients with HCV-related HCC in order to test the hypothesis that HCC-positive patients will display a different profile of HCV-specific CD8+ T cell reactivity as compared to HCV-infected HCC-negative patients. These studies will also identify the HCV-derived peptides expressed on HCC cells and their most common mutations. The overall goal of this proposal is to better define the immune mediated mechanisms underlying the pathogenesis of chronic HCV infection in immunocompromised OLT recipients and HCC patients which will aid in designing new strategies for treatment of these diseases. Further, this project is intended to develop an in vitro method for differentiating HCV recurrence and acute cellular rejection following OLT that will have immediate benefit in the management of the HCV-infected OLT recipients.