HCV in Alcoholics

描述（由申请人提供）：慢性丙型肝炎（HCV）感染是酗酒者肝脏疾病、肝硬化和肝细胞癌（HCC）的主要原因。虽然已经确定慢性酗酒者CV感染的发病率很高，但这些高发病率的原因尚不清楚，但可能部分与乙醇对病毒结构和非结构蛋白的体液和细胞免疫反应的影响有关。过去的研究表明，在小鼠模型中长期乙醇喂养对作为免疫原的HCV核心和NS 5蛋白产生病毒特异性CD 4+和CD 8 + T细胞活性具有深刻的抑制作用。更重要的是，乙醇的这种抑制作用通过在基因免疫后与IL 2或GM-CSF表达质粒共免疫而完全逆转，这表明树突状细胞（DC）可能参与这些异常免疫应答，因此，在CD 4+和CD 8+细胞本身中可能不存在内在异常。我们建立了一个实验模型系统，研究慢性乙醇消耗对在受控条件下体内产生的DC功能的影响。这种方法使我们能够表征乙醇对DC的细胞表面标志物、细胞因子谱、抗原呈递能力和内吞能力的影响。此外，我们评估了随后的作用，DC功能障碍的产生细胞毒性T淋巴细胞（CTL）的免疫反应后，基因免疫与表达NS 5蛋白的质粒，通过使用过继转移的同基因DC。体内DC的产生结合同基因DC转移和基于DMA的免疫显示，乙醇诱导的DC功能障碍是负责降低对HCV的细胞免疫应答的主要因素。这一发现可能与酗酒者的持续HCV感染有关，并确定了一种具有乙醇效应风险的关键细胞类型。该建议的中心假设是，改变DC功能是乙醇产生的主要免疫学变化之一，慢性乙醇对DC亚群可能有不同的影响，随后损害病毒清除所需的细胞免疫应答。因此，我们希望开发和实施增加乙醇消耗宿主产生更好的抗病毒应答的能力的策略。我们计划做以下工作：具体目标1：评估DC在慢性乙醇喂养小鼠中对HCV的免疫应答中的作用。目的二：探索慢性乙醇暴露条件下特异性病毒抗原靶向激活DCs的两种新途径。具体目标3。描述由乙醇产生的DC功能障碍的可能遗传机制。这些研究开辟了新的途径，以提高抗病毒免疫反应的设置慢性酒精消费，通过改善DC功能。

DESCRIPTION (provided by applicant): Chronic hepatitis C (HCV) infection is a major cause of liver disease, cirrhosis, and hepatocellular carcinoma (HCC) in alcoholics. Although it has been established that chronic alcoholics have a high incidence of CV infection, the reasons for these high rates are unknown but may partially relate to the effects of ethanol on the humoral and cellular immune responses to viral structural and non-structural proteins. Past studies revealed that chronic ethanol feeding in a murine model has a profound inhibitory effect on the generation of viral-specific CD4+ and CD8+ T-cell activity to HCV core and NS5 proteins used as the immunogens. More important, this inhibitory effect of ethanol was completely reversed by co-immunization with an IL2 or GM- CSF expression plasmids following genetic immunization suggesting that dendritic cells (DCs) could be involved in these abnormal immune responses and thus, there may not be intrinsic abnormalities in CD4+ and CD8+ cells per se. We have established an experimental model system to study the effects of chronic ethanol consumption on DC function generated in vivo under controlled conditions. This approach allowed us to characterize ethanol's effect on DCs with respect to cell surface markers, cytokine profiles, antigen presentation ability, and endocytosis capacity. Furthermore, we evaluated the subsequent role of DC dysfunction in the generation of cytotoxic T-lymphocytes (CTL) immune responses following genetic immunization with a plasmid expressing NS5 protein by using adoptive transfer of syngeneic DCs. In vivo generation of DCs combined with syngeneic DC transfer and DMA-based immunization revealed that ethanol induced dysfunction of DCs is the major factor responsible for the reduce cellular immune response to HCV. This finding may have relevance to persistent HCV infection in alcoholics and identifies a critical cell type that is at risk for ethanol effects. The central hypothesis in this proposal is that altered DC function is one of the major immunologic changes produced by ethanol and there may be differential effects of chronic ethanol on DC subpopulations which subsequently impairs the cellular immune response necessary for viral clearance. Therefore, we would like to develop and implement strategies that increase the ability of the ethanol consuming host to generate better anti-viral responses. We plan to do the following: Specific Aim 1: Evaluate the role of DCs on immune responses to HCV in chronic ethanol-fed mice. Specific Aim 2: Explore two new approaches of specific viral antigen targeting to activate DCs in vivo during chronic ethanol exposure. Specific Aim 3. Characterize the possible genetic mechanisms responsible for DC dysfunction produced by ethanol. These investigations open new avenues to enhance antiviral immune response in the setting of chronic ethanol consumption by improving DC function.