IN VITRO NEUTRALIZATION OF HCV WITH MONOCLONAL ANTIBODIES BEFORE ADMINISTRATION

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。在接触过丙型肝炎病毒的人中，大约85%的人会慢性感染丙型肝炎病毒。目前，美国估计有270万慢性感染者，全球估计有2亿人。目前还没有疫苗，慢性丙型肝炎病毒感染的治疗仅限于干扰素和利巴韦林的组合，但治疗成功的患者不到一半。出于这些原因，接种疫苗和/或免疫疗法可能是一种重要的替代方案。丙型肝炎病毒的包膜蛋白显然是任何丙型肝炎疫苗的靶标。不幸的是，由于病毒的细胞培养系统很差，经典的使用抗体的体外中和试验不能使用传染性病毒进行。另一种测试抗体中和潜力的方法是在体外将丙型肝炎病毒与抗体结合过夜，然后通过接种到黑猩猩身上来测试病毒的灭活情况。最近，人类免疫缺陷病毒-丙型肝炎病毒假型颗粒被开发出来，可以在不使用动物模型的情况下，在体外测试抗体的中和能力。然而，需要确定的是，假型颗粒确实代表了真实的丙型肝炎病毒颗粒，并且中和这些假型颗粒的抗体也使用体内系统来中和丙型肝炎病毒。确定这一点的唯一方法是将体外中和伪型的单抗与以黑猩猩为读数的体外中和试验进行比较。本研究旨在对这一现象进行比较。如果建立了确切的相关性，黑猩猩确定中和抗体的需求将大大减少。将100只黑猩猩感染剂量的丙型肝炎病毒单抗分别与4株单抗在体外过夜结合。孵化后，将混合后的混合物静脉接种。变成了黑猩猩。(总容量约为5毫升)。动物每周都会被放血，并监测丙型肝炎病毒血症。如果8周后没有感染迹象，动物将被未中和的丙型肝炎病毒攻击，以证明其传染性。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Hepatitis C virus infections in man become chronic in approximately 85% percent of individuals exposed. At present there are an estimated 2.7 million chronically infected people in the United States and an estimated 200 million worldwide. There is no vaccine and therapy for chronic HCV infections is limited a combination of interferon and ribavirin, but treatment is successful in less than half the patients. For these reasons, vaccination and/or immuno-therapy may be an important alternative. The envelope proteins of HCV are an obvious target for any HCV vaccine. Unfortunately, due to poor cell culture systems for the virus, classic in vitro neutralization tests using antibodies cannot be performed using infectious virus. An alternative method to test the neutralization potential of an antibody is to combine HCV and antibody in vitro overnight and then test the inactivation of the virus by inoculation into chimpanzees. Recently, HIV-HCV pseudotype particles were developed that can be potentially used to test the neutralizing capabilities of antibodies in vitro without the use of an animal model. However, it needs to be established that the pseudotype particles do represent authentic HCV particles and that antibodies that neutralize these pseudotype particles also neutralize HCV using an in vivo system. The only way to establish this is through a comparison of monoclonal antibodies shown to neutralize pseudotypes in vitro with an in vitro neutralization test using the chimpanzee as a read-out. This study aims to make this comparison. If a firm correlation is established the need for chimpanzees to determine neutralizing antibodies will be greatly reduced. 100 chimpanzee infectious doses of monoclonal HCV will be combined with each of 4 monoclonal antibodies in vitro overnight. Following incubation the combined mixtures will be inoculated i.v. into chimpanzees. (Total volume approx 5ml). Animals will be bled weekly and monitored for HCV viremia. If no infection is indicated after 8 weeks the animals will be challenged with un-neutralized HCV to demonstrate infectivity.