TRANSGENIC ANTIVIRALS FOR BOVINE LEUKEMIA VIRUS

描述：(改编自申请者的摘要)这条快速通道 第一阶段和第二阶段的组合应用程序的总体目标是生成 转基因牛，表达转基因牛的一种转显性衍生物 牛白血病病毒(BLV)的调控基因。调控基因来自于 BLV复制所需的REX监管区域和 产生新的传染性病毒粒子。Rex蛋白的功能是介导 病毒RNA的输出和表达，包括单剪接体和双剪接体 拼接的RNA编码Gag、Polo和env蛋白。的用法 Rex的跨支配导数的函数应阻止 成熟的原生Rex，从而抑制BLV的复制。这一点的基础 涉及与HTLV-1密切相关的肿瘤病毒的研究，以及 它的同源调控基因雷克斯。超显性Rex基因在HTLV-1中的表达 体外抑制HTLV-1复制。第一阶段应用程序的目标是 以产生高滴度、复制不合格的载体，这些载体可以提供 将BLV Rex和HTLV-1 Rex工程到细胞，从而阻止复制 体外培养。研究人员还提议将基因工程技术引入鼠MHC载体中 代表次级细胞表面抗原的I类分子 也有可能在体内产生免疫反应。的正当性 这是跨显性递送的Rex只会抑制活性复制， 然而，潜伏的前病毒不会受到影响。小鼠MHC的表达 分子将在牛身上引发免疫反应，并潜伏地摧毁 被感染的细胞。在第二阶段，申请者建议生产转基因产品 表达TD Rex基因的牛及其预防进展能力的评估 感染。由于牛的怀孕期为9个月，申请人还建议 评价转基因牛淋巴细胞对BLV的抑制作用 体外感染。此外，来自自然感染牛的淋巴细胞将 也要进行评估以确定TD Rex载体是否可以抑制病毒 体外复制。 建议的商业应用：不可用

DESCRIPTION: (Adapted from the applicant's abstract) This fast track combination Phase I and Phase II application has the overall goal of generating transgenic cattle which express the transgene for a transdominant derivative of a regulatory gene from Bovine Leukemia Virus (BLV). The regulatory gene is from the Rex regulatory region that is required for BLV replication and the generation of new infectious virions. The Rex protein functions to mediate the export and expression of viral RNA's, including singly spliced and doubly spliced RNA's that encode the gag, pol, and env proteins. The use of a transdominant derivative of Rex should function to block the function of the mature, native Rex, and thereby inhibit BLV replication. The basis for this relates to studies with the closely related oncovirus, HTLV-1, and studies with its homologous regulatory Rex gene. Transdominant Rex gene expression in HTLV-1 inhibited HTLV-1 replication in vitro. The goals of the phase I application are to generate high titer, replication incompetent vectors that can deliver the engineered BLV Rex and HTLV-1 Rex to cells, and thereby block replication in vitro. The investigators also propose to engineer into the vectors murine MHC class I molecules that will represent a secondary cell surface antigen with the potential of also generating an immune response in vivo. The justification for this is the transdominant delivered Rex will only inhibit active replication, however, latent provirus will not be affected. The expression of the murine MHC molecules will invoke an immune response in cattle and destroy the latently infected cells. In phase II, the applicants propose to produce transgenic cattle expressing TD Rex and evaluate their ability to prevent progressive infection. Since gestation in cattle is 9 months, the applicants also propose to evaluate whether lymphocytes from transgenic cattle can inhibit BLV infection in vitro. Additional, lymphocytes from naturally infected cattle will also be evaluated to determine if the TD Rex vectors can suppress viral replication in vitro. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE