Role of MHV68 v-cyclin in virus egress

描述（由申请人提供）：伽玛疱疹病毒与淋巴增生性疾病和淋巴瘤的发展有关，特别是在免疫抑制个体中。事实上，在艾滋病毒感染者中出现的一半淋巴瘤与EBV或KSHV感染有关。扰乱宿主细胞周期是DNA病毒实现有利于病毒生长的细胞环境的常用策略。腺病毒、多瘤病毒、乳头状瘤病毒和许多疱疹病毒编码直接改变宿主细胞周期的基因，或与宿主基因产物相互作用到同一目的。γ - 2疱疹病毒，如卡波西肉瘤相关疱疹病毒（KSHV）、猴疱疹病毒（HVS）和鼠γ -疱疹病毒-68 (MHV68)，编码哺乳动物d型细胞周期蛋白的同源物。我们之前已经证明MHV68 v-cyclin需要：(i)在小鼠肺中有效的急性复制；（ii）潜伏感染巨噬细胞和B细胞的再激活。我们最近确定了一个组织培养模型，该模型概括了在体内观察到的v-cyclin null和v-cyclin CDK结合突变体的复制缺陷。在组织培养模型中对MHV68复制的进一步表征已经确定了v-cyclin null和v-cyclin CDK结合突变体从感染细胞中输出的深刻缺陷。在这个

DESCRIPTION (provided by applicant): Gammaherpesviruses are associated with the development of lympho-proliferative disorders and lymphoma, particularly in immunosuppressed individuals. Indeed, half of the lymphomas that arise in HIV infected individuals are associated with either EBV or KSHV infection. Perturbation of host cell cycle is a common strategy employed by DNA viruses to achieve a cellular environment conducive to viral growth. Adenovirus, polyoma virus, papilloma virus, and many herpesviruses encode genes that directly alter the host cell cycle, or interact with host gene products to the same end. Rhadinoviruses (γ2-herpesviruses), such as Kaposi sarcoma-associated herpesvirus (KSHV), herpesvirus saimiri (HVS), and murine gammaherpesvirus-68 (MHV68), encode a homolog of mammalian D-type cyclins. We have previously shown that the MHV68 v-cyclin is required for: (i) efficient acute replication in the lungs of mice; and (ii) reactivation from latently infected macrophages and B cells. We have recently identified a tissue culture model that recapitulates the replication defect observed with v-cyclin null and v-cyclin CDK binding mutants in vivo. Further characterization of MHV68 replication in this tissue culture model has identified a profound defect in the egress of v-cyclin null and v-cyclin CDK binding mutants from infected cells. In this new R21 application, we propose to investigate the role that the MHV68 v-cyclin plays in virus egress/release from lung epithelial cells. The specific aims are as follows: Aim 1. Characterization of the v-cyclin null mutant MHV68 egress phenotype: 1.a Localization of virions in wt and v-cyclin mutant infected cells; 1.b Cellular localization of v-cyclin during virus infecton; 1.c Assess egress phenotype of a KSHV v-cyclin null mutant in HUVECs. Aim 2. Analysis of v-cyclin functions in the absence of MHV68 infection: 2.a Generate and characterize inducible v-cyclin expressing cell lines; 2.b Identify v-cyclin interacting partners.