VARICELLA ZOSTER VIRUS--T CELL/SKIN TROPISMS AND IMMUNIT

水痘-带状疱疹病毒（VZV）引起水痘和带状疱疹。我们的目标是提高对这种常见病原体如何引起疾病以及自然和疫苗诱导的免疫力提供的保护的认识。 糖蛋白可能是T细胞和皮肤的宿主范围决定因素，T细胞和皮肤是VZV感染期间的关键靶细胞。 我们的重点是糖蛋白，gI（ORF 67）和gE（ORF 68）。 将在体外确定在Cosmos中产生的gI或gE突变对VZV复制的影响。 将在VZV发病机制的SCIDhu小鼠模型中体内评估对人CD 4+和CD 8 + T细胞或皮肤的免疫活性，这揭示了在组织培养中完全粘附的VZV蛋白的关键作用。 还将使用绿色荧光蛋白（gfp）标记的VZV在胸腺器官培养物和II 23细胞（一种CD 4 + T细胞杂交瘤）中研究T细胞嗜性。 将在MDCK细胞中评价VZV gI和gE对上皮细胞的影响。 将疫苗株V-Oka与其亲本P-Oka进行比较，以确定gE或gI突变是否解释V-Oka减毒。 VZV感染初始宿主中的T细胞并在VZV特异性免疫被诱导之前传播。我们已经发现，VZV干扰细胞表面表达的主要组织相容性（MHC）I类和II类。 我们的目标是确定病毒的免疫调节蛋白，使VZV逃脱免疫监视，并确定皮肤归巢受体是否促进受感染的T细胞运输到皮肤。 这些机制是否在自然感染期间在皮肤部位起作用将在急性水痘病变的活检中确定。 VZV特异性T细胞应答的快速获得与轻度水痘和潜伏期的维持相关。 我们建议解决适应性VZV免疫的重要问题，新的方法来测量CD 4+和CD 8 + T细胞应答频率对显性病毒蛋白，gE和立即早期皮层/反式激活蛋白，IE62。我们将研究自然和疫苗诱导的免疫所提供的保护差异，水痘疫苗在成人中的免疫原性降低，以及VZV T细胞应答随年龄增长而下降。将使用细胞内细胞因子测定对gE和IE62蛋白和肽的CD 4+和CD 8+识别进行定量比较。 将鉴定适于合成为MHC I类和II类四聚体的肽，并用于计数CD 4+和CD 8+亚群中的VZV特异性应答T细胞。 这些VZV发病机制和免疫的平行研究与其改善水痘减毒活疫苗的实际相关性直接相关。

Varicella-zoster virus (VZV) causes varicella and herpes zoster. Our goal is to improve knowledge about how this common pathogen causes disease and about protection provided by natural and vaccine-induced immunity. Glycoproteins are likely to be host range determinants for T cells and skin, which are critical target cells during VZV infection. Our focus is on glycoproteins, gI (ORF67) and gE (ORF68). The effect of gI or gE mutations made in cosmids, on VZV replication will be determined in vitro. Infectivity for human CD4+ and CD8+ T cells or skin will be assessed in vivo in the SCIDhu mouse model of VZV pathogenesis, which reveals critical roles for VZV proteins that are completely dispensable in tissue culture. T cell tropism will also be investigated in thymic organ cultures and II23 cells, a CD4+ T cell hybridoma, using green fluorescent protein (gfp)-labeled VZV. VZV gI and gE effects on epithelial cells will be evaluated in MDCK cells. The vaccine strain, V-Oka, will be compared with its parent, P-Oka, to determine whether gE or gI mutations explain V-Oka attenuation. VZV infects T cells in the naive host and spreads before VZV specific immunity is induced. We have found that VZV interferes with cell surface expression of major histocompatibility (MHC) class I and class II. Our goals are to identify viral immunomodulatory proteins that allow VZV to escape from immune surveillance and to determine whether skin homing receptors facilitate transport of infected T cells to skin. Whether these mechanisms function at skin sites during natural infection will be determined in biopsies from acute varicella lesions. Rapid acquisition of VZV specific T cell responses correlates with mild varicella and maintenance of latency. We propose to address important questions about adaptive VZV immunity with new methods to measure CD4+ and CD8+ T cell responder frequencies against dominant viral proteins, gE and the immediate early tegument/transactivating protein, IE62. We will examine differences in protection afforded by natural and vaccine-induced immunity, diminished immunogenicity of varicella vaccine in adults, and declining VZV T cell responses with aging. Quantitative comparisons of CD4+ and CD8+ recognition of gE and IE62 protein and peptides will be made using intracellular cytokine assays. Peptides appropriate for synthesis as MHC class I and class II tetramers will be identified and used to enumerate VZV specific responder T cells in CD4+ and CD8+ subsets. These parallel investigations of VZV pathogenesis and immunity are directly linked by their practical relevance for improving live attenuated varicella vaccines.