Gene expression in non-functional CD8 T cells

描述(由申请人提供)：潜伏的疱疹病毒重新激活是免疫功能受损的人的一个特别问题，例如艾滋病患者，他们缺乏有效的CD4T辅助细胞功能。小鼠感染与人类病原体Epstein Barr病毒和Kaposi肉瘤相关疱疹病毒密切相关的小鼠伽马疱疹病毒68(MHV-68)，为研究伽玛疱疹病毒的免疫应答和检测潜在的免疫治疗药物控制病毒再激活的能力提供了有用的小动物模型。CD4T细胞缺陷小鼠可以清除MHV-68的初始挑战，但无法控制潜伏病毒，这种病毒后来在肺部重新激活。利用这种小鼠机会性感染模型，我们证明了CD40激动型抗体可以替代CD4T细胞功能，在CD4T细胞缺陷小鼠中阻止MHV-68的重新激活。我们的数据还表明，CD8+T细胞是这一效应所必需的。但CD8细胞的数量和杀伤活性无明显差异。在关联应用中，目标1中的实验旨在确定抗CD40抗体治疗是否导致CD8 T细胞功能的直接变化，或在控制病毒重新激活的另一个关键步骤中起作用，而不影响CD8 T细胞功能。我们现在已经从过继转移实验中获得了新的数据，这些数据表明，抗CD40治疗导致CD8 T细胞功能的直接变化，从而能够控制病毒的重新激活。因此，我们现在有理由开展更广泛的研究，以确定在MHV-68感染期间，CD8T细胞在抗CD40抗体治疗的CD4T细胞缺陷小鼠和对照抗体治疗的CD4T细胞缺陷小鼠中的差异。在目前的R21应用中，我们建议使用基因芯片来确定这些功能性和非功能性CD8T细胞中基因表达的差异。这些研究与R21支持机制的探索性性质是一致的，计划公告中特别提到了微阵列技术的应用。我们预计，这些分析将揭示关键调控分子或效应分子表达的差异。这将使我们深入了解抗CD40抗体治疗或CD4T细胞帮助(由CD40L介导)如何改变CD8T细胞的功能，以及CD8T细胞的功能定义是什么。这些研究将扩展和补充相关联的R01中的研究。这些数据可能会导致对CD8 T细胞如何在控制持续病毒感染中发挥作用以及CD8 T细胞激活机制的新理解。

DESCRIPTION (provided by applicant): Reactivation of latent herpesviruses is a particular problem in immunocompromised individuals such as AIDS patients who lack effective CD4 T helper cell function. Infection of mice with murine gammaherpesvirus-68 (MHV-68), which is closely related to the human pathogens Epstein Barr virus and Kaposi's sarcoma associated herpesvirus, provides a useful small animal model for studying the immune response to gamma herpesviruses and for testing the ability of potential immunotherapeutic agents to control viral reactivation. CD4 T cell deficient mice can clear an initial challenge with MHV-68, but fail to control latent virus, which later reactivates in the lungs. Using this mouse model of opportunistic infection, we showed that agonistic antibodies to CD40 could substitute for CD4 T cell function in preventing the reactivation of MHV-68 in CD4 T cell deficient mice. Our data also showed that CD8+ T cells were required for this effect. However, no difference in the number or cytolytic activity of CD8 cells was detected. In the linked application, experiments in Aim 1 were directed at determining whether anti-CD40 antibody treatment induced a direct change in the function of the CD8 T cells or acted at another essential step in the control of viral reactivation, without affecting CD8 T cell function. We have now obtained new data from adoptive transfer experiments, which show that anti-CD40 treatment induces a direct change in CD8 T cell function, enabling the control of viral reactivation. Hence we now have the justification to carry out more extensive studies to determine exactly how the CD8 T cells differ in anti-CD40 and control antibody-treated CD4 T cell-deficient mice during MHV-68 infection. In the current R21 application, we propose use gene microarrays to determine how gene expression differs in these functional and non-functional CD8 T cells. These studies are consistent with the exploratory nature of the R21 mechanism of support and the application of microarray technology is specifically cited in the Program announcement. We anticipate that the analyses will reveal differences in the expression of key regulatory or effector molecules. This will give us an insight into how CD8 T cell function is altered by the anti-CD40 antibody treatment or CD4 T cell help (mediated by CD40L) and what characteristics define a functional CD8 T cell. These studies will both extend and complement studies in the linked R01. The data are likely to lead to a new understanding of how CD8 T cells function in the control of persistent viral infections and mechanisms of CD8 T cell activation.