Bioinformatic Mapping of HIV-1 Nef Manipulation of T-Cell Activation and Function

描述（由申请人提供）：HIV疾病的特征是CD8+ T细胞高水平活化和T细胞功能受损。尽管这是HIV-1感染的显著特征，但人类CD8+ T细胞活化变异的基础尚不清楚。HIV-1流行毒株的变异可能解释了这种变异。我们打算在HIV-1 Nef蛋白内绘制T细胞活化的病毒遗传决定因素。HIV-1 Nef蛋白多次被认为与人体免疫系统的操纵有关。HIV-1 Nef具有非常广泛的功能，下调关键表面受体（如CD4、CD28和MHC）的表达，促进病毒进入和释放，直接与信号蛋白（如T细胞受体近端激酶Lck）相互作用，诱导IL-2表达。网站c

DESCRIPTION (provided by applicant): HIV disease is characterized by high level CD8+ T cell activation and impairment in T cell function. Despite being the distinguishing characteristic of HIV-1 infection, the basis for the variation in CD8+ T cell activation in humans is not well understood. Variation in circulating strains of HIV-1 may account for this variation. We intend to map viral genetic determinants of T cell activation within the HIV-1 Nef protein. The HIV-1 Nef protein has been repeatedly implicated in manipulation of the human immune system. Adopting a very wide array of functions, HIV-1 Nef down modulates expression of key surface receptors, such as CD4, CD28, and MHC, facilitates viral entry and release, directly interacts with signaling proteins, such as the T cell receptor proximal kinase, Lck, and induce IL-2 expression. The sites c onferring these functions to Nef fall in distinct regions of the protein - regions which vary in sequence across HIV-1 strains. Nef is expressed early in infection, and is a target for CTL immune escape. HIV-1 Nef activity within infected CD4+ T cells influences cellular response to stimuli, cytokine secretion patterns, and interaction with CD8+ T cells. In this way, Nef may influence CD8+ T cell activation levels and T cell maturation. While Nef has been studied extensively in vitro, the impact of Nef sequence variation in vivo has not been well studied. We propose to relate HIV-1 viral nef sequence to T cell activation levels, T cell phenotype, and T cell signaling alterations by use of advanced bioinformatic mapping tools. We will perform these studies in a cohort of 220 recently HIV-1 infected adults with well-characterized disease course and in collaboration with the UCSF/CFAR Core Immunology Laboratory and the UCSF Laboratory of Clinical Virology. We will use tree- structured biostatistical methods and their extensions which are well suited to handling of high-dimensional biological data types, such as genetic sequence and flow cytometry. The strengths of this application include the availability of specimens from a well-characterized cohort of HIV-1 infected adults; the use of advanced bioinformatic mapping tools; high-dimensional flow cytometric measures of function and signaling; a highly qualified inter-disciplinary research team; and a longitudinal approach to study of a genetically diverse entity, HIV-1. This work will facilitate development of therapies to improve the effectiveness of T cell responses and design of an effective HIV vaccine. HIV disease is characterized by high level CD8+ T cell activation and impairment in T cell function. Despite being the distinguishing characteristic of HIV-1 infection, the basis for the variation in CD8+ T cell activation in humans is not well understood. Variation in circulating strains of HIV-1 may account for this variation. We intend to map viral genetic determinants of T cell activation within the HIV-1 Nef protein.