VIRAL PATHOGENESIS OF HIV ASSOCIATED NEPHROPATHY

HIV相关性肾病（HIVAN）是非洲肾衰竭的第三大原因。 在美国人中，慢性肾衰竭是HIV-1感染者最常见的原因，而肾脏疾病现在是这些患者死亡的第四大原因。越来越多的证据支持HIV-1感染的肾小球和肾小管上皮细胞在HIVAN发病机制中的直接作用。此外，准种分析的HIV-1包膜序列同时来自肾上皮细胞和外周血单核细胞显示肾脏特异性亚群一致的HIV-1在肾室的积极复制。在体外和转基因小鼠模型的数据表明，HIV-1基因，特别是nef，在肾上皮细胞的直接表达，可以产生表型变化和参与细胞增殖和分化的基因表达的改变，这是一致的变化与HIVAN。项目2将进一步明确肾上皮细胞感染在HIVAN发病机制中的直接作用。为了确定肾上皮感染是否可以单独解释该疾病，将检查具有肾脏疾病替代病因的HIV感染患者的肾组织。这将包括非洲裔和高加索人。组织检查将包括原位DNA PCR和上皮细胞的确证性激光解剖，并对HIV序列进行PCR扩增。为了进一步了解病毒进入这个独特的腔室，我们将通过激光捕获解剖直接从肾上皮获得的HIV-1包膜的表型特征。鉴于我们先前发表的工作和初步数据表明Nef和Vpr对足细胞的影响，我们将使用转基因小鼠模型来研究特定细胞类型中表达的单个基因产物对发病机制的贡献。通过从位点特异性启动子直接表达转基因或使用条件转基因构建体来实现靶向表达。此外，将对直接来源于肾上皮的nef序列进行基因型和表型表征，以确定独特的多态性是否与HIVAN的发生相关。拟议的研究应提供关键的 关于上皮感染在HIVAN发病机制中的作用以及HIV-1与这一独特储库的相互作用的信息，将对预防这一毁灭性并发症的治疗干预产生影响。

HIV-associated nephropathy (HIVAN) is now the third leading cause of renal failure in African Americans, the most common cause of chronic renal failure in HIV-1 infected individuals and renal disease is now the fourth leading cause of death in these patients. Accumulating evidence supports a direct role of HIV-1 infection of renal glomerular and tubule epithelial cells in HIVAN pathogenesis. Furthermore, quasispecies analysis of HIV-1 envelope sequences simultaneously derived from renal epithelial cells and peripheral blood mononuclear cells show renal-specific subclusters consistent with active replication of HIV-1 in the renal compartment. In vitro and transgenic mouse model data suggest that direct expression of HIV-1 genes, particularly nef, in renal epithelium can produce phenotypic changes and alterations in expression of cell genes involved in proliferation and differentiation that are consistent with changes associated with HIVAN. Project 2 will further define the direct role of infection of renal epithelial cells in HIVAN pathogenesis. To determine if renal epithelial infection alone can account for the disease, renal tissue will be examined from HIV-infected patients who have an alternative etiology of renal disease. This will include those of African descent as well as Caucasians. Examination of tissue will include in situ DNA PCR and confirmatory laser dissection of epithelial cells with PCR amplification of HIV sequences. To further our understanding of viral lentry into this unique compartment, we will phenotypically characterize the HIV-1 envelopes directly obtained from renal epithelium by laser capture dissection. In light of our previous published work and preliminary data demonstrating the effects of Nef and, to a lesser degree, Vpr on podocytes, we will use transgeneic mouse modeling to study the contribution of individual gene products expressed in specific cell types to pathogenesis. Targeted expression will be achieved either through direct expression of the transgene from site-specific promoters or the use of conditional transgenic constructs. Furthermore, nef sequences derived directly from renal epithelium will be genotypically and phenotypically characterized to determine if unique polymorphisms are associated with the development of HIVAN. The proposed studies should provide critical information regarding the role of epithelial infection in HIVAN pathogenesis and the interaction of HIV-1 with this unique reservoir and will impact on therapeutic interventions to prevent this devastating complication.