Oral and Vaginal Gene Expression by Candida During AIDS

描述(申请人提供)：口咽和外阴阴道念珠菌病(OPC和VVC)，由白色念珠菌引起的粘膜感染，是艾滋病毒感染者中主要的机会性感染。在大多数人类中，白色念珠菌是胃肠道的一种无害的共生体。生物体转变为侵袭性病原体的机制还知之甚少。我们假设口腔和阴道粘膜的发病机制是由黏膜表面特异的念珠菌基因亚集的表达促进的。我们实验室的主要总体目标是了解白色念珠菌在人类感染发病机制中的基因表达。该R21项目的目标是确定在口腔和/或阴道粘膜中特异表达的白色念珠菌基因，以确定与HIV相关性念珠菌病发病有关的基因。为了做到这一点，我们将使用唾液和阴道液来鉴定免疫原性白念珠菌抗原，这些唾液和阴道液中含有丰富的本地产生的抗念珠菌抗体。在初步研究中，我们分别从患有活动性OPC和VVC的HIV感染者那里创建了单独的唾液和阴道液池。将汇集的样品吸附在体外培养的白色念珠菌菌株的酵母和菌丝上，以及细胞裂解物上。在特定的目标1中，我们将使用吸附的样本，现在集中在针对人类宿主内唯一表达的抗原的抗体中，以并行地筛选白色念珠菌基因组表达文库。编码免疫原性抗原的基因的完整序列将使用白色念珠菌序列数据库进行鉴定。在特定的目标2中，我们将使用实时定量逆转录聚合酶链式反应来证实这些基因在口腔或阴道粘膜中被诱导，但在体外的常规生长过程中不被诱导。我们还将使用针对纯化抗原的常规抗体来检测从HIV感染者身上回收的OPC和VVC样本，从而直接检测体内诱导的抗原。在这个项目中确定的粘膜特异性基因将在未来的项目中研究它们在念珠菌发病中的特定作用，最终目标是设计治疗和预防OPC和VVC的策略。

DESCRIPTION (provided by applicant): Oropharyngeal and vulvovaginal candidiasis (OPC and VVC), mucosal infections caused by Candida albicans, are the leading opportunistic infections among HIV-infected persons. In most humans, C. albicans is a harmless commensal of the gastrointestinal tract. The mechanisms by which the organism switches to an invasive pathogen are poorly understood. We hypothesize that pathogenesis at the oral and vaginal mucosa is facilitated by the expression of a subset of candidal genes that are specific to the mucosal surfaces. The major overall objective of our laboratory is to understand C. albicans gene expression during the pathogenesis of human infections. The goal of this R21 project is to identify C. albicans genes that are specifically expressed at the oral and/or vaginal mucosa, in order to identify genes that contribute to the pathogenesis of HIV associated candidiasis. To accomplish this, we will use saliva and vaginal fluid that are rich in locally produced anti-candidal antibodies to identify immunogenic C. albicans antigens. In preliminary studies, we created separate pools of saliva and vaginal fluid from HIV-infected persons with active OPC and VVC, respectively. The pooled samples were adsorbed against yeast and hyphae of C. albicans strains grown in vitro, as well as cell lysates. In Specific Aim 1, we will use the adsorbed samples, now concentrated in antibodies directed against antigens expressed uniquely within the human host, to screen a C. albicans genomic expression library in parallel. The complete sequences of the genes encoding immunogenic antigens will be identified using the C. albicans sequence databases. In Specific Aim 2, we will confirm that these genes are induced at the oral or vaginal mucosa, but not during routine growth in vitro, using quantitative real-time reverse transcription-polymerase chain reaction. We will also directly detect the in vivo induced antigens by using routine antibodies raised against the purified antigens to probe OPC and VVC samples recovered from HIV-infected persons. The mucosal-specific genes identified in this project will be studied in future projects for their specific roles during candidal pathogenesis, with the ultimate goal of designing strategies to treat and prevent OPC and VVC.