Pathogenesis of Haemophilus ducreyi Infections

杜克雷嗜血杆菌感染的发病机制

• 批准号: 6887307
• 负责人: Stanley M. Spinola
• 金额: $ 33.53万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6887307
• 关键词: HIV infections; Haemophilus ducreyi; adhesin; bacterial antigens; bacterial genetics; biopsy; clinical research; communicable disease transmission; confocal scanning microscopy; cytokine; disease /disorder model; genetic strain; helper T lymphocyte; human tissue; immunocytochemistry; immunoelectron microscopy; membrane proteins; microorganism immunology; model design /development; monoclonal antibody; mutant; pathologic process; pilus; sexually transmitted diseases; virulence

EXCEED THE SPACEPROVIDED. Haemophilus ducreyi causes chancroid, a genital ulcer disease that facilitates HIV transmission. Lacking specimens from naturally infected patients, we developed an experimental model of infection of the skin in human subjects, which resembles natural disease in both its clinical course and histopathology. Throughout the course of experimental infection, the H. ducreyi colocalizes with PMNs and macrophages in the epidermis and upper dermis, and with collagen and fibrin in the dermis. Despite its association with phagocytic cells, H. ducreyi remains predominantly extracellular during experimental infection. The relevance of these findings to natural infection is unknown. We have tested 10 isogenic mutant/parent pairs in the model. Many of these mutants were evaluated because in vitro studies suggested that the gene of interest encoded a virulence determinant. However, only 3 of the mutants were impaired in their ability to progress to pustule formation. Thus, genes that have functions in vitro frequently do not contribute to pustule formation in vivo. Identification of bacterial genes that are exclusively or differentially induced in vivo has led to many fundamental observations about host-pathogen interactions. We recently amplified //. ducreyi transcripts from biopsies of experimental lesions. With the completion of the H. ducreyi genome sequence, we wish to address hypotheses about expression of bacterial genes during human infection, where the bacteria are exposed to a relevant tissue (human skin) and a relevant host response. Our first hypothesis is that H. ducreyi continues to colocalize with PMNs, macrophages and collagen and fibrin during the ulcerative stage of disease and remains primarily extracellular throughout infection. Our second hypothesis is that specific virulence determinants are differentially upregulated by H. ducreyi during infection, and that isogenic mutants in these upregulated genes will be attenuated in the model. To test these hypotheses our aims include: localization of the bacteria in naturally occurring lesions; capture of bacterial transcripts differentially upregulated in vivo; construction of isogenic mutants in selected differentially upregulated genes; evaluation of the mutants in the model. PERFORMANCE SITE ========================================Section End===========================================

超过太空保护。 嗜血杆菌Ducreyi会导致Chancroid，这是一种促进HIV传播的生殖器溃疡疾病。缺乏自然感染患者的标本，我们开发了人类受试者皮肤感染的实验模型，在其临床病程和组织病理学中都类似于天然疾病。在整个实验感染过程中，杜克里氏菌与表皮和上真皮的PMN和巨噬细胞共定位，以及真皮中的胶原蛋白和纤维蛋白。尽管它与吞噬细胞相关，但在实验感染期间，杜卡里氏菌仍主要是细胞外的。这些发现与自然感染的相关性尚不清楚。 我们已经在模型中测试了10个等源性突变体/父对。评估了许多这些突变体，因为体外研究表明，感兴趣的基因编码了毒力决定因素。但是，只有3个突变体的发展能力损害了脓疱形成的能力。因此，具有体外功能的基因经常不会导致体内脓疱形成。 鉴定仅在体内诱导或差异诱导的细菌基因已导致许多有关宿主 - 病原体相互作用的基本观察。我们最近放大//。来自实验病变活检的Ducreyi转录本。随着H. ducreyi基因组序列的完成，我们希望解决有关人类感染过程中细菌基因表达的假设，其中细菌暴露于相关组织（人皮）和相关的宿主反应。 我们的第一个假设是，在疾病的溃疡性阶段，杜克里氏菌继续与PMN，巨噬细胞以及胶原蛋白和纤维蛋白共定位，并且在整个感染过程中仍主要保持细胞外。我们的第二个假设是，特定的毒力决定因素在感染过程中被H. ducreyi差异上调，并且这些上调的基因中的同基因突变体将在模型中减弱。为了检验这些假设，我们的目标包括：细菌在天然发生的病变中的定位；捕获细菌转录物在体内差异上调；在选定的差异上调基因中构造等源性突变体；评估模型中的突变体。 表演站点=============================================================================================