IMMUNOREACTIVE MACROMOLECULES OF COCCIDIOIDES CELL TYPES

球孢子细胞类型的免疫反应性大分子

• 批准号: 3128558
• 负责人: GARRY Thomas COLE
• 金额: $ 21.72万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-09-01 至 1992-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3128558
• 关键词: Coccidioides immitis; T lymphocyte; antifungal antibody; biological polymorphism; cell type; cell wall; chemical structure function; chimeric proteins; coccidioidomycosis; enzyme mechanism; fungal antigens; gene expression; genetic library; host organism interaction; human tissue; immunodiffusion; immunoelectron microscopy; immunoelectrophoresis; immunofluorescence technique; laboratory mouse; laboratory rabbit; leukocyte activation /transformation; microorganism immunology; monoclonal antibody; nucleic acid probes; nucleic acid sequence; recombinant DNA; tissue /cell culture; western blottings

Coccidioides immitis is a fungal respiratory pathogen of humans and causative agent of valley fever (coccidioidomycosis). Exposure to the airborne, infectious cells (arthroconidia) can lead to a range of clinical disease from a benign, self-limited infectious cells (arthroconidia) can lead to a range of clinical disease from a benign, self-limited infection to a severe, progressive and often fatal mycosis involving pulmonary and extrapulmonary tissues. Immunologically compromising illnesses, although present in some patients, are not prerequisite to infection by C. immitis. There exists a consistent and predictable immunological pattern in patients at various stages of coccidioidomycosis, which may be related to initial exposure to the arthroconidia, followed by repeated exposure to soluble antigenic fractions of primarily wall origin during the parasitic cycle (i.e., spherule-endospore phase). Our hypothesis is that arthroconidia, spherules, and endospores of C. immitis elicit different host responses because of qualitative and/or quantitative differences in the antigenic composition of their cell wall to which the host is originally exposed. It has been possible to isolate soluble, antigenic complexes from the cell envelopes off arthroconidia and spherules grown in vitro, characterize their immunoreactivity in humoral and cellular immunoassays, and obtain purified components using various separation techniques. In the proposed investigations we will characterize these purified components on the basis of their chemical composition, antigenic identity in standardized immunoelectrophoresis and immunodiffusion tests, and relative immunoreactivity in assays which measure patient antibody adsorption and T-cell response to the homogeneous fractions. We will also examine the biological function of these purified components, with focus on their possible enzymatic activity and impact on fungal morphogenesis and host invasion. Our recent development of a cDNA expression library and the availability of a genomic library for C. immitis permits application of recombinant DNA technology in our further characterization of these purified, wall-associated fractions. Initially, we will screen the libraries using selected immunoprobes and oligonucleotide probes corresponding to those selected fractions with established significance in host antibody response, tissue invasion, or C. immitis morphogenesis, and clone the genes which regulate production off the homologous fusion peptides. Ultimately, we will determine expression of these genes during arthroconidium-spherule-endospore development in vitro. We believe that this comprehensive approach to the study of C. immitis antigens will lead to a better understanding of the pattern of immunological response by the host and factors which contribute to pathogenicity, as well as identify potential diagnostic DNA probes and molecular targets for development of novel antifungal compounds.

粗球孢子菌 (Coccidioides immitis) 是一种人类呼吸道病原体， 谷热（球孢子菌病）的病原体。暴露于 空气传播的传染性细胞（节孢子虫）可导致一系列 来自良性、自限性感染细胞的临床疾病 （节孢子虫）可导致一系列临床疾病，包括良性、 自限性感染发展为严重、进行性且常常致命的真菌病 累及肺组织和肺外组织。免疫学上 尽管某些患者存在损害疾病，但并不 C. immitis 感染的先决条件。存在一个一致且 不同阶段患者的可预测免疫模式 球孢子菌病，可能与最初接触 节孢子，然后反复暴露于可溶性抗原 寄生周期期间主要由壁起源的部分（即 小球-内生孢子相）。我们的假设是节分孢子， C. immitis 的小球和内生孢子引起不同的宿主反应 由于抗原的定性和/或定量差异 宿主最初接触的细胞壁的组成。 已经可以从其中分离出可溶性抗原复合物 体外生长的节孢子和小球的细胞包膜， 表征其在体液和细胞免疫测定中的免疫反应性， 并使用各种分离技术获得纯化的组分。在 我们将在拟议的研究中表征这些纯化的 基于其化学成分、抗原特性的成分 在标准化免疫电泳和免疫扩散测试中，以及 测量患者抗体的测定中的相对免疫反应性 吸附和 T 细胞对均质组分的反应。我们也会 检查这些纯化成分的生物学功能，重点是 关于它们可能的酶活性及其对真菌形态发生的影响 和宿主入侵。我们最近开发的 cDNA 表达文库 以及 C. immitis 基因组文库的可用性允许 重组DNA技术在我们进一步表征中的应用 这些纯化的、与壁相关的级分。最初，我们会筛选 使用选定的免疫探针和寡核苷酸探针的文库 对应于那些选定的具有确定意义的分数 在宿主抗体反应、组织侵袭或粗念珠菌形态发生中， 并克隆调节同源融合产生的基因 肽。最终，我们将确定这些基因在 节分孢子-小球-内生孢子体外发育。我们相信 这种研究 C. immitis 抗原的综合方法将导致 以便更好地了解免疫反应的模式 宿主和导致致病性的因素，以及识别 潜在的诊断DNA探针和分子靶标的开发 新型抗真菌化合物。