HOST-C ALBICANS INTERACTION AT MUCOSAL SURFACES IN AIDS

艾滋病中宿主-C 白色念珠菌在粘膜表面的相互作用

• 批准号: 6100305
• 负责人: MICHAEL F. COLE
• 金额: $ 23.75万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-15 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6100305
• 关键词: AIDS; Candida albicans; antibody formation; candidiasis; chemical fingerprinting; endopeptidases; enzyme linked immunosorbent assay; genetic strain; host organism interaction; human immunodeficiency virus; human subject; immunoglobulin A; longitudinal human study; mucosal immunity; opportunistic infections; virulence; western blottings

Candida albicans is a member of the normal flora of mucosal surfaces that usually exists in a commensal relationship with the host unless the flora is perturbed or the immune system compromised when this fungus an become opportunistically pathogenic. Immunosuppression resulting from infection with the human immunodeficiency virus (HIV) leads to oral and vaginal candidiasis in over 90% of patients with AIDS. Mucosal defense is mediated principally by secretory immunoglobulin A (SIgA) antibodies which inhibit adherence of C. albicans. HIV infection results in the progressive depletion of CD4+ T lymphocytes and disruption of the follicular dendritic cell network in germinal centers. 60% of all lymphocytes are found in the mucosal-associated lymphoid tissues that are the inductive sites for SigA antibody responses and memory. The objective of this application is to define the salivary and vaginal secretory immune responses to C. albicans in men and women with AIDS. Sequential samples of saliva and vaginal secretions and isolates of C. albicans will be obtained from HIV+ men and women and healthy controls during a four year longitudinal study. Data will be analyzed to test the following hypotheses: (1) The susceptibility of AIDS patients to oral and vaginal candidiasis results from impaired SigA antibody responses due to disregulation of the immune system; (2) Strains of C. albicans colonizing AIDS patients are more virulent, genetically less diverse than those in healthy subjects, show tropism for the mouth or vagina and persist in these habitats. The Specific Aims are: Aim 1A. Determine the levels of total SigA, SigA1 and SigA2 subclasses in saliva and vaginal secretions of AIDS patients. Total SigA,SigA1 and SigA2 will be quantitated using an enzyme-linked immunosorbent assay (ELISA) specific for exocrine IgA to test the hypothesis that progressive AIDS results in reduced concentrations of SigA and its subclasses in saliva and vaginal secretions. Aim 1B. Analyze the quantity and specificity of total SigA, SigA1 and SigA2 antibodies reactive with C. albicans in saliva and vaginal secretions. The specificity and quantity of antibodies will be analyzed by Western blotting and by ELISA to test the hypotheses that the quantity and specificity of antibodies changes throughout the progression of AIDS. Aim 1C. Analyze the avidity of total SigA, SigA1 and SigA2 antibodies reactive with C. albicans in saliva and vaginal secretions. Chaotrope dissociation ELKISA and immunoblots will be used to test the hypothesis that progressive AIDS results in the production of low avidity antibodies that do not exhibit affinity maturation and are ineffective in immune elimination of this fungus. Aim 2. Compare the SigA proteinase activity of C. albicans isolates from the mouth and vagina and t he levels of proteinase in saliva and vaginal secretions. SigA-degrading enzymes will be detected by a radial diffusion assay and by ELISA using proteinase-specific antibody to test the hypothesis that these enzymes contribute to the virulence of this fungus by destroying SigA antibodies. Aim 3: Compare the genetic diversity of C. albicans isolates obtained from the mouth and vagina. DNA fingerprinting will be used to test the hypotheses that in AIDS patients there is; (a) limited genetic heterogeneity within the strains of this species isolated from the mouth and vagina; (b) different genotypes of Candida in the mouth compared with the vagina and (c) genotypes of this fungus are stable in these habitats over time.

白色念珠菌是粘膜表面正常植物群的成员， 通常与寄主植物有亲缘关系，除非植物群 是干扰或免疫系统受到损害时，这种真菌一成为 机会性致病 感染导致的免疫抑制 与人类免疫缺陷病毒（HIV）导致口腔和阴道 90%以上的艾滋病患者感染念珠菌病。 粘液防御是通过 主要是通过分泌型免疫球蛋白A（SIgA）抗体， C.坚持。白色念珠菌 艾滋病毒感染导致进行性 CD 4 + T淋巴细胞耗竭和滤泡树突状细胞破坏 养老中心的细胞网络。 60%的淋巴细胞存在于 作为SigA诱导位点的粘膜相关淋巴组织 抗体反应和记忆 本申请的目的是 定义唾液和阴道分泌免疫反应的C。白色 在艾滋病患者身上。 唾液和阴道的连续样本 分泌物和分离物。白色念珠菌将从HIV+男性中获得， 女性和健康对照组在为期四年的纵向研究。 数据 将进行分析，以检验以下假设：（1） 艾滋病患者对口腔和阴道念珠菌感染的易感性 由于免疫调节失调， 系统;（2）C.艾滋病患者体内的白色念珠菌 毒性，遗传多样性低于健康受试者，显示 趋向于口腔或阴道，并在这些栖息地持续存在。 的 具体目标是：目标1A。 测定总SigA、SigA 1和 艾滋病患者唾液和阴道分泌物中的SigA 2亚类 总 SigA、SigA 1和SigA 2将使用酶联免疫分析仪定量。 免疫吸附测定（ELISA）特异性外分泌伊加，以测试 进行性艾滋病导致SigA浓度降低的假说 以及唾液和阴道分泌物中的亚类。 目标1B。 分析 总SigA、SigA 1和SigA 2抗体反应性的量和特异性 梭唾液和阴道分泌物中的白色念珠菌。 的特异性和 将通过Western印迹和ELISA分析抗体的量， 检验抗体数量和特异性变化的假设 在艾滋病的发展过程中。 目标1C。 分析总的亲和力 与C.唾液中的白色念珠菌， 阴道分泌物 离液剂解离ELKISA和免疫印迹将在 用于检验进行性艾滋病导致产生 低亲合力抗体不表现出亲和力成熟， 对这种真菌的免疫消除无效。 目标2. 比较SigA C.蛋白酶活性白色念珠菌从口腔和阴道分离， 唾液和阴道分泌物中的蛋白酶水平。 SigA降解 酶将通过径向扩散测定和ELISA检测， 蛋白酶特异性抗体来测试这些酶 通过破坏SigA抗体来增强这种真菌的毒力。 目的3：比较不同种间的遗传多样性.白色念珠菌分离株， 口腔和阴道 DNA指纹将用于测试 假设艾滋病患者有;（a）有限的遗传 从口腔分离的该物种菌株内的异质性 （B）口腔中念珠菌的不同基因型， 阴道和（c）这种真菌的基因型在这些生境中是稳定的 随着时间