EUBACTERIA IN PATHOGENESIS OF SYSTEMIC LUPUS ERYTHEMATOSUS

真细菌在系统性红斑狼疮发病机制中的作用

• 批准号: 6332129
• 负责人: SHIRLEY A KOVACS
• 金额: $ 3.22万
• 依托单位: CALIFORNIA STATE UNIVERSITY FRESNO
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6332129
• 关键词: RNA splicing; RNase protection assay; antigen antibody reaction; autoantibody; bacterial antigens; disease /disorder etiology; enzyme linked immunosorbent assay; gene complementation; immunofluorescence technique; laboratory mouse; northern blottings; nucleic acid hybridization; nucleic acid sequence; pathologic process; photosynthetic bacteria; polymerase chain reaction; proliferating cell nuclear antigen; ribonucleoproteins; systemic lupus erythematosus; western blottings

Systemic Lupus Erythematosus (SLE) is an autoimmune arthritic disease of unknown etiology but behaves as an antigen-driven response to the nuclear component, U1 small nuclear ribonucleoprotein particle (U1snRNP). U1nsRNPs are highly conserved among eukaryotes but not thought to exist in prokaryotic organisms. However our work suggests that ribonucleoprotein particles displaying high homology to U1snRNPs do exist among eubacteria. As bacterial snRNPs could provide an antigenic stimulus which might lead to autoimmunity, a small group of SLE-susceptible MRL-lpr/lpr mice were injected with extracts from one of the "U1snRNP"-positive bacteria. The mice injected with bacterial extracts displayed early expression of certain clinical and immunological symptoms of SLE, commencing about two weeks after inoculation (mice were one month old at inoculation). This proposal intends to examine the details of this immune response through variations in immunization dose and time relevant to "natural" disease course and to include more thorough clinical, histopathological and immunological assessments of the outcomes. Clinical criteria will principally include assessments of arthritis, lymph node hyperplasia and alopecia; histopathological criteria will principally monitor tissue abnormalities in joints, kidneys and lymph nodes; and immunologic criteria will use ELISA reactivity to human nuclear extract and to bacterial extract for titers and isotypic profiles, direct immunofluorescence to detect glomerulonephritis, indirect immunofluorescence to detect reactivity to specific nuclear antigens, and western blotting to determine reactivity to U1snRNP-specific proteins MRL-lpr/lpr mice immunized with physiological saline and random genetic mice (Swiss-Webster) injected either the bacterial extract or saline will serve as experimental controls. Other candidate "U1snRNP"- containing bacterial organisms will be identified and/or evaluated using computer-based genomics, the polymerase chain reaction (PCR), northern hybridization and RNase protection assays, and mRNA splicing- complementation assays. Finally, the ability of these candidate prokaryotic cell extracts to stimulate SLE will be assessed by immunization of MRL-lpr/lpr mice and assessment of clinical, histopathological and immunological symptoms. The outcome of these experiments should provide a cleared indication of whether: inoculation with pro-karyotic cells; and these latter pro-karyotic cells can also stimulate SLE symptoms in MRL-lpr/lpr model mice. The possibility that bacteria are etiological agents of SLE unveils a wealth of antibiotic therapeutic opportunities for treatment of SLE or other autoimmune, rheumatological disorders.

系统性红斑狼疮（SLE）是一种病因不明的自身免疫性关节炎疾病，但其表现为对核成分U1小核核糖核蛋白颗粒（U1snRNP）的抗原驱动反应。U1nsRNPs在真核生物中高度保守，但在原核生物中不存在。然而，我们的工作表明，在真细菌中确实存在与U1snRNPs具有高度同源性的核糖核蛋白颗粒。由于细菌snrnp可以提供抗原刺激，可能导致自身免疫，因此，我们向一小群sle敏感的MRL-lpr/lpr小鼠注射了一种“U1snRNP”阳性细菌的提取物。注射细菌提取物的小鼠在接种后约两周（小鼠接种时为1个月大）就表现出SLE的某些临床和免疫症状的早期表达。本提案旨在通过与“自然”疾病病程相关的免疫剂量和时间的变化来研究这种免疫反应的细节，并对结果进行更彻底的临床、组织病理学和免疫学评估。临床标准主要包括关节炎、淋巴结增生和脱发的评估；组织病理学标准将主要监测关节、肾脏和淋巴结的组织异常；免疫标准将使用ELISA对人核提取物和细菌提取物的反应性来检测滴度和同型谱，直接免疫荧光检测肾小球肾炎，间接免疫荧光检测对特定核抗原的反应性，用生理盐水免疫的MRL-lpr/lpr小鼠和注射细菌提取物或生理盐水的随机遗传小鼠（Swiss-Webster）作为实验对照。其他候选的含有“U1snRNP”的细菌有机体将通过基于计算机的基因组学、聚合酶链反应（PCR）、northern杂交和RNase保护试验以及mRNA剪接-互补试验进行鉴定和/或评估。最后，这些候选原核细胞提取物刺激SLE的能力将通过免疫MRL-lpr/lpr小鼠和评估临床、组织病理学和免疫学症状来评估。这些实验的结果应该提供一个明确的指示是否：接种原核细胞；这些前核细胞也能刺激MRL-lpr/lpr模型小鼠的SLE症状。细菌可能是SLE的病因，这为治疗SLE或其他自身免疫性疾病、风湿病提供了大量的抗生素治疗机会。