Chlamydia pneumoniae dissemination and atherosclerosis

目前的研究表明，专性细胞内细菌衣原体肺炎不仅与呼吸系统疾病有关，而且与动脉粥样硬化有关。在本研究中，为了了解健康人血液中检测到的肺炎原体的生存能力和生长潜力，我们首先尝试采用实时RT-PCR方法检测70名健康供者外周血单个核细胞（PBMCs）中的肺炎原体转录物。采用实时rt - pcr技术，利用肺炎原体16S rRNA引物对健康献血者血液中肺炎原体转录物的存在进行了评估。70个供体中（18.5%）在培养的pbmc中显示细菌转录物的存在。环己亚胺培养的PBMNC细菌检出率和细菌数量显著增加。这些结果表明，健康的人外周血单核细胞中可能存在活的肺炎原体。尽管有一些研究报道了肺炎原体的全体性感染，但通过基于dna的定性方法在动物模型中更多地从肺中清除，缺乏合适的动物模型来允许活的肺炎原体从肺传播到血液，这阻碍了对活的肺炎原体如何到达血管并引发动脉粥样硬化发展的理解。因此，我们接下来研究了非肥胖糖尿病（NOD）小鼠对活菌从肺到血液传播的易感性，通过实时RT-PCR检测。经多次鼻内接种后，在糖尿病NOD小鼠（38.5%,n=13）和ICR小鼠（40%,n=10）中检测到肺部细菌，但在非糖尿病NOD小鼠[糖尿病前期NOD小鼠（n=8）和非糖尿病NOD小鼠（n=13）]中细菌的患病率很低（5.2%,n=21）。该细菌仅在糖尿病NOD小鼠培养的pbmc中检测到（53.8%）。在氢化可的松培养的PBMC中，细菌检测的流行率似乎有所增加。从所有NOD小鼠培养的pbmc中培养肺炎原体均未成功。异硫氰酸荧光素偶联抗衣原体单克隆抗体免疫染色结果也显示肺中存在细菌抗原，RT-PCR判断PBMCs阳性。因此，糖尿病NOD小鼠对肺炎支原体感染敏感，其中活菌可能从肺向血液传播，本研究建立的动物模型可能有助于了解肺炎支原体感染的传播。少

Current studies have revealed that the obligate intracellular bacterium Chlamydia (Chlamydophila) pneumoniae is associated not only with respiratory diseases but also with atherosclerosis. In the present study, to understand the viability and growth potential of C.pneumoniae detected in blood of healthy persons, we first attempted to detect C.pneumoniae transcript in peripheral blood mononuclear cells (PBMCs) obtained from 70 healthy donors by real-time RT-PCR method. The presence of C.pneumoniae transcript in PBMCs from blood of healthy human donors was assessed by real-time RT-PCR-using primers for C.pneumoniae 16S rRNA. Out of 70 donors (18.5 %) showed the presence of bacterial transcript in cultured PBMCs. Prevalence of bacterial detection and bacterial numbers were significantly increased in PBMNC cultures incubated with cycloheximide. These results showed that viable C.pneumoniae might be present in healthy human PBMCs. Although several studies reported C.pneumoniae systemic diss … More emination from lung in animal model by DNA-based qualitative methods, the lack of a suitable animal model for permitting viable C.pneumonia dissemination from lung to blood has impeded the understanding of how viable C.pneumoniae can reach blood vessels and trigger the development of atherosclerosis. Therefore, we next studied the susceptibility of non-obese diabetic (NOD) mice to dissemination of viable C.pneumoniae from lung to blood, as detected by real-time RT-PCR. Following multiple intranasal inoculations, bacteria in lung were detected in NOD mice with diabetes (38.5%, n=13) as well as ICR mice (40%, n=10), but prevalence of bacteria in NOD mice without diabetes [Pre-diabetic NOD mice (n=8) and non-diabetic retired NOD mice (n=13)] was very low (5.2%, n=21). The bacteria were only detected in cultured PBMCs (53.8 %) of the NOD mice with diabetes. The prevalence of bacterial detection appeared to be increased in PBMC cultures incubated with hydrocortisone. Cultivation of C.pneumoniae from cultured PBMCs from all NOD mice was unsuccessful. Results of immunostaining with fluorescein isothiocyanate-conjugated anti-Chlamydia monoclonal antibody also showed the presence of bacterial antigens in the lungs and the PBMCs judged as positive by the RT-PCR. Thus, diabetic NOD mouse is sensitive to C.pneumoniae infection in which a possible dissemination of viable bacteria from lung to blood, and the animal model established in this study may be useful for understanding dissemination of C.pneumoniae infection. Less