Chlamydia pneumoniae dissemination and atherosclerosis

目前的研究表明，专性细胞内细菌肺炎衣原体（嗜衣原体）不仅与呼吸系统疾病，而且与动脉粥样硬化。为了了解健康人血液中肺炎衣原体的存活能力和生长潜力，我们首先采用实时荧光定量RT-PCR方法检测了70例健康人外周血单个核细胞（PBMCs）中肺炎衣原体的转录本。使用肺炎衣原体16 S rRNA的引物，通过实时RT-PCR评估健康人供体血液PBMC中肺炎衣原体转录物的存在。在70名供体中（18.5%）显示在培养的PBMC中存在细菌转录物。在与放线菌酮孵育的PBMNC培养物中，细菌检测的患病率和细菌数量显著增加。这些结果表明，健康人PBMC中可能存在活的肺炎衣原体。虽然有几项研究报告肺炎衣原体全身性疾病， ...更多信息 尽管通过基于DNA的定性方法在动物模型中从肺中排出，但缺乏允许活的肺炎衣原体从肺传播到血液的合适的动物模型阻碍了对活的肺炎衣原体如何到达血管并触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）小鼠对活肺炎衣原体从肺传播到血液的易感性，如通过实时RT-PCR检测的。多次鼻内接种后，在患有糖尿病的NOD小鼠（38.5%，n=13）以及ICR小鼠（40%，n=10）中检测到肺中的细菌，但在没有糖尿病的NOD小鼠[糖尿病前期NOD小鼠（n=8）和非糖尿病退休NOD小鼠（n=13）]中细菌的流行率非常低（5.2%，n=21）。仅在NOD糖尿病小鼠的PBMC中检测到细菌（53.8%）。在与氢化可的松孵育的PBMC培养物中，细菌检测的流行率似乎增加。来自所有NOD小鼠的培养的PBMC的肺炎衣原体的培养是不成功的。异硫氰酸荧光素标记的抗衣原体单克隆抗体的免疫染色结果也显示肺中存在细菌抗原，并且通过RT-PCR判断PBMCs为阳性。因此，糖尿病NOD小鼠对肺炎衣原体感染敏感，肺炎衣原体感染可能存在肺部细菌向血液的播散，本研究建立的动物模型可能有助于了解肺炎衣原体感染的播散。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