Hodzic Emir, Feng Sunlian, Barthold Stephen W
1 Center for Comparative Medicine, Schools of Veterinary Medicine and Medicine, University of California at Davis , Davis, California.
Vector Borne Zoonotic Dis. 2013 Oct;13(10):694-711. doi: 10.1089/vbz.2012.1189. Epub 2013 Aug 9.
Differential gene expression by Borrelia burgdorferi spirochetes during mammalian infection facilitates their dissemination as well as immune evasion. Modulation of gene transcription in response to host immunity has been documented with the outer surface protein C, but the influence of transcription of other genes is largely unknown. A low-density array (LDA) was developed to study transcriptional activity of 43 B. burgdorferi genes and 19 host genes that may be involved in various host-agent interactions. Gene transcription in heart, joint, and muscle tissue was compared in immunocompetent C3H and immunodeficient C3H-scid mice during early (3 weeks) and late (2 months) B. burgdorferi infection. Among all tissue types, levels of relative transcription of over 80% of B. burgdorferi genes tested were one- to nine-fold less in C3H mice compared to C3H-scid mice. At the later time point, all genes were transcribed in C3H-scid mice, whereas transcription of 16 genes out of 43 tested was not detected in analyzed tissues of C3H mice. Our data suggest that during infection of immunocompetent mice, a majority of B. burgdorferi genes tested are downregulated in response to acquired host immunity. LDA revealed variable patterns of host gene expression in different tissues and at different intervals in infected mice. Higher levels of relative expression for IL-10 during both early and late infection were detected in heart base, and it was unchanged in the tibiotarsal joint. Comparative analysis of B. burgdorferi and host genes transcriptional activity revealed that increased flaB mRNA during early infection was followed by increases of CCL7, CCL8, interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) in all assessed tissue types. LDA represents a valuable approach for sensitive and quantitative gene transcription profiling and for understanding Lyme borreliosis.
伯氏疏螺旋体在哺乳动物感染期间的差异基因表达有助于其传播以及免疫逃避。外表面蛋白C已被证明可响应宿主免疫调节基因转录，但其他基因转录的影响在很大程度上尚不清楚。开发了一种低密度阵列（LDA）来研究43个伯氏疏螺旋体基因和19个可能参与各种宿主-病原体相互作用的宿主基因的转录活性。在免疫健全的C3H小鼠和免疫缺陷的C3H-scid小鼠中，在伯氏疏螺旋体感染的早期（3周）和晚期（2个月）比较了心脏、关节和肌肉组织中的基因转录。在所有组织类型中，与C3H-scid小鼠相比，C3H小鼠中超过80%的测试伯氏疏螺旋体基因的相对转录水平低1至9倍。在较晚的时间点，所有基因在C3H-scid小鼠中都有转录，而在C3H小鼠的分析组织中未检测到43个测试基因中的16个基因的转录。我们的数据表明，在免疫健全小鼠感染期间，大多数测试的伯氏疏螺旋体基因会因获得性宿主免疫而被下调。LDA揭示了感染小鼠不同组织和不同时间间隔内宿主基因表达的可变模式。在心脏基部，在感染的早期和晚期均检测到较高水平的IL-10相对表达，而在胫跗关节中其表达没有变化。伯氏疏螺旋体和宿主基因转录活性的比较分析表明，在早期感染期间flaB mRNA增加后，所有评估组织类型中的CCL7、CCL8、白细胞介素-10（IL-10）和肿瘤坏死因子-α（TNF-α）都会增加。LDA是一种用于敏感和定量基因转录谱分析以及理解莱姆病的有价值的方法。
