寡核苷酸芯片研究结核分枝杆菌临床株和无毒株诱导的巨噬细胞U937凋亡相关基因的差异表达

结核病仍然是人类健康的主要威胁,结核分枝杆菌诱导的巨噬细胞凋亡是宿主防御反应之一,研究凋亡相关基因的差异表达有助于认识结核分枝杆菌致病机理和发现新的药物靶标。利用包括19200个基因或基因片段的DNA芯片研究巨噬细胞株U937对临床和实验室菌株感染的差异表达,Northem blotting和RT—PCR验证了芯片研究结果。Mtb H37Rv感染下调bcl—2,vitaminD受体、干扰素调控因子3、细胞色素氧化酶C表达,幅度分别为2-,3-,3-,2．5-倍,临床菌株感染上调SOD2、SOD3、丝氨酸蛋白酶、toll—like受体2、signal transducer and activator(STAT1)、hypoxia—inducible factor22等表达,幅度分别为2．9-,2．5-,2．5-,22-,2．4-,5．9-倍。结果提示,临床菌株感染更多促进凋亡,限制宿主的杀灭机理。该研究为进一步研究导致这些差异表达的结核分枝杆菌成分提供了基础。     

结核分枝杆菌入侵诱导的人巨噬细胞全局性基因表达变化

利用含有12800个基因全长或部分序列的基因芯片研究结核分枝杆菌无毒株入侵导致的人巨噬细胞U937全基因组在转录水平的表达谱变化. 结果表明其中473个基因(3.7%)差异表达, 表达上调的基因25个(5.3%), 上调超过3倍的包括丝氨酸/苏氨酸蛋白质激酶, 可溶性结合半乳糖苷的凝集素, 蛋白质酪氨酸磷酸酶delta, DDR受体酪氨酸激酶等的编码基因, 其余基因(94.7%)表达下调. 表达下调的基因中, 表达仅为原来1/3以下的25个, 其中syndecan 结合蛋白的表达下调12.5倍. 芯片研究结果与结核分枝杆菌一般抑制宿主细胞免疫应答的趋势相符. 这473个基因中的376个基因在GenBank中有记录, 另外97个是新基因. 生物信息学分析提示差异表达基因编码产物与细胞内信号传导、细胞因子反应、细胞骨架重建、细胞凋亡、铁代谢、电子传递、线粒体功能和离子通道等有关. 这些差异表达基因中, 有17个是文献报道过的, 而且都印证了本文的结果. RT-PCR和Northern杂交实验确证了表达谱芯片研究结果. 通过DNA芯片研究全局表达谱变化, 揭示了细菌入侵早期导致的巨噬细胞表达变化, 为深入研究结核分枝杆菌-宿主相互作用提供了基础数据和探索方向.     

结核分枝杆菌感染诱导的人巨噬细胞细胞因子及其调控基因的差异表达谱

研究人巨噬细胞细胞因子在抗结核分枝杆菌感染免疫中的作用。利用表达谱芯片技术研究细菌感染后,宿主巨噬细胞基因表达情况,在全局表达谱分析基础上,重点分析细胞因子及相关基因的表达,并比较无毒株和临床分离有毒株在诱导细胞因子及其调控基因表达方面的差异。结果显示细菌感染影响较多细胞因子及其调控基因的表达,如IFN、TNF、TGF、IL系列及其受体、NFkappa B和TLR受体等;首次报道IL19参与了抗结核分枝杆菌感染免疫。被临床株感染影响的细胞因子较无毒株广泛和丰富。细胞因子及相关基因参与了宿主细胞对感染细菌的免疫应答,有关细胞因子及相关基因在抗结核免疫中的作用有待进一步研究。     

Exploring<Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> infection-induced alterations in gene expression in macrophage by microarray hybridization

Tuberculosis remains a serious threat to public health. Its causative agentMycobacterium tuberculosis is an intracellular pathogen which survives and replicates within cells of the host immune system, primarily macrophages. Knowledge of the bacteria-macrophage interaction can help to develop novel measures to combat the disease. The global gene expression of macrophage following invasion by and growth ofM. tuberculosis was studied by cDNA microarray. Of the 12800 human genes analyzed, totally 473 (3.7%) macrophage genes were differentially expressed after being infected byM. tuberculosis, among which, only 25 (5.2%, corresponding to less than 0.2% of the 12800 genes) genes were up-regulated, while others (94.8%) were down-regulated against the control. Of the 473 genes, 376 genes are registered in the GenBank, and 97 are novel genes. Expression of 5 up-regulated genes has been induced by more than 3-fold. 25 genes were down-regulated by more than 3-fold. Syndecan binding protein has been down-regu- lated up to 12.5-fold. The data gave an insight into the early gene expression in macrophage ensuingM. tuberculosis infection and a basis for further study.     

Exploring Mycobacterium tuberculosis infection-induced alterations in gene expression in macrophage by microarray hybridization

Tuberculosis remains a major global threat to human health, with 8 million cases of clinical tuberculosis and 3 million deaths annually[1] (www.stoptb.org/tuberculosis/#facts.html). Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis. The emergence of multi-drug resistant strains of Mtb and co-infection with the human immunodeficiency virus (HIV) have further emphasized the need for effective prevention and treatment of tuberculosis. Mtb is a facultative intracellular pat…