Molestina Robert E, Klein Jon B, Miller Richard D, Pierce William H, Ramirez Julio A, Summersgill James T
Division of Infectious Diseases, Department of Medicine, University of Louisville School of Medicine, University of Louisville, Louisville, Kentucky 40292, USA.
Infect Immun. 2002 Jun;70(6):2976-81. doi: 10.1128/IAI.70.6.2976-2981.2002.
Recent data have shown that the respiratory pathogen Chlamydia pneumoniae expresses an altered gene transcription profile during gamma interferon (IFN-gamma)-induced persistent infection in vitro. In the present study, we examined, by proteomics, expression of C. pneumoniae proteins labeled intracellularly with [(35)S]methionine/cysteine under normal conditions or IFN-gamma-mediated persistence. The identity of differentially expressed proteins during persistent infection was determined by matching spots to those of proteins identified in C. pneumoniae elementary bodies by matrix-assisted laser desorption ionization mass spectrometry. Upon treatment with 50 U of IFN-gamma per ml, a marked upregulation of major outer membrane protein (MOMP), heat shock protein 60 (Hsp-60/GroEL), and proteins with functions in DNA replication (GyrA), transcription (RpoA, PnP), translation (Rrf), glycolysis (PgK, GlgP), and type III secretion (SctN) was observed at 24 h of infection. In contrast, no significant decreases in bacterial protein expression were found in C. pneumoniae-infected cells due to IFN-gamma treatment. Upregulation of C. pneumoniae proteins involved in diverse functions during persistent infection may allow the organism to resist the inhibitory effects of IFN-gamma while retaining basic functions. Future studies should examine the differential expression of chlamydial proteins during the developmental cycle under IFN-gamma pressure to obtain a finer representation of the gene products involved in establishing persistence.
最近的数据表明，呼吸道病原体肺炎衣原体在体外γ干扰素（IFN-γ）诱导的持续感染过程中表现出基因转录谱的改变。在本研究中，我们通过蛋白质组学方法，检测了在正常条件下或IFN-γ介导的持续感染情况下，用[³⁵S]甲硫氨酸/半胱氨酸细胞内标记的肺炎衣原体蛋白质的表达情况。通过将持续感染期间差异表达蛋白质的斑点与基质辅助激光解吸电离质谱法鉴定的肺炎衣原体原体中的蛋白质斑点进行匹配，确定了差异表达蛋白质的身份。在每毫升用50 U IFN-γ处理后，在感染24小时时观察到主要外膜蛋白（MOMP）、热休克蛋白60（Hsp-60/GroEL）以及在DNA复制（GyrA）、转录（RpoA、PnP）、翻译（Rrf）、糖酵解（PgK、GlgP）和III型分泌（SctN）中起作用的蛋白质显著上调。相比之下，由于IFN-γ处理，在肺炎衣原体感染的细胞中未发现细菌蛋白表达有显著下降。在持续感染期间，参与多种功能的肺炎衣原体蛋白质上调可能使该生物体在保留基本功能的同时抵抗IFN-γ的抑制作用。未来的研究应检查在IFN-γ压力下发育周期中衣原体蛋白质的差异表达，以更精细地呈现参与建立持续性的基因产物。
