In Vivo Physiological and Transcriptional Profiling Reveals Host Responses to Clostridium difficile Toxin A and Toxin B
In Vivo Physiological and Transcriptional Profiling Reveals Host Responses to Clostridium difficile Toxin A and Toxin B
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DOI：
10.1128/iai.00869-13
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发表时间：
2013-10-01
影响因子：
3.1
通讯作者：
Papin, Jason A.
中科院分区：
文献类型：
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作者：
D'Auria, Kevin M.;Kolling, Glynis L.;Papin, Jason A.
艰难梭菌的A毒素(TcdA)和B毒素(TcdB)可引起宿主的大体病理变化(如炎症、分泌物和腹泻)，但导致宿主反应的分子和细胞途径尚不清楚。为了弥补这一差距，我们评估了单剂量TcdA和/或TcdB注射到小鼠盲肠内的效果，并分析了几个终点，包括注射后2、6和16h的组织病理、中性粒细胞浸润、上皮层基因表达、趋化因子水平和血细胞计数。除了证实TcdA的大体病理效应外，我们还发现TcdA和TcdB都导致了中性粒细胞的浸润。生物信息学分析发现，与脂质、脂肪酸代谢和解毒相关的基因表达发生了变化；小的GTP酶活性；以及免疫功能和炎症。进一步分析发现，几种趋化因子(如CxCL1和CxCL2)瞬时表达。CXCL1和CXCL2的抗体中和不影响TcdA诱导的局部病理或中性粒细胞的浸润，但能减少外周血中中性粒细胞的数量。此外，低水平的血清CXCL1和CXCL2水平与更高的存活率相对应。尽管TcdA诱导了比TcdB更显著的转录变化，并且上调的趋化因子的表达是TcdA所特有的，但对TcdA和TcdB的总体转录反应是强烈相关的，主要支持在时间和效力上的差异，而不是细胞内宿主反应的类型。此外，转录数据揭示了新的毒素效应(例如，GTPase相关基因和代谢基因的变化)，这是对艰难梭菌毒素观察到的生理反应的潜在原因。
Toxin A (TcdA) and toxin B (TcdB) of Clostridium difficile cause gross pathological changes (e.g., inflammation, secretion, and diarrhea) in the infected host, yet the molecular and cellular pathways leading to observed host responses are poorly understood. To address this gap, we evaluated the effects of single doses of TcdA and/or TcdB injected into the ceca of mice, and several end-points were analyzed, including tissue pathology, neutrophil infiltration, epithelial-layer gene expression, chemokine levels, and blood cell counts, 2, 6, and 16 h after injection. In addition to confirming TcdA's gross pathological effects, we found that both TcdA and TcdB resulted in neutrophil infiltration. Bioinformatics analyses identified altered expression of genes associated with the metabolism of lipids, fatty acids, and detoxification; small GTPase activity; and immune function and inflammation. Further analysis revealed transient expression of several chemokines (e.g., Cxcl1 and Cxcl2). Antibody neutralization of CXCL1 and CXCL2 did not affect TcdA-induced local pathology or neutrophil infiltration, but it did decrease the peripheral blood neutrophil count. Additionally, low serum levels of CXCL1 and CXCL2 corresponded with greater survival. Although TcdA induced more pronounced transcriptional changes than TcdB and the upregulated chemokine expression was unique to TcdA, the overall transcriptional responses to TcdA and TcdB were strongly correlated, supporting differences primarily in timing and potency rather than differences in the type of intracellular host response. In addition, the transcriptional data revealed novel toxin effects (e.g., altered expression of GTPase-associated and metabolic genes) underlying observed physiological responses to C. difficile toxins.