State Key Laboratory of Agrobiotechnology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, People's Republic of China.
Can J Microbiol. 2011 Sep;57(9):722-9. doi: 10.1139/w11-066. Epub 2011 Aug 19.
Staphylococcus sciuri causes multiple infections in humans. Recently, a strain of S. sciuri (HBXX06) carrying exfoliative toxin C (ExhC) was reported to cause fatal exudative epidermal skin pathology in piglets and might be considered as a potential zoonotic agent. However, little is known about the pathogenicity of this bacterium. In this study, we examined the activity of recombinant ExhC-his (rExhC) protein using newborn mice as the model and investigated the effect of rExhC on macrophage functions. Interestingly, we found that both rExhC and S. sciuri ExhC existed as dimers and that rExhC inhibited the phagocytosis of RAW264.7 cell lines but enhanced the production of proinflammatory mediators, such as interleukin-6, interleukin-12, tumor necrosis factor α, and nitric oxide, by murine peritoneal macrophages and RAW264.7 cells. These results suggest that ExhC may play an important role in innate immune response against S. sciuri infection.
松鼠葡萄球菌可引起人类多种感染。最近，有报道称一株携带表皮剥脱毒素 C（ExhC）的松鼠葡萄球菌（HBXX06）可导致仔猪致命性渗出性表皮皮肤病理学变化，可能被视为一种潜在的人畜共患病原体。然而，对于这种细菌的致病性知之甚少。在本研究中，我们使用新生小鼠作为模型，检测了重组 ExhC-his（rExhC）蛋白的活性，并研究了 rExhC 对巨噬细胞功能的影响。有趣的是，我们发现 rExhC 和 S. sciuri ExhC 均以二聚体形式存在，rExhC 抑制 RAW264.7 细胞系的吞噬作用，但增强了鼠腹腔巨噬细胞和 RAW264.7 细胞产生促炎介质，如白细胞介素-6、白细胞介素-12、肿瘤坏死因子-α和一氧化氮。这些结果表明 ExhC 可能在针对松鼠葡萄球菌感染的固有免疫反应中发挥重要作用。
