The host immune responses to Staphylococcus epidermidis, a frequent cause of nosocomial infections, are not well understood. We have established a bath immersion model of this infection in zebrafish (Danio rerio) larvae. Macrophages play a primary role in the host immune response and are involved in clearance of infection in the larvae. S. epidermidis infection results in upregulation of tlr-2. There is marked inflammation characterized by heightened NF-κB signaling and elevation of several proinflammatory cytokines. There is rapid upregulation of il-1b and tnf-a transcripts, whereas an increase in il-6 levels is relatively more delayed. The IL-6 signaling pathway is further amplified by elevation of IL-6 signal transducer (il-6st) levels, which negatively correlates with miRNA dre-miR-142a-5p. Enhanced IL-6 signaling is protective to the host in this model as inhibition of the signaling pathway resulted in increased mortality upon S. epidermidis infection. Our study describes the host immune responses to S. epidermidis infection, establishes the importance of IL-6 signaling, and identifies a potential role of miR-142-5p–il-6st interaction in this infection model.

宿主对表皮葡萄球菌（医院感染的常见原因）的免疫反应尚不清楚。我们已经在斑马鱼 ( Danio rerio ) 幼虫中建立了这种感染的浴浸模型。巨噬细胞在宿主免疫反应中起主要作用，并参与清除幼虫感染。表皮葡萄球菌感染导致tlr-2上调。存在以 NF-κB 信号增强和几种促炎细胞因子升高为特征的明显炎症。il-1b和tnf-a转录物快速上调，而il-6水平相对滞后。IL-6 信号转导通路通过 IL-6 信号转导 ( il-6st ) 水平的升高进一步放大，这与 miRNA dre-miR-142a-5p 呈负相关。在该模型中，增强的 IL-6 信号传导对宿主具有保护作用，因为信号传导途径的抑制导致表皮葡萄球菌感染后死亡率增加。我们的研究描述了宿主对表皮葡萄球菌感染的免疫反应，确定了 IL-6 信号传导的重要性，并确定了 miR-142-5p –il-6st相互作用在该感染模型中的潜在作用。