Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, Member of the German Center for Lung Research, Neuherberg, Germany;
Institute of Experimental Genetics, Helmholtz Zentrum Muenchen, Neuherberg, Germany;
Am J Physiol Lung Cell Mol Physiol. 2014 Nov 1;307(9):L692-706. doi: 10.1152/ajplung.00092.2014. Epub 2014 Aug 15.
Chronic obstructive pulmonary disease (COPD) is characterized by a progressive decline in lung function, caused by exposure to exogenous particles, mainly cigarette smoke (CS). COPD is initiated and perpetuated by an abnormal CS-induced inflammatory response of the lungs, involving both innate and adaptive immunity. Specifically, B cells organized in iBALT structures and macrophages accumulate in the lungs and contribute to CS-induced emphysema, but the mechanisms thereof remain unclear. Here, we demonstrate that B cell-deficient mice are significantly protected against CS-induced emphysema. Chronic CS exposure led to an increased size and number of iBALT structures, and increased lung compliance and mean linear chord length in wild-type (WT) but not in B cell-deficient mice. The increased accumulation of lung resident macrophages around iBALT and in emphysematous alveolar areas in CS-exposed WT mice coincided with upregulated MMP12 expression. In vitro coculture experiments using B cells and macrophages demonstrated that B cell-derived IL-10 drives macrophage activation and MMP12 upregulation, which could be inhibited by an anti-IL-10 antibody. In summary, B cell function in iBALT formation seems necessary for macrophage activation and tissue destruction in CS-induced emphysema and possibly provides a new target for therapeutic intervention in COPD.
慢性阻塞性肺疾病(COPD)的特征是肺功能进行性下降,这是由暴露于外源性颗粒引起的,主要是香烟烟雾(CS)。COPD 是由 CS 引起的肺部异常炎症反应引发和持续的,涉及固有免疫和适应性免疫。具体来说,组织在 iBALT 结构中的 B 细胞和巨噬细胞在肺部积聚并有助于 CS 引起的肺气肿,但其中的机制尚不清楚。在这里,我们证明 B 细胞缺陷小鼠对 CS 引起的肺气肿有明显的保护作用。慢性 CS 暴露导致 iBALT 结构的大小和数量增加,以及肺顺应性和平均线性弦长增加,但在 B 细胞缺陷小鼠中没有增加。在 CS 暴露的 WT 小鼠中,iBALT 周围和肺气肿肺泡区域中肺驻留巨噬细胞的积累增加,与 MMP12 表达上调一致。使用 B 细胞和巨噬细胞进行的体外共培养实验表明,B 细胞衍生的 IL-10 驱动巨噬细胞活化和 MMP12 上调,这可以被抗 IL-10 抗体抑制。总之,iBALT 形成中的 B 细胞功能似乎对于 CS 诱导的肺气肿中的巨噬细胞活化和组织破坏是必要的,并且可能为 COPD 的治疗干预提供新的靶标。