中性粒细胞通过成熟局部 APC 扩增自身免疫性中枢神经系统浸润。
Neutrophils amplify autoimmune central nervous system infiltrates by maturing local APCs.
机构信息
Zentrum für Molekulare Neurobiologie, Universitätsklinikum Hamburg-Eppendorf, D-20251 Hamburg, Germany.
出版信息
J Immunol. 2013 Nov 1;191(9):4531-9. doi: 10.4049/jimmunol.1202613. Epub 2013 Sep 23.
Multiple sclerosis is considered to be initiated by a deregulated, myelin-specific T cell response. However, the formation of inflammatory CNS lesions and the contribution of different leukocyte subsets in setting up these lesions are still incompletely understood. In this study, we show that, in the mouse model of multiple sclerosis, experimental autoimmune encephalomyelitis, neutrophil granulocytes are important contributors in preparing CNS inflammation. Preclinical single-dose Ab-mediated depletion of neutrophils delayed the onset and continuous depletion attenuated the development of experimental autoimmune encephalomyelitis, whereas the generation of a myelin-specific T cell response remained unaffected. Neutrophil-related enzymes such as myeloperoxidase and neutrophil elastase did not contribute in mounting CNS inflammation, as analyzed by using respective knockout mice and inhibitors. CNS-infiltrating neutrophils secreted proinflammatory molecules and matured bone marrow-derived dendritic cells in vitro, which in turn enhanced their ability to restimulate myelin-specific T cells. This was mirrored in vivo, in which depletion of neutrophils specifically impaired maturation of microglia and macrophages into professional APCs, resulting in a diminished amplification of early CNS inflammation. Therefore, inside the CNS neutrophils provide local cofactors that are required for the maturation of myeloid cells into professional APCs representing an essential step for the local restimulation of myelin-specific T cells and the development of autoimmune disease.
多发性硬化被认为是由失调的、针对髓鞘的 T 细胞反应引发的。然而,炎症性中枢神经系统病变的形成以及不同白细胞亚群在建立这些病变中的作用仍不完全清楚。在这项研究中,我们表明,在多发性硬化症的小鼠模型——实验性自身免疫性脑脊髓炎中,中性粒细胞是引发中枢神经系统炎症的重要因素。临床前单次 Ab 介导的中性粒细胞耗竭延迟了疾病的发作,持续耗竭则减弱了实验性自身免疫性脑脊髓炎的发展,而髓鞘特异性 T 细胞反应的产生则不受影响。通过使用相应的基因敲除小鼠和抑制剂,我们发现中性粒细胞相关酶,如髓过氧化物酶和中性粒细胞弹性蛋白酶,并未参与引发中枢神经系统炎症。中枢神经系统浸润的中性粒细胞在体外分泌促炎分子,并使骨髓来源的树突状细胞成熟,进而增强了它们再次刺激髓鞘特异性 T 细胞的能力。这在体内得到了印证,其中中性粒细胞的耗竭特异性地损害了小胶质细胞和巨噬细胞向专业 APC 的成熟,导致早期中枢神经系统炎症的放大作用减弱。因此,中枢神经系统内的中性粒细胞提供了局部共刺激因子,这些因子对于髓样细胞向专业 APC 的成熟是必需的,这是局部再次刺激髓鞘特异性 T 细胞和自身免疫病发展的关键步骤。