Puerta-Arias Juan David, Pino-Tamayo Paula Andrea, Arango Julián Camilo, González Ángel
Medical and Experimental Mycology Unit, Corporación para Investigaciones Biológicas (CIB), Medellín, Colombia.
School of Microbiology, Universidad de Antioquia, Medellín, Colombia.
PLoS One. 2016 Sep 30;11(9):e0163985. doi: 10.1371/journal.pone.0163985. eCollection 2016.
Chronic stages of paracoccidioidomycosis (PCM) are characterized by granulomatous lesions which promote the development of pulmonary fibrosis leading to the loss of respiratory function in 50% of patients; in addition, it has been observed that neutrophils predominate during these chronic stages of P. brasiliensis infection. The goal of this study was to evaluate the role of the neutrophil during the chronic stages of experimental pulmonary PCM and during the fibrosis development and tissue repair using a monoclonal specific to this phagocytic cell. Male BALB/c mice were inoculated intranasally with 1.5x106 P. brasiliensis yeast cells. A monoclonal antibody specific to neutrophils was administered at 4 weeks post-inoculation followed by doses every 48h during two weeks. Mice were sacrificed at 8 and 12 weeks post-inoculation to assess cellularity, fungal load, cytokine/chemokine levels, histopathological analysis, collagen and expression of genes related to fibrosis development. Depletion of neutrophils was associated with a significant decrease in the number of eosinophils, dendritic cells, B cells, CD4-T cells, MDSCs and Treg cells, fungal load and levels of most of the pro-inflammatory cytokines/chemokines evaluated, including IL-17, TNF-α and TGF-β1. Recovery of lung architecture was also associated with reduced levels of collagen, high expression of TGF-β3, matrix metalloproteinase (MMP)-12 and -14, and decreased expression of tissue inhibitor metalloproteinase (TIMP)-2, and MMP-8. Depletion of neutrophils might attenuate lung fibrosis and inflammation through down-regulating TGF-β1, TNF-α, IL-17, MMP-8 and TIMP-2. These results suggest that neutrophil could be considered as a therapeutic target in pulmonary fibrosis induced by P. brasiliensis.
副球孢子菌病（PCM）的慢性阶段以肉芽肿性病变为特征，这些病变会促进肺纤维化的发展，导致50%的患者呼吸功能丧失；此外，据观察，在巴西副球孢子菌感染的这些慢性阶段，中性粒细胞占主导。本研究的目的是使用针对这种吞噬细胞的单克隆抗体，评估中性粒细胞在实验性肺部PCM慢性阶段以及纤维化发展和组织修复过程中的作用。雄性BALB/c小鼠经鼻接种1.5×10⁶个巴西副球孢子菌酵母细胞。在接种后4周给予针对中性粒细胞的单克隆抗体，随后在两周内每48小时给药一次。在接种后8周和12周处死小鼠，以评估细胞数量、真菌负荷、细胞因子/趋化因子水平、组织病理学分析、胶原蛋白以及与纤维化发展相关基因的表达。中性粒细胞的耗竭与嗜酸性粒细胞、树突状细胞、B细胞、CD4⁺T细胞、髓系来源的抑制细胞（MDSCs）和调节性T细胞（Treg细胞）数量的显著减少、真菌负荷以及所评估的大多数促炎细胞因子/趋化因子水平的降低有关，包括白细胞介素-17（IL-17）、肿瘤坏死因子-α（TNF-α）和转化生长因子-β1（TGF-β1）。肺结构的恢复还与胶原蛋白水平降低、TGF-β3、基质金属蛋白酶（MMP）-12和-14的高表达以及金属蛋白酶组织抑制剂（TIMP）-2和MMP-8的表达降低有关。中性粒细胞的耗竭可能通过下调TGF-β1、TNF-α、IL-17、MMP-8和TIMP-2来减轻肺纤维化和炎症。这些结果表明，中性粒细胞可被视为巴西副球孢子菌诱导的肺纤维化的治疗靶点。
