Calreticulin Blockade Attenuates Murine Acute Lung Injury by Inducing Polarization of M2 Subtype Macrophages
Calreticulin Blockade Attenuates Murine Acute Lung Injury by Inducing Polarization of M2 Subtype Macrophages
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DOI：
10.3389/fimmu.2020.00011
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发表时间：
2020-01-30
影响因子：
7.3
通讯作者：
Zhu, Lei
中科院分区：
文献类型：
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作者：
Jiang, Zhilong;Chen, Zhihong;Zhu, Lei
钙网蛋白(CALR)通过促进树突状细胞成熟和肿瘤抗原提呈而发挥抗肿瘤作用。然而，CALR是否影响巨噬细胞并调节急性呼吸窘迫综合征/急性肺损伤(ARDS/ALI)的进展仍不清楚。在本研究中，我们发现在脂多糖诱导的ALI小鼠中CALR蛋白高表达，并且CALR的表达水平与ALI的严重程度呈正相关。商品化抗CALR抗体(ACALR)能中和重组CALR(RCALR)，抑制rCALR诱导的巨噬细胞表达肿瘤坏死因子-α和IL-6。腹腔注射阻断CALR活性(Ip)应用aCALR可显著抑制ALI，并伴有肺组织和支气管肺泡灌洗液(BAL)中细胞总数、中性粒细胞和T细胞的减少。ACALR组小鼠CXCL15、IL-6、IL-1β、TNF-α和CALR的表达显著降低，并伴随着Siglec F+CD206+M2亚型巨噬细胞的极化。预先去除循环单核细胞并不能取消aCALR介导的对ALI的抑制。进一步的骨髓巨噬细胞分析表明，aCALR抑制CD80、IL-6、IL-1β、IL-18、NLRP3和p-p38MAPK的表达，但增强CD206和IL-10的表达。此外，我们观察到在aCALR处理的BMDM中STAT6的表达和磷酸化程度更高。缺乏STAT6导致在aCALR处理的BMDM中，CALR、TNF-α和IL-6的表达水平与未处理的细胞相比略有升高。因此，CALR是评价ALI的一种新的生物标志物。用aCALR阻断CALR活性可有效抑制不依赖循环单核细胞的ALI。Siglec F+CD206+M2亚型巨噬细胞和p38MAPK/STAT6信号通路在aCALR的免疫调节中起重要作用。阻断CALR活性是治疗ARDS/ALI的一种有前景的治疗方法。
Calreticulin (CALR) has anti-tumor effects by increasing dendritic cell maturation and tumor antigen presentation. However, whether CALR affects macrophages and modulates progression of acute respiratory distress syndrome/acute lung injury (ARDS/ALI) remains unknown. In this study, we discovered that CALR protein was highly expressed in the mice with LPS-induced ALI and CALR expression level was positively correlated to the severity of ALI. Commercial anti-CALR antibody (aCALR) can neutralize recombinant CALR (rCALR) and suppress the expression of TNF-alpha and IL-6 in the rCALR-treated macrophages. Blocking CALR activity by intraperitoneal (i.p.) administration of aCALR significantly suppressed ALI, accompanied with lower total cell counts, neutrophil and T cell infiltration in bronchoalveolar lavage (BAL) and lung tissues. The expression of CXCL15, IL-6, IL-1beta, TNF-alpha, and CALR were significantly reduced, in association with more polarization of Siglec F+CD206+M2 subtype macrophages in the aCALR-treated mice. Pre-depletion of circulating monocytes did not abolish the aCALR-mediated suppression of ALI. Further analysis in bone marrow-derived macrophages (BMDMs) showed that aCALR suppressed the expression of CD80, IL-6, IL-1beta, IL-18, NLRP3, and p-p38 MAPK; but enhanced the expression of CD206 and IL-10. In addition, we observed more expression and phosphorylation of STAT6 in the aCALR-treated BMDM. Lack of STAT6 resulted in comparable and slightly higher expression of CALR, TNF-alpha and IL-6 in the aCALR-treated STAT6-/- BMDMs than the untreated cells. Therefore, we conclude that CALR is a novel biomarker in the evaluation of ALI. Blocking CALR activity by aCALR effectively suppressed ALI independent of circulating monocytes. Siglec F+CD206+M2 subtype macrophages and p38 MAPK/STAT6 signaling pathway played important role in the immune regulation of aCALR. Blocking CALR activity is a promising therapeutic approach in the treatment of ARDS/ALI.