The pathogenesis of pulmonary fibrosis, including idiopathic pulmonary fibrosis (IPF) and other forms of interstitial lung disease, involves a complex interplay of various factors including host genetics, environmental pollutants, infection, aberrant repair and dysregulated immune responses. Highly variable clinical outcomes of some ILDs, in particular IPF, have made it difficult to identify the precise mechanisms involved in disease pathogenesis and thus the development of a specific cure or treatment to halt and reverse the decline in patient health. With the advent of in-depth molecular diagnostics, it is becoming evident that the pathogenesis of IPF is unlikely to be the same for all patients and therefore will likely require different treatment approaches. Chronic inflammation is a cardinal feature of IPF and is driven by both innate and adaptive immune responses. Inflammatory cells and activated fibroblasts secrete various pro-inflammatory cytokines and chemokines that perpetuate the inflammatory response and contribute to the recruitment and activation of more immune cells and fibroblasts. The balance between pro-inflammatory and regulatory immune cell subsets, as well as the interactions between immune cell types and resident cells within the lung microenvironment, ultimately determines the extent of fibrosis and the potential for resolution. This review examines the role of the innate and adaptive immune responses in pulmonary fibrosis, with an emphasis on IPF. The role of different immune cell types is discussed as well as novel anti-inflammatory and immunotherapy approaches currently in clinical trial or in preclinical development.

肺纤维化的发病机制，包括特发性肺纤维化（IPF）和其他形式的间质性肺疾病，涉及多种因素的复杂相互作用，包括宿主遗传学、环境污染物、感染、异常修复和免疫反应失调。一些 ILD（特别是 IPF）的临床结果差异很大，因此很难确定疾病发病机制中涉及的精确机制，从而难以开发出特定的治愈方法或治疗方法来阻止和扭转患者健康状况的恶化。随着深入分子诊断的出现，越来越明显的是，IPF 的发病机制不太可能对所有患者都相同，因此可能需要不同的治疗方法。慢性炎症是 IPF 的主要特征，由先天性和适应性免疫反应驱动。炎症细胞和活化的成纤维细胞分泌各种促炎细胞因子和趋化因子，使炎症反应持续存在，并有助于招募和激活更多的免疫细胞和成纤维细胞。促炎性和调节性免疫细胞亚群之间的平衡，以及免疫细胞类型和肺微环境中常驻细胞之间的相互作用，最终决定纤维化的程度和消退的潜力。本综述探讨了先天性和适应性免疫反应在肺纤维化中的作用，重点是 IPF。讨论了不同免疫细胞类型的作用以及目前正在临床试验或临床前开发中的新型抗炎和免疫治疗方法。