Innate Immunity of the Lung: From Basic Mechanisms to Translational Medicine

Abstract

The respiratory tract is faced daily with 10,000 L of inhaled air. While the majority of air contains harmless environmental components, the pulmonary immune system also has to cope with harmful microbial or sterile threats and react rapidly to protect the host at this intimate barrier zone. The airways are endowed with a broad armamentarium of cellular and humoral host defense mechanisms, most of which belong to the innate arm of the immune system. The complex interplay between resident and infiltrating immune cells and secreted innate immune proteins shapes the outcome of host-pathogen, host-allergen, and host-particle interactions within the mucosal airway compartment. Here, we summarize and discuss recent findings on pulmonary innate immunity and highlight key pathways relevant for biomarker and therapeutic targeting strategies for acute and chronic diseases of the respiratory tract.

A Quantitative Proteome Map of the Human Body

“…Further analysis revealed a common group of 78 proteins involved in immunity were enriched in both lung and spleen. Recent studies have shown that lung hosts many immune cells and is a large reservoir of neutrophils, likely accounting for the similarity (18).…”

Animal Models Reflecting Chronic Obstructive Pulmonary Disease and Related Respiratory Disorders: Translating Pre-Clinical Data into Clinical Relevance

“…2). Air pollutants such as cigarette smoke (CS) inhaled through the nose and mouth induce airway epithelium and macrophages to release chemotactic factors, including interleukin (IL)-4, 5, 6, 8, and 13, interferon-γ-induced protein 10 (IP10), monokine induced by interferon-γ, and leukotriene B 4 , which attract and activate key inflammatory cells lining the airway mucosa [96,97]. Sustained activation results in airway accumulation of neutrophils, CD8 T cells, and/or CD4 helper T cells [98,99].…”

Once upon a Time

“…Lungs therefore need to be differently protected than other organs. This said, studies focusing on basic pulmonary immune responses will provide important information about the molecular mechanisms which could be used for therapeutic applications [5]. Concerning COVID-19 infections this is of particular importance as patients with underlying diseases such as chronic obstructive pulmonary disease (COPD) are at higher risk to suffer more severe complications.…”