Distinct macrophage phenotypes in allergic and nonallergic lung inflammation

Abstract

Chronic exposure to farm environments is a risk factor for nonallergic lung disease. In contrast to allergic asthma, in which type 2 helper T cell (Th2) activation is dominant, exposure to farm dust extracts (FDE) induces Th1/Th17 lung inflammation, associated with neutrophil infiltration. Macrophage influx is a common feature of both types of lung inflammation, allergic and nonallergic. However, macrophage functions and phenotypes may vary according to their polarized state, which is dependent on the cytokine environment. In this study, we aimed to characterize and quantify the lung macrophage populations in two established murine models of allergic and nonallergic lung inflammation by means of fluorescence-activated cell sorting and immunohistochemistry. We demonstrated that, whereas in allergic asthma M2-dominant macrophages predominated in the lungs, in nonallergic inflammation M1-dominant macrophages were more prevalent. This was confirmed in vitro using a macrophage cell line, where FDE exerted a direct effect on macrophages, inducing M1-dominant polarization. The polarization of macrophages diverged depending on the exposure and inflammatory status of the tissue. Interfering with this polarization could be a target for treatment of different types of lung inflammation.

Pulmonary delivery of cationic gold nanoparticles boost antigen-specific CD4 + T Cell Proliferation

“…Recent studies have emphasized the complex role of pulmonary macrophages in inflammatory processes due to their high level of plasticity and their ability to polarize into a plethora of different phenotypes depending on signals present in the microenvironment, 24,25 which may promote either pro-or anti-inflammatory responses. 26 One of the most important features of respiratory tract macrophages is their distinct phagocytic activity, contributing to tissue homeostasis by the clearance of invading pathogens, debris, as well as apoptotic cells, and preventing inflammatory responses from occurring in order to maintain vital alveolar gas exchange. 27,28 Moreover, uptake by macrophages is non-specific and NPs are likely to be degraded or inactivated.…”

Characteristics and Role of Macrophages in Pathogenesis of Acute and Chronic Lung Diseases

“…Так, было показано, что количество М1 значительно увеличено в легких мышей при не-аллергическом воспалении после воздействия экстрактом сельскохозяйственной пыли, что также было ассоциировано с увеличением по-пуляций Th1-и Th17-клеток, тогда как при ал-лергической БА наблюдалось увеличение М2-популяции [80]. Поляризованные М1 способны эффективно активировать Th1-клетки, секрети-руя CXCL10, IFNγ, IL-8, IL-23p40/p19, TNFα, IL-1β, RANTES, но не IL-12 (p40/p35) в ответ на заражение различными патогенами, включая микобактерии [31].…”

Interaction between allergic asthma and atherosclerosis

“…Thus, interfering with this polarization may potentially lead to the treatment of different types of lung inflammation. 63 …”