Cellular immune reactions in the lung

Abstract

Summary The lung constantly interacts with the environment through thousands of liters of air that are inhaled daily. This continually transports toxic chemicals and particles or pathogenic microorganisms deep into the respiratory system, posing a challenge to physicochemical barriers and the local immune system. Thus, complex structures and mechanisms have evolved to recognize and fend off environmental dangers while at the same time allowing efficient gas exchange. Here we review our current knowledge regarding cellular mechanisms of the immune system in context with the highly specialized anatomical features of the airways and especially the alveolar compartment. The focus is on fungal and viral infections, merging anatomical aspects well known to pulmonologists with fundamental immunological concepts. We discuss the specialized morphological constraints of immune cells compressed under a continuous layer of the surfactant lining within alveoli as well as the importance of functional polarization of respiratory tract epithelia. Furthermore, we summarize the different types of innate and adaptive immune cells and their relative contribution to lung homeostasis with respect to localization. Finally, we provide a list of currently unresolved questions with high relevance for the field that might serve as food for thought regarding future research directions.

Viral–bacterial interactions in the respiratory tract

“…As professional antigen presenting cells, dendrtic cells (DCs) are at the interface between innate and adaptive immunity in the lung, where different DC subsets have distinct functions (Guilliams et al, 2013;Hasenberg et al, 2013).…”

Progress in using the drugs based on hydrobionts in treatment of respiratory viral infections and their complications

“…Разница в данных иммунологических ответах определяется классом запускаемых цитокинов. В целом функция Т-клеток имеет определяющее значение в разре-шении респираторной вирусной инфекции, так как Т-клеточный ответ может привести к значительному повреждению тканей [19]. Так, у мышей с дефици-том Т-клеток, зараженных вирусом гриппа, на фоне повышенного вирусного титра и отсроченной ле-тальности проявления симптомов легочной патоло-гии были ниже, чем в контроле [19].…”

Complementation of a manganese-dependent superoxide dismutase-deficient yeast strain with Pneumocystis carinii sod2 gene

“…They are generated as byproducts of aerobic metabolism (Venditti et al 2013) or by stimulated host immune effectors cells, such as neutrophils, monocytes and macrophages (Nathan & Cunningham-Bussel 2013;Hasenberg et al 2013). Complex networks of ROSdetoxifying systems have been developed by pathogens to cope with this detrimental oxidative stress.…”

“…The Pneumocystis organisms inhabit the alveolar microenvironment where the phagocytes of the innate immune system protect the airways by releasing ROS (Hasenberg et al 2013). Pneumocystis ROS-detoxifying pathways probably have an important role in the fungal development inside the lung.…”