Innate Immunity and the Pathogenicity of Inhaled Microbial Particles

Abstract

Non-infectious inhaled microbial particles can cause illness by triggering an inappropriate immunological response. From the pathogenic point of view these illnesses can be seen to be related to on one hand autoimmune diseases and on the other infectious diseases.In this review three such illnesses are discussed in some detail. Hypersensitivity pneumonitis (HP) is the best known of these illnesses and it has also been widely studied in animal models and clinically. In contrast to HP Pulmonary mycotoxicosis (PM) is not considered to involve immunological memory, it is an acute self-limiting condition is caused by an immediate "toxic" effect. Damp building related illness (DBRI) is a controversial and from a diagnostic point poorly defined entity that is however causing, or attributed to cause, much more morbidity than the two other diseases.In the recent decade there has been a shift in the focus of immunology from the lymphocyte centered, adaptive immunity towards innate immunity. The archetypal cell in innate immunity is the macrophage although many other cell types participate. Innate immunity relies on a limited number of germline coded receptors for the recognition of pathogens and signs of cellular damage. The focus on innate immunity has opened new paths for the understanding of many chronic inflammatory diseases. The purpose of this review is to discuss the impact of some recent studies, that include aspects concerning innate immunity, on our understanding of the pathogenesis of inflammatory diseases associated with exposure to inhaled microbial matter.

Moisture damage in home associates with systemic inflammation in children

“…Our study suggests that moisture damage with or without mold in the home may increase the levels of CRP and be associated with systemic inflammatory mechanisms in children. These results are in agreement with the view that the pathogenesis of damp buildingrelated respiratory symptoms is the induction of inflammation and involves proinflammatory cytokines (WHO Regional Office for Europe, 2009;Wolff, 2011;Leino et al, 2003;Pylkkanen et al, 2004). Interestingly, increased level of IL-1a/b induces production of GM-CSF, G-CSF, IL-6, IL-8, TNF-a, IL-1Ra, soluble TNF-a receptor, ACTH, cortisol and nitric oxide, and induction of general symptoms (Dinarello, 2011) which are often observed in people living in moisture dam- Table 3 Association of moisture damage/mold in different locations of the house at the age of 6 years and cytokines (non-stimulated and PI-stimulation) at the age of 6 years aged houses.…”

Application of Airborne Microorganism Indexes in Offices, Gyms, and Libraries

“…The monitoring of bioaerosols represents an important tool both for assessing the risk in the working environment [10] and for the evaluation of the environmental impact of certain activities that take place outdoors, such as biopurification or waste disposal [11]. Several investigations have been directed to study the disease called Sick Building Syndrome (SBS), which is characterized by varied and non-specific symptoms observed in workers employed in confined environments [12][13][14]. The World Health Organization has defined SBS as "an increase in frequency in the occupants of non-industrial buildings, of not specific acute symptoms (irritation of eyes, nose, throat, headache, fatigue, nausea) that improve when building is left" [15].…”

IL-1β and Inflammasome Activity Link Inflammation to Abnormal Fetal Airway Development

“…Inhaled microbes and particles contact multiple cell types in the airways (8, 9). However, alveolar macrophages are the primary initial sites of particle and microbial phagocytosis and subsequent inflammatory activation (10, 11).…”