Macrophage damage in relation to the pathogenesis of lung diseases.

Abstract

Pulmonary macrophages are important since their migratory patterns and behavior are often pivotal events in the pathogenesis of pulmonary disease. Alveolar macrophages act to decrease the probability of particle penetration through epithelial barriers, and their phagocytic and lytic potentials provide most of the known bactericadal properties of the lung. Macrophages are also involved in immune responses and in defense against neoplasms. Increased inert or infectious particles stimulate the recruitment of additional macrophages. Most free cells containing particles eventually reach the airways and are quickly carried to the pharynx and swallowed. In addition, evidence has now accumulated that macrophages play a part in the pathogenesis of pulmonary diseases. For example, the ingestion of some particles by macrophages causes a release of lysosomal enzymes into the macrophage cytoplasm. These enzymes may kill the macrophage, and dead or dying macrophages release a substance with attracts fibroblasts that elicit fibrogenic responses. Other toxic particles, such as cigarette smoke, my lead to a release of proteases and other toxic enzymes. All particles are capable of competitive inhibition of phagocytosis in macrophages and many may be cytotoxic and further depress phagocytosis. In addition, connective tissue macrophages may contribute to lung disease by concentrating and storing potent carcinogens or other toxic particles close to a reactive bronchial epithelium for long periods. Thus, even through macrophages serve as a first line of defense for the alveolar surface, they may also be capable of injuring the host while exercising their defensive role.

Effects of zinc oxide nanoparticles on Kupffer cell phagosomal motility, bacterial clearance, and liver function

“…26 Modifications in relaxation rates have been reported as a result of toxic exposures; generally, lower relaxation rates indicate decreases in cytoskeleton function and/or toxicity. This technique has been used as an indicator of altered macrophage function after exposure to various toxins, such as cigarette smoke, 27 malaria infection, 16 and particles. 28 In this study, we assessed the effects of IV-injected ZnO ENPs on Kupffer cell phagosomal motility using in vivo magnetometry and on clearance of bacteria from the blood and subsequent killing using bacteriological techniques.…”

Role of T-lymphocytes and pro-inflammatory mediators in the pathogenesis of chronic obstructive pulmonary disease

“…The presence of intrapulmonary infl ammation in COPD has been appreciated for many years, and accumulations and functions of activated macrophages and polymorphonuclear leukocytes (components of the innate immune system) have long been believed to be important in disease development (Brain 1980;Schleime 2005;Tetley 2005;Quint and Wedzicha 2007). More recent reports have suggested that the adaptive immune response also contributes to the pathophysiology of COPD.…”

Comparativein vitrocytotoxicity of volcanic ashes from Mount St. Helens, El Chichon, and Galunggung

“…Increasing evidence suggests that alveolar macrophages participate in the pathogenesis of lung disease (Brain, 1980). The release of macrophage cytosolic and lysosomal enzymes when exposed to volcanic ashes and silica suggests a loss of cellular integrity.…”