BACKGROUND: In vitro, endotoxin on coarse fraction particulate matter (PM2.5-10) accounts for the majority of the ability of PM2.5-10 to induce cytokine responses from alveolar macrophages. OBJECTIVE: We examined in vivo whether inhaled PM2.5-10 from local ambient air induce inflammatory and immune responses in the airways of healthy human beings and whether biologic material on PM2.5-10 accounts for these effects. METHODS: On 3 separate visits, 9 healthy subjects inhaled nebulized saline (0.9%, control), PM2.5-10 collected from local ambient air that was heated to inactivate biological material (PM2.5-10-), or nonheated PM (PM2.5-10+). PM2.5-10 deposition (approximately 0.65 mg/subject) targeted the bronchial airways (confirmed by using radiolabeled aerosol), and induced sputum was obtained 2 to 3 hours postinhalation for analysis of cellular and biochemical markers of inflammation and innate immune function. RESULTS: Inhaled PM2.5-10+ induced elevated inflammation (% PMNs, macrophage mRNA TNF-alpha), increased eotaxin, upregulated immune surface phenotypes on macrophages (mCD14, CD11b, HLA-DR), and increased phagocytosis (monocytes) versus saline (P < .05). Biological inactivation of PM2.5-10 (PM2.5-10-) had no effect on neutrophilia but significantly (P < .05) attenuated mRNA TNF-alpha, eotaxin levels, cell surface marker responses, and phagocytosis. CONCLUSION: Biological components of PM2.5-10 are not necessary to induce neutrophil responses but are essential in mediating macrophage responses. The ability of PM2.5-10 to activate monocytic cells and potentially skew the airways toward an allergic phenotype by enhancing eotaxin levels may enhance responses to allergens or bacteria in individuals with allergy. CLINICAL IMPLICATIONS: PM2.5-10 might enhance the response of individuals with allergy to airborne bacteria.
BACKGROUND: In vitro, endotoxin on coarse fraction particulate matter (PM2.5-10) accounts for the majority of the ability of PM2.5-10 to induce cytokine responses from alveolar macrophages. OBJECTIVE: We examined in vivo whether inhaled PM2.5-10 from local ambient air induce inflammatory and immune responses in the airways of healthy human beings and whether biologic material on PM2.5-10 accounts for these effects. METHODS: On 3 separate visits, 9 healthy subjects inhaled nebulized saline (0.9%, control), PM2.5-10 collected from local ambient air that was heated to inactivate biological material (PM2.5-10-), or nonheated PM (PM2.5-10+). PM2.5-10 deposition (approximately 0.65 mg/subject) targeted the bronchial airways (confirmed by using radiolabeled aerosol), and induced sputum was obtained 2 to 3 hours postinhalation for analysis of cellular and biochemical markers of inflammation and innate immune function. RESULTS: Inhaled PM2.5-10+ induced elevated inflammation (% PMNs, macrophage mRNA TNF-alpha), increased eotaxin, upregulated immune surface phenotypes on macrophages (mCD14, CD11b, HLA-DR), and increased phagocytosis (monocytes) versus saline (P < .05). Biological inactivation of PM2.5-10 (PM2.5-10-) had no effect on neutrophilia but significantly (P < .05) attenuated mRNA TNF-alpha, eotaxin levels, cell surface marker responses, and phagocytosis. CONCLUSION: Biological components of PM2.5-10 are not necessary to induce neutrophil responses but are essential in mediating macrophage responses. The ability of PM2.5-10 to activate monocytic cells and potentially skew the airways toward an allergic phenotype by enhancing eotaxin levels may enhance responses to allergens or bacteria in individuals with allergy. CLINICAL IMPLICATIONS: PM2.5-10 might enhance the response of individuals with allergy to airborne bacteria.
Authors: Jill A Poole; Todd A Wyatt; Tammy Kielian; Peter Oldenburg; Angela M Gleason; Ashley Bauer; Gregory Golden; William W West; Joseph H Sisson; Debra J Romberger Journal: Am J Respir Cell Mol Biol Date: 2011-01-28 Impact factor: 6.914
Authors: Matthew J Strickland; Lyndsey A Darrow; Mitchel Klein; W Dana Flanders; Jeremy A Sarnat; Lance A Waller; Stefanie E Sarnat; James A Mulholland; Paige E Tolbert Journal: Am J Respir Crit Care Med Date: 2010-04-08 Impact factor: 21.405
Authors: Michelle L Hernandez; Margaret Herbst; John C Lay; Neil E Alexis; Willie June Brickey; Jenny P Y Ting; Haibo Zhou; David B Peden Journal: J Allergy Clin Immunol Date: 2012-07-04 Impact factor: 10.793
Authors: Neelakshi Hudda; John L Durant; Alexandra Nemeth; Phyllis Mann; Jocelyn Petitto; Douglas Brugge; Benjamin C Nephew Journal: Inhal Toxicol Date: 2019-11-25 Impact factor: 2.724