Flow Cytometric Analysis of Macrophage Oxidative Metabolism Using DCFH

Macrophages throughout the body function to phagocytose pathogens, tissue debris, or foreign particulates. For example, lung macrophages have frequent contact with inhaled pathogens or inert particles and have developed interesting and diverse responses to these challenges. One response of particular interest is the respiratory burst (RB), which involves converting oxygen into reactive oxygen intermediate species (ROI). Depending on the amount and site of production, these oxidants can contribute to intracellular signaling, participate in killing of ingested microorganisms, or cause injury to the cell itself or adjacent tissues (1 ,2 ). Indiscriminate production of oxidants by alveolar macrophages (AMs) interacting with otherwise innocuous environmental particles could have deleterious consequences for the lung. Flow cytometric analysis of particle uptake and intracellular RB has enhanced our understanding of AM-particle interactions and determinants that lead to a RB or down-regulation of potentially harmful AM responses (3 –6 ).