Characterization of Murine Bronchoalveolar Macrophage Respiratory Burst: Comparison of Soluble and Particulate Stimuli

Abstract

Stimulation of the respiratory burst of murine bronchoalveolar macrophages obtained by lung lavage was studied using four different stimuli and different assay conditions. One soluble stimulus, phorbol myristate acetate (PMA), two intracellular particles, zymosan and Blastomyces dermatitidis conida, and one extracellular particle, B. dermatitidis yeast, were incubated with either freshly obtained macrophages in suspension or 2- and 48-hour macrophage monolayers. Suspension cultures were incubated with stimuli for 90 minutes and monolayers for 10 minutes before O2- was assayed. PMA did not elicit O2- production in macrophage suspensions or 2-hour macrophage monolayers, but 48-hour macrophage monolayers exhibited a 13-fold increase above control values (P = .0001). On the other hand, zymosan elicited an increase in O2- production in both suspensions and monolayers, although monolayers incubated for 48 hours produced almost fourfold more O2- than the other systems (P = .025). Opsonization had no effect on the ability of zymosan to elicit respiratory burst. B. dermatitidis conidia resulted in a two- to threefold increase in O2- production in macrophage suspensions and a five- to eightfold increase in 48-hour monolayers, representing significantly less respiratory burst stimulation than with either zymosan or PMA. Similarly, B. dermatitidis yeasts demonstrated similar submaximal stimulation of O2-, 3-4 times that over control values, and again this was less than zymosan and PMA. We conclude that 1) freshly obtained murine bronchoalveolar macrophages do not respond to PMA with an increase in O2- production, but that responsiveness is evident after 48 hours of incubation in monolayers; 2) B. dermatitidis conidia and yeasts do not stimulate respiratory burst activity to the same degree as zymosan or PMA; and 3) opsonization of zymosan is not necessary for stimulation of the murine bronchoalveolar macrophage oxidative burst, confirming previous data that functional complement receptors are not present on these cells.

Production of H2O2 by Alveolar Macrophages in Experimental Allergic Alveolitis

“…The AM obtained at each BAL responded sharply to the stimulation with PMA. In this aspect, guinea pig AM are different than those of rabbit or mouse, which can be elicited by PMA only after a period of incubation with serum (12,31). Measurement of H2O2 production from guinea pig AM showed that these cells were very active in this respect (19).…”

Effect of Inhalation of Organic Dust-Derived Microbial Agents on the Pulmonary Phagocytic Oxidative Metabolism of Guinea Pigs

“…Following contact with and/or ingestion of inhaled dusts, pulmonary phagocytes often display an increase in oxygen consumption with concomitant increase in production of superoxide anion (O 2 -), hydrogen peroxide (H 2 O 2 ), and other reactive oxygen intermediates. These events are commonly referred to as the "respiratory burst" (Housset & Junod, 1983;Kaku et al, 1983;Pabst & Johnston, 1980;Sugar & Field, 1988;Ward et al, 1986). Little is known concerning the possible role of phagocyte-derived oxygen radicals in the pathogenesis of pulmonary diseases due to organic dusts.…”