Hydrogen peroxide enhances phagocytosis of Pseudomonas aeruginosa in hyperoxia.
Mechanical ventilation with hyperoxia is a necessary treatment for patients with respiratory distress. However, patients on mechanical ventilation have increased susceptibility to infection. Studies including ours have shown that reactive oxygen species (ROS), generated by exposure to prolonged hyperoxia, can cause a decrease in the phagocytic activity of alveolar macrophages. Hydrogen peroxide (H₂O₂) is a form of ROS generated under hyperoxic conditions. In this study, we examined whether treatment with H₂O₂ directly affects macrophage phagocytic ability in RAW 264.7 cells that were exposed to either 21% O₂ (room air) or 95% O₂ (hyperoxia). Moderate concentrations (ranging from 10 to 250 μM) of H₂O₂ significantly enhanced macrophage phagocytic activity and restored hyperoxia-suppressed phagocytosis through attenuation of hyperoxia-induced disorganization of actin cytoskeleton and actin oxidation. These results indicate that H₂O₂ at low-moderate concentrations can be beneficial to host immune responses by improving macrophage phagocytic activity.
Department of Pharmaceutical Sciences, St. John's University College of Pharmacy, Queens, NY 11439, USA.
Binh D
BD
Phan
Maria
M
Entezari
Richard A
RA
Lockshin
Diana C
DC
Bartelt
Lin L
LL
Mantell
D000199:Actins / Q000378:metabolism; D000332:Aerobiosis; D000818:Animals; D002460:Cell Line; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000382:microbiology / Q000502:physiology; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology*; D010587:Phagocytosis / Q000187:drug effects*; D011550:Pseudomonas aeruginosa / Q000254:growth & development
D000199:Actins; D006861:Hydrogen Peroxide; D010100:Oxygen