Phagocytosis of heat-killed Staphylococcus aureus by eosinophils: comparison with neutrophils.
Eosinophils are characterized by several functional properties, such as chemotaxis, adhesion, superoxide anion production, and degranulation. In this article, we have studied the role of bacterial ingestion by eosinophils in comparison with that by neutrophils. Eosinophils and neutrophils were purified by using the Percoll gradient method followed by selection with CD16-coated immunomagnetic beads and centrifugation through a Ficoll-Hypaque gradient combined with dextran sedimentation, respectively. Both cells were preincubated with anti-FcgammaRIIa mAb (CD32 mAb), anti-FcgammaRIIIb mAb (CD16 mAb), anti-CR3 (CD11b mAb), or anti-CR1 (CD35 mAb) before being examined for phagocytosis of opsonized heat-killed Staphylococcus aureus (S. aureus). Phagocytosis and production of hydrogen peroxide were simultaneously measured by flow cytometry using S. aureus labeled with propidium iodide and stained with 2',7'-dichlorofluorescein diacetate. Eosinophils showed significantly lower activity than neutrophils in both phagocytosis and hydrogen peroxide production. Phagocytosis by both cells was decreased by heat-inactivated serum. Phagocytosis by neutrophils was significantly inhibited by CD16 mAb and CD32 mAb, whereas that by eosinophils was only inhibited by CD35 mAb. Whereas the mechanism of phagocytosis by neutrophils was mediated by CD16 and CD32, that of eosinophils was modulated by complement receptor 1 (CD35).
Hatano
Yasuko
Y
Department of Pediatrics, Kansai Medical University, Osaka, Japan. hatanoy@takii.kmu.ac.jp
Taniuchi
Shoichiro
S
Masuda
Midori
M
Tsuji
Shoji
S
Ito
Taichi
T
Hasui
Masafumi
M
Kobayashi
Yohnosuke
Y
Kaneko
Kazunari
K
D000328:Adult; D039481:CD11b Antigen / Q000032:analysis; D004804:Eosinophils / Q000276:immunology*; D058851:GPI-Linked Proteins; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology*; D010587:Phagocytosis; D017463:Receptors, Complement 3b / Q000032:analysis; D017452:Receptors, IgG / Q000032:analysis; D013211:Staphylococcus aureus / Q000276:immunology*
D039481:CD11b Antigen; C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; C509295:ITGAM protein, human; D017463:Receptors, Complement 3b; D017452:Receptors, IgG; D006861:Hydrogen Peroxide