Superoxide production at phagosomal cup/phagosome through beta I protein kinase C during Fc gamma R-mediated phagocytosis in microglia.
Protein kinase C (PKC) plays a prominent role in immune signaling. To elucidate the signal transduction in a respiratory burst and isoform-specific function of PKC during FcgammaR-mediated phagocytosis, we used live, digital fluorescence imaging of mouse microglial cells expressing GFP-tagged molecules. betaI PKC, epsilonPKC, and diacylglycerol kinase (DGK) beta dynamically and transiently accumulated around IgG-opsonized beads (BIgG). Moreover, the accumulation of p47(phox), an essential cytosolic component of NADPH oxidase and a substrate for betaI PKC, at the phagosomal cup/phagosome was apparent during BIgG ingestion. Superoxide (O(2)(-)) production was profoundly inhibited by Gö6976, a cPKC inhibitor, and dramatically increased by the DGK inhibitor, R59949. Ultrastructural analysis revealed that BIgG induced O(2)(-) production at the phagosome but not at the intracellular granules. We conclude that activation/accumulation of betaI PKC is involved in O(2)(-) production, and that O(2)(-) production is primarily initiated at the phagosomal cup/phagosome. This study also suggests that DGKbeta plays a prominent role in regulation of O(2)(-) production during FcgammaR-mediated phagocytosis.
Ueyama
Takehiko
T
Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan.
Lennartz
Michelle R
MR
Noda
Yukiko
Y
Kobayashi
Toshihiro
T
Shirai
Yasuhito
Y
Rikitake
Kyoko
K
Yamasaki
Tomoko
T
Hayashi
Shigeto
S
Sakai
Norio
N
Seguchi
Harumichi
H
Sawada
Makoto
M
Sumimoto
Hideki
H
Saito
Naoaki
N
D000818:Animals; D002461:Cell Line, Transformed; D019852:Diacylglycerol Kinase / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D017628:Microglia / Q000201:enzymology* / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D008863:Microspheres; D016877:Oxidants / Q000096:biosynthesis; D010586:Phagocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D010587:Phagocytosis / Q000235:genetics / Q000276:immunology*; D010588:Phagosomes / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D064546:Protein Kinase C beta; D051744:Protein Kinase C-epsilon; D017452:Receptors, IgG / Q000502:physiology*; D013481:Superoxides / Q000378:metabolism*
D007527:Isoenzymes; D008164:Luminescent Proteins; D016877:Oxidants; D017452:Receptors, IgG; D013481:Superoxides; D049452:Green Fluorescent Proteins; C497256:Prkce protein, mouse; D019852:Diacylglycerol Kinase; C497255:PRKCE protein, human; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051744:Protein Kinase C-epsilon