Interleukin-8 induction via NF-kappaB, p38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2 pathways in human peripheral blood mononuclear cells by Alloiococcus otitidis.
Alloiococcus otitidis is a newly recognized species of gram-positive bacteria frequently associated with otitis media. Although immunostimulating activity of this organism has been investigated, little is known about the signaling pathways of chemokine/cytokine induction by this organism. We investigated the role of NF-kappaB and mitogen-activated protein (MAP) kinases in chemokine interleukin-8 (IL-8) production by human peripheral blood mononuclear cells (PBMCs) after stimulation with A. otitidis. The organism could induce in vitro IL-8 production in human PBMCs. I kappa B alpha, NF-kappaB, p38 MAP kinase, p44/42 MAP kinase (ERK1/2) became phosphorylated in PBMCs after stimulation with A. otitidis. And, inhibitors of NF-kappaB (caffeic acid phenylethyl ester), p38 (SB 203580), or ERK1/2 (PD 98059) significantly reduced IL-8 induction by the organism. These results were similar to findings in IL-8 induction by Streptococcus pneumoniae, another gram-positive major middle ear pathogen. Our preliminary study suggests that multiple pathways including NF-kappaB, p38, and ERK1/2 were simultaneously activated, and were associated with IL-8 induction by A. otitidis in human PBMCs.
Harimaya
Atsushi
A
Department of Otolaryngology, Sapporo Medical University School of Medicine, S-1, W-16, Chuo-ku, Sapporo, Hokkaido 060-8543, Japan. harimaya@sapmed.ac.jp
Koizumi
Jun-ichi
J
Fujii
Nobuhiro
N
Himi
Tetsuo
T
D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D016908:Gram-Positive Bacterial Infections / Q000150:complications* / Q000235:genetics*; D006801:Humans; D016209:Interleukin-8 / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000201:enzymology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics* / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics* / Q000378:metabolism*; D016328:NF-kappa B / Q000235:genetics* / Q000378:metabolism*; D010033:Otitis Media / Q000235:genetics* / Q000382:microbiology*; D015398:Signal Transduction / Q000502:physiology*; D013296:Streptococcus pneumoniae / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism*
D016209:Interleukin-8; D016328:NF-kappa B; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases