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Activation of NFkB with Serine Phosphorylation by Otitis Media Pathogens in Epithelial Cells
Author(s) -
Moon Sung K.,
Woo JeongIm,
Pan Huiqi,
Lee HaaYung,
Gellibolian Robert,
Lim David J.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.826.4
Subject(s) - phosphorylation , signal transduction , serine , biology , pathogen , microbiology and biotechnology , immunology
Rel/NFkB proteins are required for regulating genes related to inflammation. Recently, we showed that activation of p65 is involved in nontypeable Haemophilus influenzae (NTHi)‐induced MCP‐1 up‐regulation in the spiral ligament fibrocytes (Moon et al, 2007). We aim to elucidate the specific subunits of NFkB activated upon exposure to otitis media (OM) pathogens such as NTHi and S. pneumoniae (SP) and to identify the phosphorylated serine residue of the NFkB subunits involved. Luciferase assay was performed with vectors containing multiple copies of the NFkB consensus sequence, demonstrating that NFkB is activated upon exposure to OM pathognes. Immunolabeling showed that p65, p105/p50 and Rel‐B were translocated to the nucleus upon exposure to NTHi, SP or TNF. In contrast, p100/p52 and c‐Rel were not activated upon exposure to OM pathogens. Immunoblotting showed that Ser536 of p65 and Ser933 of p105 are phosphorylated upon exposure to NTHi, SP or TNF. Interestingly, Ser468 and Ser276 of p65 were phosphorylated by SP or TNF, but not by NTHi. TNF showed a faster kinetics in activating NFkB than NTHi or SP. Gene Arrays demonstrated that SP up‐regulates IkBa and RhoA compared to NTHi. It is suggested that a variety of signaling pathways are involved in OM pathogen‐induced NFkB activation. Identifying the pathogen‐activated NFkB with signaling pathways will enables us to better understand host‐pathogen interactions.