First Author | Johnson J | Year | 2011 |
Journal | Mol Immunol | Volume | 48 |
Issue | 12-13 | Pages | 1484-93 |
PubMed ID | 21550664 | Mgi Jnum | J:172365 |
Mgi Id | MGI:5007563 | Doi | 10.1016/j.molimm.2011.04.006 |
Citation | Johnson J, et al. (2011) A conventional protein kinase C inhibitor targeting IRF-3-dependent genes differentially regulates IL-12 family members. Mol Immunol 48(12-13):1484-93 |
abstractText | Protein kinase C (PKC) isoforms play a critical role in the regulation of innate immune responses. We have previously demonstrated that conventional PKC (cPKC) alpha is involved in interferon regulatory factor 3 (IRF-3) activation and IFN-beta synthesis. Herein, we investigated the role of cPKCs in the regulation of IL-12 family members expression mediated by the Toll-like receptor 3 (TLR3) and TLR4. First, inhibition of cPKCs activity in human DCs by a cPKC-specific inhibitor, Go6976 downregulated the expression of IL-12p70 and IL-27p28 but not IL-12/IL-23p40, IL-23, IL-27EBI3 induced by LPS or poly(I:C). Furthermore, reporter gene assays in RAW 264.7 macrophages showed that cPKCs regulate IL-12p35 and IL-27p28 promoter activities since Go6976 repressed LPS and poly(I:C)-mediated transcriptional activities of IL-12p35 and IL-27p28. In contrast, no effect was observed with IL-12/IL-23p40 and IL-23p19 reporter constructs. These results prompted us to study the role of IRF-3 on IL-23 expression. Bone marrow-derived DC (BMDCs) from IRF-3(-/-) mice produced comparable levels of IL-23 induced by both LPS and poly(I:C) as compared to wild type BMDCs, indicating that IRF-3 is not involved in IL-23 production. Finally, BMDCs from PKCalpha(-/-) mice displayed a reduced synthesis of IL-27 induced by poly(I:C). Collectively, these data identify cPKCs as critical components that control IRF-3-dependent IL-12p35 and IL-27p28 gene expression downstream of TLR3 and TLR4. |