A serine/threonine kinase, Cot/Tpl2, modulates bacterial DNA–induced IL-12 production and Th cell differentiation
Kenji Sugimoto, … , Yasuhiro Shimada, Tetsuya Matsuguchi
Kenji Sugimoto, … , Yasuhiro Shimada, Tetsuya Matsuguchi
Published September 15, 2004
Citation Information: J Clin Invest. 2004;114(6):857-866. https://doi.org/10.1172/JCI20014.
View: Text | PDF
Article Immunology

A serine/threonine kinase, Cot/Tpl2, modulates bacterial DNA–induced IL-12 production and Th cell differentiation

Abstract

A serine/threonine protein kinase, Cot/Tpl2, is indispensable for extracellular signal–regulated kinase (ERK) activation and production of TNF-α and PGE2 in LPS-stimulated macrophages. We show here that Cot/Tpl2 is also activated by other Toll-like receptor (TLR) ligands. Bacterial DNA rich in the dinucleotide CG (CpG-DNA), unlike LPS or synthetic lipopeptide, activated ERK in a Cot/Tpl2–independent manner. Peritoneal macrophages and bone marrow–derived DCs from Cot/Tpl2–/– mice produced significantly more IL-12 in response to CpG-DNA than those from WT mice. Enhanced IL-12 production in Cot/Tpl2–/– macrophages is, at least partly, regulated at the transcriptional level, and the elevated IL-12 mRNA level in Cot/Tpl2–/– macrophages is accompanied by decreased amounts of IL-12 repressors, such as c-musculoaponeurotic fibrosarcoma (c-Maf) and GATA sequence in the IL-12 promoter–binding protein (GA-12–binding protein; GAP-12) in the nucleus. Consistently, Cot/Tpl2–/– mice showed Th1-skewed antigen-specific immune responses upon OVA immunization and Leishmania major infection in vivo. These results indicate that Cot/Tpl2 is an important negative regulator of Th1-type adaptive immunity, that it achieves this regulation by inhibiting IL-12 production from accessory cells, and that it might be a potential target molecule in CpG-DNA–guided vaccination.

Authors

Kenji Sugimoto, Mutsuhiro Ohata, Jun Miyoshi, Hiroyoshi Ishizaki, Naotake Tsuboi, Akio Masuda, Yasunobu Yoshikai, Masaya Takamoto, Kazuo Sugane, Seiichi Matsuo, Yasuhiro Shimada, Tetsuya Matsuguchi

×

Figure 6

Options: View larger image (or click on image) Download as PowerPoint
Antigen-specific Th1 cell responses were enhanced in Cot/Tpl2–/– mice. (...
Antigen-specific Th1 cell responses were enhanced in Cot/Tpl2–/– mice. (A) Lymph node cells were collected from WT (filled circles, n = 4) or Cot/Tpl2–/– mice (open circles, n = 4) on day 9 after immunization with OVA in CFA. Proliferation of antigen-specific T cells was analyzed by cell proliferation assay using cell culture supernatants in different concentrations of OVA for 72 hours. (B) CD4+ T cells from lymph nodes of WT (black bars, n = 4) or Cot/Tpl2–/– mice (white bars, n = 4) immunized with OVA in CFA were cultured in different concentrations of OVA with APCs for 72 hours. Cytokines in supernatants of antigen-stimulated pooled cells were determined by specific ELISA. (C and D) Serum was collected from WT (filled circles, n = 5) and Cot/Tpl2–/– mice (open circles, n = 5) before (day 0) and after (day 9) immunization with OVA plus CFA (C) or OVA plus alum (D). OVA-specific IgG2a, OVA-specific IgG1, and OVA-specific IgE were analyzed. The y axis indicates the OD value at 492 nm. (E) CD4+ T cells from lymph nodes of WT (black bars, n = 3) or Cot/Tpl2–/– mice (white bars, n = 3) immunized with OVA plus LPS or OVA plus CpG-DNA were cultured in the presence of OVA (1 mg/ml) with APCs for 72 hours. Cytokines in supernatants of antigen-stimulated pooled cells were determined by specific ELISA. Data are expressed as mean of wells ± SD and are representative of 3 independent experiments. *P < 0.05.