First Author | Kitamura H | Year | 2005 |
Journal | Immunity | Volume | 23 |
Issue | 5 | Pages | 491-502 |
PubMed ID | 16286017 | Mgi Jnum | J:113335 |
Mgi Id | MGI:3665416 | Doi | 10.1016/j.immuni.2005.09.010 |
Citation | Kitamura H, et al. (2005) IL-6-STAT3 controls intracellular MHC class II alphabeta dimer level through cathepsin S activity in dendritic cells. Immunity 23(5):491-502 |
abstractText | We found IL-6-STAT3 pathway suppresses MHC class II (MHCII) expression on dendritic cells (DCs) and attenuates T cell activation. Here, we showed that IL-6-STAT3 signaling reduced intracellular MHCII alphabeta dimmer, Ii, and H2-DM levels in DCs. IL-6-mediated STAT3 activation decreased cystatin C level, an endogenous inhibitor of cathepsins, and enhanced cathepsin activities. Importantly, cathepsin S inhibitors blocked reduction of MHCII alphabeta dimer, Ii, and H2-DM in the IL-6-treated DCs. Overexpression of cystatin C suppressed IL-6-STAT3-mediated increase of cathepsin S activity and reduction of MHCII alphabeta dimer, Ii, and H2-DM levels in DCs. Cathepsin S overexpression in DCs decreased intracellular MHCII alphabeta dimer, Ii, and H2-DM levels, LPS-mediated surface expression of MHCII and suppressed CD4(+) T cell activation. IL-6-gp130-STAT3 signaling in vivo decreased cystatin C expression and MHCII alphabeta dimer level in DCs. Thus, IL-6-STAT3-mediated increase of cathepsin S activity reduces the MHCII alphabeta dimer, Ii, and H2-DM levels in DCs, and suppresses CD4(+) T cell-mediated immune responses. |