| First Author | Zheng M | Year | 2016 |
| Journal | Infect Immun | Volume | 84 |
| Issue | 3 | Pages | 782-9 |
| PubMed ID | 26729763 | Mgi Jnum | J:237979 |
| Mgi Id | MGI:5817817 | Doi | 10.1128/IAI.01268-15 |
| Citation | Zheng M, et al. (2016) Therapeutic Role of Interleukin 22 in Experimental Intra-abdominal Klebsiella pneumoniae Infection in Mice. Infect Immun 84(3):782-9 |
| abstractText | Interleukin 22 (IL-22) is an IL-10-related cytokine produced by T helper 17 (Th17) cells and other immune cells that signals via IL-22 receptor alpha 1 (IL-22Ra1), which is expressed on epithelial tissues, as well as hepatocytes. IL-22 has been shown to have hepatoprotective effects that are mediated by signal transducer and activator of transcription 3 (STAT3) signaling. However, it is unclear whether IL-22 can directly regulate antimicrobial programs in the liver. To test this hypothesis, hepatocyte-specific IL-22Ra1 knockout (Il22Ra1(Hep-/-)) and Stat3 knockout (Stat3(Hep-/-)) mice were generated and subjected to intra-abdominal infection with Klebsiella pneumoniae, which results in liver injury and necrosis. We found that overexpression of IL-22 or therapeutic administration of recombinant IL-22 (rIL-22), given 2 h postinfection, significantly reduced the bacterial burden in both the liver and spleen. The antimicrobial activity of rIL-22 required hepatic Il22Ra1 and Stat3. Serum from rIL-22-treated mice showed potent bacteriostatic activity against K. pneumoniae, which was dependent on lipocalin 2 (LCN2). However, in vivo, rIL-22-induced antimicrobial activity was only partially reduced in LCN2-deficient mice. We found that rIL-22 also induced serum amyloid A2 (SAA2) and that SAA2 had anti-K. pneumoniae bactericidal activity in vitro. These results demonstrate that IL-22, through IL-22Ra1 and STAT3 singling, can induce intrinsic antimicrobial activity in the liver, which is due in part to LCN2 and SAA2. Therefore, IL-22 may be a useful adjunct in treating hepatic and intra-abdominal infections. |
