Polymorphisms of interleukin (IL)-23R and signaling components are associated with several autoimmune diseases, including inflammatory bowel diseases (IBD). Similar to T helper type 17 (Th17) lineage, type 3 innate lymphoid cells (ILCs) express retinoic acid–related orphan receptor γt (Rorγt) and IL-23R and hence, produce Th17-type cytokines. Recent reports implicated type 3 ILCs in IBD; however, how IL-23R signaling in these cells contributes to pathogenesis is unknown. IL-22, produced in copious amounts by type 3 ILCs, was reported to have both beneficial and pathogenic effects in adaptive, yet only a protective role in innate colitis models. Herein, by employing chronic CD45RBhigh CD4+ T-cell transfer and anti-CD40 antibody-induced acute innate colitis models in Rag1−/− mice, wedemonstrated opposite roles for IL-23R in colitogenesis: in the former a protective, and in the latter a pathogenic role. Furthermore, we show that IL-23R signaling promotes innate colitis via IL-22 as neutralization of IL-22 protected mice from colitis and adding back of IL-22 to IL-23R-deficient animals restored the disease. Collectively, our results reveal that similar to its controversial role during chronic or adaptive colitis, IL-22 may also have opposite roles in innate colitis pathogenesis in a context and insult-dependent manner.

Hepatitis C virus infection affects 170 million people worldwide and the majority of individuals exposed to HCV develop chronic hepatitis leading to progressive liver damage, cirrhosis and hepatocellular cancer. The natural history of HCV infection is influenced by genetic and environmental factors of which chronic alcohol use is an independent risk factor for cirrhosis in HCV infected individuals. Both the hepatitis C virus and alcohol damage the liver and result in immune alterations contributing to both decreased viral clearance and liver injury. This review will capture the major components of the interactions between alcohol and HCV infection to provide better understanding for the molecular basis of the dangerous combination of alcohol use and HCV infection. Common targets of HCV and alcohol involve innate immune recognition and dendritic cells, the critical cell type in antigen presentation and antiviral immunity. In addition, both alcohol and HCV affect intracellular processes critical for hepatocyte and immune cell functions including mitochondrial and proteasomal activation. Finally, both chronic alcohol use and hepatitis C virus infection increase the risk of hepatocellular cancer. The common molecular mechanisms underlying the pathological interactions between alcohol and HCV include the modulation of cytokine production, lipopolysaccharide (LPS)-TLR4 signaling, and reactive oxygen species (ROS) production. LPS-induced chronic inflammation is not only a major cause of progressive liver injury and fibrosis but it can also contribute to modification of the tissue environment and stem cells to promote hepatocellular cancer development. Alteration of these # Corresponding authors: