An analysis of IL-36 signature genes and individuals with IL1RL2 knockout mutations validates IL-36 as a psoriasis therapeutic target
SCIENCE TRANSLATIONAL MEDICINE
Authors: Mahil, Satveer K.; Catapano, Marika; Di Meglio, Paola; Dand, Nick; Ahlfors, Helena; Carr, Ian M.; Smith, Catherine H.; Trembath, Richard C.; Peakman, Mark; Wright, John; Ciccarelli, Francesca D.; Barker, Jonathan N.; Capon, Francesca
Abstract
Interleukin (IL)-36a, IL-36b, and IL-36g are innate mediators of acute epithelial inflammation. We sought to demonstrate that these cytokines are also required for the pathogenesis of plaque psoriasis, a common and chronic skin disorder, caused by abnormal T helper 17 (T(H)17) cell activation. To investigate this possibility, we first defined the genes that are induced by IL-36 cytokines in primary human keratinocytes. This enabled us to demonstrate a significant IL-36 signature among the transcripts that are up-regulated in plaque psoriasis and the susceptibility loci associated with the disease in genome-wide studies. Next, we investigated the impact of in vivo and ex vivo IL-36 receptor blockade using a neutralizing antibody or a recombinant antagonist. Both inhibitors had marked anti-inflammatory effects on psoriatic skin, demonstrated by statistically significant reductions in IL-17 expression, keratinocyte activation, and leukocyte infiltration. Finally, we explored the potential safety profile associated with IL-36 blockade by phenotyping 12 individuals carrying knockout mutations of the IL-36 receptor gene. We found that normal immune function was broadly preserved in these individuals, suggesting that IL-36 signaling inhibition would not substantially compromise host defenses. These observations, which integrate the results of transcriptomics and model system analysis, pave the way for early-stage clinical trials of IL-36 antagonists.
IL-36R signaling integrates innate and adaptive immune-mediated protection against enteropathogenic bacteria
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Authors: Ngo, Vu L.; Abo, Hirohito; Kuczma, Michal; Szurek, Edyta; Moore, Nora; Medina-Contreras, Oscar; Nusrat, Asma; Merlin, Didier; Gewirtz, Andrew T.; Ignatowicz, Leszek; Denning, Timothy L.
Abstract
Enteropathogenic bacterial infections are a global health issue associated with high mortality, particularly in developing countries. Efficient host protection against enteropathogenic bacterial infection is characterized by coordinated responses between immune and nonimmune cells. In response to infection in mice, innate immune cells are activated to produce interleukin (IL)-23 and IL-22, which promote antimicrobial peptide (AMP) production and bacterial clearance. IL-36 cytokines are proinflammatory IL-1 superfamily members, yet their role in enteropathogenic bacterial infection remains poorly defined. Using the enteric mouse pathogen, C. rodentium, we demonstrate that signaling via IL-36 receptor (IL-36R) orchestrates a crucial innate-adaptive immune link to control bacterial infection. IL-36R-deficient mice (Il1rl2(-/-)) exhibited significant impairment in expression of IL-22 and AMPs, increased intestinal damage, and failed to contain C. rodentium compared to controls. These defects were associated with failure to induce IL-23 and IL-6, two key IL-22 inducers in the early and late phases of infection, respectively. Treatment of Il1rl2(-/-) mice with IL-23 during the early phase of C. rodentium infection rescued IL-22 production from group 3 innate lymphoid cells (ILCs), whereas IL-6 administration during the late phase rescued IL-22-mediated production from CD4(+) T cell, and both treatments protected Il1rl2(-/-) mice from uncontained infection. Furthermore, IL-36R-mediated IL-22 production by CD4(+) T cells was dependent upon NF kappa B-p65 and IL-6 expression in dendritic cells (DCs), as well as aryl hydrocarbon receptor (AhR) expression by CD4(+) T cells. Collectively, these data demonstrate that the IL-36 signaling pathway integrates innate and adaptive immunity leading to host defense against enteropathogenic bacterial infection.