IL-22 is required for Th17 cell–mediated pathology in a mouse model of psoriasis-like skin inflammation

Abstract

Psoriasis is a chronic skin disease resulting from the dysregulated interplay between keratinocytes and infiltrating immune cells. We report on a psoriasis-like disease model, which is induced by the transfer of CD4 + CD45RB hi CD25 -cells to pathogen-free scid/scid mice. Psoriasis-like lesions had elevated levels of antimicrobial peptide and proinflammatory cytokine mRNA. Also, similar to psoriasis, disease progression in this model was dependent on the p40 common to IL-12 and IL-23. To investigate the role of IL-22, a Th17 cytokine, in disease progression, mice were treated with IL-22-neutralizing antibodies. Neutralization of IL-22 prevented the development of disease, reducing acanthosis (thickening of the skin), inflammatory infiltrates, and expression of Th17 cytokines. Direct administration of IL-22 into the skin of normal mice induced both antimicrobial peptide and proinflammatory cytokine gene expression. Our data suggest that IL-22, which acts on keratinocytes and other nonhematopoietic cells, is required for development of the autoreactive Th17 cell-dependent disease in this model of skin inflammation. We propose that IL-22 antagonism might be a promising therapy for the treatment of human psoriasis. IntroductionPsoriasis is a common, chronic autoimmune disease of the skin, which affects approximately 2% of the general population. The lesions are characterized by red, scaly, raised plaques at different body sites. Histologically, psoriasis is defined by thickening of the epidermis (acanthosis) due to increased proliferation of keratinocytes, epidermal rete peg formation (downward papillary projections of the epidermis), and parakeratosis (retention of keratinocyte nuclei in the stratum corneum) as well as inflammatory cell infiltrates in the epidermis and dermis (1). Psoriasis does not exist as a spontaneously occurring disease in the skin of animals other than humans. Although some features of psoriasis have been induced in mouse skin by genetic or immune manipulations, these previously described models do not have the full histopathological or immunological features of psoriatic lesions (2-6). In one model, Hong et al. adoptively transferred CD4 + CD45RB hi T cells into scid/scid recipient mice. Disease severity and incidence in this model were mild and improved by coadministration of IL-12 and LPS during disease induction (7). We have validated this model and developed it further by adoptively transferring CD4 + CD45RB hi T cells depleted of CD25 + regulatory cells into scid/scid recipient mice. Affected mice developed scaly and raised skin plaques with certain microscopic characteristics resembling human psoriasis.Although the exact cause of psoriasis is unknown, the data suggest that this disease is caused by a dysregulated interplay between keratinocytes and inflammatory cell infiltrates. This dysregulation results in the production of inflammatory cytokines and chemokines that

NK Cells Influence Both Innate and Adaptive Immune Responses after Mucosal Immunization with Antigen and Mucosal Adjuvant

“…crucial for IL-6 production in various disease states (50,51). This finding suggests that IL-22 production via NALT and CLN NK cells shortly after i.n.…”

Selective functional inhibition of JAK‐3 is sufficient for efficacy in collagen‐induced arthritis in mice

“…B6129SF2/J mice (n ϭ 10) were dosed orally with vehicle (2% Tween 80, 0.5% methylcellulose), WYE-151650, or CP-690,550, or intraperitoneally with anti-IL-22 antibody (generated internally, clone Ab-01) (19). One hour later, mice were injected intraperitoneally with 10 g of recombinant mouse IL-22 (20).…”

Activation of the aryl hydrocarbon receptor reveals distinct requirements for IL‐22 and IL‐17 production by human T helper cells

“…In the mouse, IL-23 was shown to drive preferential expansion of cells that co-express IL-22 and IL-17, that may synergize to augment the expression of genes involved in defense against microbial pathogens [13,14]. However, several mouse models of infection and autoimmunity suggested distinct roles for IL-17 and IL-22 [15][16][17][18][19].…”