Project description:Induction of alternative proinflammatory cytokines accounts for sustained psoriasiform skin inflammation in IL-17C+IL-6KO mice [array]
Project description:IL-6 inhibition has been unsuccessful in treating psoriasis, despite high levels of tissue and serum IL-6 in patients. Additionally, de novo psoriasis onset has been reported following IL-6 blockade in rheumatoid arthritis patients. To explore mechanisms underlying these clinical observations, we backcrossed an established psoriasiform mouse model (IL-17C+ mice) with IL-6 deficient mice (IL-17C+KO) and examined the cutaneous phenotype. IL-17C+KO mice initially exhibited decreased skin inflammation, however this decrease was transient and reversed rapidly, concomitant with increases in skin Tnf, Il36α/β/γ, Il24, epigen and S100a8/a9 to levels higher than those found in IL-17C+ mice. Comparison of IL-17C+ and IL-17C+KO mouse skin transcriptomes with that of human psoriasis skin, revealed significant correlation among transcripts of psoriasis patient skin and IL-17C+KO mouse skin, and confirmed an exacerbation of the inflammatory signature in IL-17C+KO mice that aligns closely with human psoriasis. Transcriptional analyses of IL-17C+ and IL-17C+KO primary keratinocytes confirmed increased expression of proinflammatory molecules, suggesting that in the absence of IL-6, keratinocytes increase production of numerous additional proinflammatory cytokines. These preclinical findings may provide insight into why arthritis patients being treated with IL-6 inhibitors develop new onset psoriasis and why IL-6 blockade for the treatment of psoriasis has not been clinically effective.
Project description:IL-6 inhibition has been unsuccessful in treating psoriasis, despite high levels of tissue and serum IL-6 in patients. Additionally, de novo psoriasis onset has been reported following IL-6 blockade in rheumatoid arthritis patients. To explore mechanisms underlying these clinical observations, we backcrossed an established psoriasiform mouse model (IL-17C+ mice) with IL-6 deficient mice (IL-17C+KO) and examined the cutaneous phenotype. IL-17C+KO mice initially exhibited decreased skin inflammation, however this decrease was transient and reversed rapidly, concomitant with increases in skin Tnf, Il36α/β/γ, Il24, epigen and S100a8/a9 to levels higher than those found in IL-17C+ mice. Comparison of IL-17C+ and IL-17C+KO mouse skin transcriptomes with that of human psoriasis skin, revealed significant correlation among transcripts of psoriasis patient skin and IL-17C+KO mouse skin, and confirmed an exacerbation of the inflammatory signature in IL-17C+KO mice that aligns closely with human psoriasis. Transcriptional analyses of IL-17C+ and IL-17C+KO primary keratinocytes confirmed increased expression of proinflammatory molecules, suggesting that in the absence of IL-6, keratinocytes increase production of numerous additional proinflammatory cytokines. These preclinical findings may provide insight into why arthritis patients being treated with IL-6 inhibitors develop new onset psoriasis and why IL-6 blockade for the treatment of psoriasis has not been clinically effective.
Project description:Atopic dermatitis (AD) is a serious inflammatory skin disorder characterized by increased levels of proinflammatory cytokines that contribute to a vicious cycle of inflammation. While the in-flammatory recombinant human epidermal (RHE) models related to AD have been established, there is currently lack of comprehensive understanding. To reveal the alterations and identify potential hub genes in AD-related inflammation, related RHE models induced by inflammatory cocktail (polyinosinic-polycytidylic acid, TNF-α, IL-4 and IL-13) are constructed and analyzed through TMT-proteomic in combination with RNA-seq transcriptomic.
Project description:Cyclic AMP (cAMP) has a key role in psoriasis pathogenesis, as indicated by the therapeutic efficacy of phosphodiesterase inhibitors that prevent the degradation of cAMP. However, whether soluble adenylate cyclase (sAC) (encoded by the ADCY10 gene), which is an important source for cAMP, is involved in Th17 cell-mediated inflammation or could be an alternative therapeutic target in psoriasis is unknown. We have utilized the imiquimod model of murine psoriasiform dermatitis to address this question. Adcy10-/- mice had reduced erythema, scaling and swelling in the skin and Th17 cell numbers in the draining lymph nodes, compared with wild-type mice after induction of psoriasiform dermatitis with imiquimod. During Th17 polarization in vitro, naïve T cells from Adcy10-/- mice were unable to differentiate to Th17 cells and RNA-seq analysis revealed that sAC was also essential for Th17 cell activation. Interestingly, sAC did not impact Th17 lineage-defining transcription factors (such as RORc and cMAF) but rather was required for CREB-dependent gene expression. Finally, topical application of small molecule sAC inhibitors (sACi) reduced imiquimod-induced psoriasiform dermatitis and IL17 gene expression in the skin. Collectively, these findings demonstrate that sAC is a key factor for inducing type 17 inflammation in the skin and sACi could provide an alternative class of topical therapeutics for psoriasis.
Project description:Complex interactions of keratinocytes with various cells like inflammatory cells and stromal cells contribute to the pathogenesis of chronic inflammatory dermatoses. In proinflammatory cytokines mediating such ill settings, interleukin (IL)-9 plays a pathological role in inflammatory dermatoses. However, IL-9-related mechanisms in such diseases are still incompletely understood. In this study, we established tamoxifen-induced keratinocyte-specific IL-9 receptor alpha-chain-deficient mice (K14CRE/ERTIl9ra∆/∆ mice) to examine the role of IL-9 in multicellular interactions under the condition of chronic skin inflammation. Studies using an imiquimod-induced psoriasis-like model showed that K14CRE/ERTIl9ra∆/∆ mice significantly reduced the severity of dermatitis and mast cell infiltration compared to K14WTIl9rafl/fl mice as controls. The transcriptome analyses of psoriasis-like lesions showed that the level of peptide tyrosine-tyrosine (Pyy), a member of neuropeptide Y family, was markedly downregulated in K14CRE/ERTIl9ra∆/∆ epidermis. Blockade of Pyy suppressed thickening of the epidermis and mast cell number in imiquimod-treated wild-type mice. Together with in vitro studies indicating a capacity of Pyy to induce IL-9 production and chemotactic activity of bone marrow-derived mast cells (BMMCs), these suggest that Pyy-mediated interplay of keratinocytes and mast cells induces psoriasiform inflammation. Further investigation focusing on the IL-9-Pyy axis would provide a new modality for treatment of chronic inflammatory dermatoses.
Project description:The IL-23/IL-17 immune axis is of central importance in psoriasis. However, the contribution of IL-17 family cytokines other than IL-17A to drive skin inflammation in psoriasis has not been fully established. To further elucidate the role of individual IL-17 family cytokines in psoriasis, we investigated their expression and localization in psoriasis skin at the mRNA and protein level. Moreover, we investigated the gene expression signatures induced by individual IL-17 family cytokines in human skin ex vivo as well as modulation of responses induced by the combination of IL-17 family cytokines in human keratinocytes by brodalumab, a human monoclonal antibody targeting the IL-17RA, versus the IL-17A blocking antibody ixekizumab. We demonstrate that IL-17A, IL-17AF, IL-17F and IL-17C are expressed at increased levels in psoriasis lesional skin and induce inflammatory gene expression signatures in human skin ex vivo that correlate with those observed in psoriasis. Furthermore, we show that brodalumab, in contrast to ixekizumab, fully blocks gene expression responses induced by the combination of IL-17A, IL-17AF, IL-17F and IL-17C in human keratinocytes. These findings suggest that inhibition of several IL-17 family cytokines, e.g. by targeting of the IL-17RA receptor, could be a favored mechanism to obtain a profound suppression of the inflammatory processes in psoriasis and thereby achieve high levels of skin clearance and sustained efficacy in patients with psoriasis.
Project description:GM-CSF paradoxically possesses ability to differentiate both classically activated macrophages (MØs) with dominant proinflammatory function (M1-like MØs) and alternative activated MØs with strong immunosuppressive function (M2-like MØs). The intrinsic regulatory mechanism responsible for functional polarization of MØs under GM-CSF signalling remains elusive. Here we revealed that cytokine-inducible SH2-containing protein (CIS), induced by GM-CSF, is a key determinant in controlling MØ polarization. Compared to WT MØs, Cish-/- MØs gained characteristics of alternative activated MØs (M2 MØs), showing high expression of prototypic M2 markers Arginase 1, Tgm2 and YM-1; strong suppression of T cell proliferation; and low production of IL-12 and other proinflammatory cytokines¬¬. Differing from canonical IL-4/STAT6/IRF4 signaling axis of M2 induction, development of M2 MØ characteristics in Cish-/- MØs was associated with intensified STAT5 activation and consequent IRF8 downregulation. Attenuation of GM-CSF signalling via JAK inhibition and IRF8 rescue corrected certain functional defects in Cish-/- MØs. As CIS inhibition in NK and T cells promotes anti-tumour immunity, we showed that CIS deficiency enhanced the development of intra-tumoural M2 MØs and reduced CTL induction within tumour microenvironment with elevated GM-CSF. Overall, we conclude that CIS acts as an intrinsic rheostat to control intense GM-CSF signalling in order to maintain proinflammatory functions of MØs. Targeting CIS as a checkpoint in cancer immunotherapy should consider its role in regulating myeloid cell function.