RNA-seq analysis of IL-1B and IL-36 responses in epidermal keratinocytes identifies a shared MyD88-dependent gene signature
Ontology highlight
ABSTRACT: IL-36 cytokines have recently emerged as mediators of inflammation in autoimmune conditions including psoriasis vulgaris (PsV) and generalized pustular psoriasis (GPP). This study used RNA-seq to profile the transcriptome of primary epidermal keratinocytes (KCs) treated with IL-1B, IL-36A, IL-36B or IL-36G. We identified some early IL-1B-specific responses (8 hours post-treatment), but nearly all late IL-1B responses were replicated by IL-36 cytokines (24 hours post-treatment). Type I and II interferon genes exhibited time-dependent response patterns, with early induction (8 hours) followed by no response or repression (24 hours). Altogether, we identified 225 differentially expressed genes (DEGs) with shared responses to all 4 cytokines at both time points (8 + 24 hours). These involved up-regulation of ligands (IL1A, IL1B, IL36G) and activating proteases (CTSS), but also up-regulation of inhibitors such as IL1RN and IL36RN. Shared IL-1B/IL-36 DEGs overlapped significantly with genes altered in PsV and GPP skin lesions, as well as genes near GWAS loci linked to autoimmune and autoinflammatory diseases (e.g., PsV, psoriatic arthritis, IBD, primary biliary cholangitis). Inactivation of MyD88 adapter protein using CRISPR/Cas9 completely abolished expression responses of such DEGs to IL-1B and IL-36G stimulation. These results provide a global view of IL-1B and IL-36 expression responses in epidermal KCs with fine-scale characterization of time-dependent and cytokine-specific response patterns. Our findings support an important role for IL-1B and IL-36 in autoimmune or autoinflammatory conditions and show that MyD88 adaptor protein mediates shared IL-1B/IL-36 responses.
Project description:Generalized pustular psoriasis (GPP) is a rare, debilitating, and often life-threatening inflammatory disease characterized by episodic infiltration of neutrophils into the skin, pustule development, and systemic inflammation, which can manifest in the presence or absence of chronic plaque psoriasis (PV). Current treatments are unsatisfactory thus a better understanding the pathogenesis of GPP is warranted. To assess the pathophysiological differences between GPP and PV we performed a gene expression study on formalin-fixed paraffin-embedded biopsies of GPP (n=30) and PV (n=12) lesions and healthy control (n=20) skin. Compared with healthy skin, GPP lesions yielded 365 and PV 898 differentially expressed genes respectively, with 190 upregulated in both diseases. We detected higher expression of IL-1 and IL-36 cytokines in GPP lesions compared with PV, and this occurred proximal to neutrophils. We show both activated neutrophils and isolated neutrophil proteases can activate IL-36. Diverging from the Th1/Th17 pathophysiology of PV, significantly fewer IL23A, IL17A, IFNG, CXCL9, CXCL10 and MX1 transcripts were detected in GPP lesions. Our data indicate a level of sustained activation of IL-1 and IL-36 in GPP, inducing neutrophil chemokine expression, infiltration and pustule formation, suggesting that the IL-1 and IL-36 inflammatory axes are the main drivers of disease pathology in GPP.
Project description:Generalized pustular psoriasis (GPP) is a severe disease featured by neutrophilic pustules and enhanced IL-36 inflammatory pathway in skin. Recently, a transcriptomic analysis of PBMCs and neutrophils in MPO-deficient GPP patients has been performed in stable disease state. However, transcriptomic profiling of PBMCs during acute flare of GPP is unclear. Here, we reported a predominant neutrophil signature in GPP PBMC and a marked increase in the CD66+CD16+ low-density neutrophils (LDNs) within the PBMC fraction of acute GPP patients. Transcriptomic and functional analysis of LDNs revealed a hypoinflammatory phenotype yet enhanced release of neutrophil granule proteases, implicating that LDNs might contribute to the IL-36-mediated inflammation in GPP patients.
Project description:Generalized pustular psoriasis (GPP) is a severe disease featured by neutrophilic pustules and enhanced IL-36 inflammatory pathway in skin. Recently, a transcriptomic analysis of PBMCs and neutrophils in MPO-deficient GPP patients has been performed in stable disease state. However, transcriptomic profiling of PBMCs during acute flare of GPP is unclear. Here, we reported a predominant neutrophil signature in GPP PBMC and a marked increase in the CD66+CD16+ low-density neutrophils (LDNs) within the PBMC fraction of acute GPP patients. Transcriptomic and functional analysis of LDNs revealed a hypoinflammatory phenotype yet enhanced release of neutrophil granule proteases, implicating that LDNs might contribute to the IL-36-mediated inflammation in GPP patients.
Project description:Interleukin-1B (IL-1B) is pathologically activated by inflammasome-associated caspase-1 in rare autoinflammatory conditions and in wide-spread diseases. Therefore, IL-1B activity must be fine-tuned to enable anti-microbial responses whilst limiting collateral damage. Here we report that, relative to other inflammasome components, IL-1B is rapidly turned over by the proteasome and this correlates with its decoration by K11-, K63- and K48-linked ubiquitin chains. This IL-1 degradation signal is not only a feature of inflammasome priming but is also triggered upon inflammasome activation. We demonstrate that IL-1 K133 is modified by ubiquitin and forms a salt bridge with IL-1B D129. Loss of IL-1 K133 ubiquitylation, or disruption of the K133:D129 electrostatic interaction, stabilizes IL-1Bprotein levels. Accordingly, IL-1B K133R/K133R mice display increased precursor IL-1Bupon inflammasome priming and increased bioactive IL-1B following inflammasome activation, both in vitro and following LPS injection in vivo. These findings reveal new mechanisms for limiting IL-1B activity and safeguarding against damaging inflammation.
Project description:We stimulated T-cell blasts from IL23R R381Q homozygotes (n = 2), healthy controls homozygous for the ancestral allele (n = 9), homozygous individuals for TYK2 P1104A (n = 2) that selectively impairs responses to IL-23, and one patient each with autosomal recessive, complete TYK2 or IL-12Rb1 deficiency with IL-12, IL-23, IL-1b, and IL-1b plus IL-23 for 6 hours and performed RNA-sequencing. We used IL-1b as an IL-23-sensitizing agent as previously reported. We found that while T-cell blasts from IL23R R381Q homozygotes respond normally to IL-12 and IL-1b, their response to IL-23 and to IL-23 plus IL-1b is impaired
Project description:Loss-of-function mutations in the IL36RN gene encoding IL-36 receptor antagonist (IL-36RA) cause familial generalized pustular psoriasis (GPP), which sometimes begins shortly after birth and is difficult to treat, and its effects on the epidermis are unclear. This study aimed to investigate the involvement of IL-36 receptor agonists in the epidermal formation of GPP. In this study, we found that IL-36 receptor agonists, especially mature IL-36γ, stimulate IL-8 and proIL-36γ production in the epidermis, while down-regulating the genes encoding epidermal cornified envelope-related proteins such as corneodesmosin. IL-36 receptor antagonists and monoclonal anti-IL-36γ antibodies counteract the effect of mature IL-36γ on corneodesmosin in keratinocytes in a dose-dependent manner. In the epidermis of generalized pustular psoriasis patients with IL36RN loss-of-function mutations, proIL-36γ is overproduced in the epidermis and corneodesmosin protein expression is markedly decreased in the region of giant subcorneal pustules called Kogoj’s spongiform pustules with high neutrophil infiltration. IL-8 induced by mature IL-36γ induces several neutrophils in the epidermis, and the newly produced proIL-36γ is cleaved to the mature form by neutrophil proteases. This newly produced mature IL-36γ was predicted to further suppress the gene expression of the granulosa-stratum-associated protein, corneodesmosin, leading to significant stratum corneum exfoliation and formation of giant subcorneal pustules. Overall, our results elucidate the mechanism underlying the formation of Kogoj’s spongiform pustules in generalized pustular psoriasis.
Project description:Introduction: Intestinal epithelial cells (IECs) constitute a critical first line of defense against microbes by providing a physical barrier capable of producing antimicrobial peptides (AMPs) and cytokines. While IECs are known to respond to various microbial signals, the precise upstream cues regulating diverse IEC responses are not clear. Method: Mouse intestinal crypts were isolated from colon tissue. Crypts were differentiated into 3D spheroids in matrigel by stimulating with LWRN media and growth factors. After differentiation colonoids were stimulated with IL-1b, IL-22, or IL-1b and IL-22 for 12 hours then RNA was isolated for RNA sequencing. Conclusion: Transcriptional profiling of mColonoids reveals IL-1b synergizes with IL-22 to induced a unique gene profile
Project description:The immunopathogenesis of psoriasis, a common chronic inflammatory disease of the skin, is incompletely understood. Here we demonstrate, using a combination of single cell and spatial RNA sequencing, IL-36 dependent amplification of IL-17A and TNF inflammatory responses in the absence of neutrophil proteases, which primarily occurred within the supraspinous layer of the psoriatic epidermis. We further show that a subset of SFRP2+ fibroblasts in psoriasis contribute to amplification of the immune network through transition to a pro-inflammatory state. The SFRP2+ fibroblast communication network involves production of CCL13, CCL19 and CXCL12, connected by ligand-receptor interactions to other spatially proximate cell types: CCR2+ myeloid cells, CCR7+ LAMP3+ dendritic cells, and CXCR4 expressed on both CD8+ Tc17 cells and keratinocytes, respectively. The SFRP2+ fibroblasts also express cathepsin S, further amplifying inflammatory responses by activating IL-36G in keratinocytes. These data provide an unprecedented view of psoriasis pathogenesis, which expands our understanding of the critical cellular participants to include inflammatory fibroblasts and their cellular interactions.
Project description:Background: Based on the mounting evidence that Type 17 T-cells (T17 cells) and increased IL-17 play a key role in driving hidradenitis suppurativa (HS) lesion development, biologics previously used in psoriasis that block signaling of IL-17A and/or IL-17F isoforms have been repurposed to treat HS. Objective: Our aim was to characterize the transcriptome of HS T17 cells compared to the transcriptome of psoriasis T17 cells, and their ligand-receptor interactions with neighborhood immune cell subsets. Methods: Single-cell data of 12,300 cutaneous immune cells from 8 de-roofing surgical HS skin samples that included dermal tunnels were compared with single-cell data of psoriasis skin (19,525 cells from 11 samples) and control skin (11,920 cells from 10 samples). All the single-cell data were generated by the identical protocol. Results: HS T17 cells expressed lower levels of IL23R and higher levels of IL1R1 and IL17F compared to psoriasis T17 cells (p < 0.05). HS regulatory T-cells (Tregs) expressed higher levels of IL1R1 and IL17F compared to psoriasis Tregs (p < 0.05). Semimature dendritic cells (DCs) were the major immune cell subsets expressing IL1B in HS, and IL-1B ligand-receptor interactions between semimature DCs and T17 cells were increased in HS compared to psoriasis (p < 0.05). HS dermal tunnel keratinocytes (KCs) expressed inflammatory cytokines (IL17C, IL1A, IL1B, and IL6) different from HS epidermis KCs (IL36G) (p < 0.05). IL6, which synergizes with IL1B to maintain cytokine expression in T17 cells, was mainly expressed by fibroblasts in HS, which also expressed IL11+ inflammatory fibroblast genes (IL11, IL24, IL6, and POSTN) involved in paracrine IL-1/IL-6 loop. Conclusion: The IL-1B-T17 cell cytokine axis is likely a dominant pathway in HS with HS T17 cells activated by IL-1B signaling, unlike psoriasis T17 cells which are activated by IL-23 signaling. Clinical Implication: Biologics targeting IL-17 isoforms and IL-1B may be effective for HS but biologics targeting IL-23 may be less effective for HS.
Project description:Deficiency in IL-36R antagonist caused by loss of function mutations in IL-36RN leads to DITRA (1), a rare inflammatory human disease that belongs to a subgroup of Generalized Pustular Psoriasis (GPP). Herein, we report a novel functional genetic mouse model of DITRA with enhanced IL-36R signaling analogous to one observed in DITRA patients which supports and provides new insight in our understanding of IL-36 family of molecules in regulating barrier integrity across multiple tissues. Humanized DITRA-like mice displayed increased skin inflammation in preclinical model of psoriasis, and in vivo blockade of IL-36R pathway using anti-human IL-36R antibody ameliorated IMQ-induced skin pathology at both prophylactic and therapeutic treatments. Deeper characterization of the humanized DITRA-like mice revealed that deregulated IL-36R signaling promoted tissue pathology during intestinal injury and led to impairment in mucosal restoration in the repair phase of chronic DSS-induced colitis. Blockade of IL-36R pathway significantly ameliorated DSS-induced intestinal inflammation and rescued the inability of DITRA-like mice to recover from mucosal damage in vivo. Thus, our results indicate a central role for IL-36 in regulating the pro-inflammatory responses in the skin and epithelial barrier function in the intestine suggesting a new therapeutic potential for IL-36R axis in psoriasis and at the later stages of intestinal pathology.