Protein oxidation of fucose environments (POFE) reveals fucose-protein interactions

Cell membrane glycoproteins are generally highly fucosylated and sialylated, and post-translational modifications play important roles in the proteins' functions of signaling, binding and cellular processing. For these reasons, methods for measuring sialic acid-mediated protein-protein interactions have been developed. However, determining the role of fucose in these interactions has been limited by technological barriers that have thus far hindered the ability to characterize and observe fucose-mediated protein-protein interactions. Herein, we describe a method to metabolically label mammalian cells with modified fucose, which incorporates a bioorthogonal group into cell membrane glycoproteins thereby enabling the characterization of cell-surface fucose interactome. Copper-catalyzed click chemistry was used to conjugate a proximity labeling probe, azido-FeBABE. Following the addition of hydrogen peroxide (H2O2), the fucose-azido-FeBABE catalyzed the formation of hydroxyl radicals, which in turn oxidized the amino acids in the proximity of the labeled fucose residue. The oxidized peptides were identified using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Variations in degree of protein oxidation were obtained with different H2O2 reaction times yielding the acquisition of spatial information of the fucose-interacting proteins. In addition, specific glycoprotein-protein interactions were constructed for Galectin-3 (LEG3) and Galectin-3-binding protein (LG3BP) illustrating the further utility of the method. This method identifies new fucose binding partners thereby enhancing our understanding of the cell glycocalyx.

Suppression of TCF4 promotes a ZC3H12A-mediated self-sustaining inflammatory feedback cycle involving IL-17RA/IL-17RE epidermal signaling

IL-17C is an epithelial cell-derived proinflammatory cytokine whose transcriptional regulation remains unclear. Analysis of the IL17C promoter region identified TCF4 as putative regulator, and siRNA knockdown of TCF4 in human keratinocytes (KCs) increased IL17C. IL-17C stimulation of KCs (along with IL-17A and TNF-α stimulation) decreased TCF4 and increased NFKBIZ and ZC3H12A expression in an IL-17RA/RE-dependent manner, thus creating a feedback loop. ZC3H12A (MCPIP1/Regnase-1), a transcriptional immune-response regulator, also increased following TCF4 siRNA knockdown, and siRNA knockdown of ZC3H12A decreased NFKBIZ, IL1B, IL36G, CCL20, and CXCL1, revealing a proinflammatory role for ZC3H12A. Examination of lesional skin from the KC-Tie2 inflammatory dermatitis mouse model identified decreases in TCF4 protein concomitant with increases in IL-17C and Zc3h12a that reversed following the genetic elimination of Il17c, Il17ra, and Il17re and improvement in the skin phenotype. Conversely, interference with Tcf4 in KC-Tie2 mouse skin increased Il17c and exacerbated the inflammatory skin phenotype. Together, these findings identify a role for TCF4 in the negative regulation of IL-17C, which, alone and with TNF-α and IL-17A, feed back to decrease TCF4 in an IL-17RA/RE-dependent manner. This loop is further amplified by IL-17C-TCF4 autocrine regulation of ZC3H12A and IL-17C regulation of NFKBIZ to promote self-sustaining skin inflammation.

Support Group Participation Among Patients With Alopecia Areata

This cross-sectional study describes support group use and experience among patients with alopecia areata.

Combined analysis of secreted proteins and glycosylation identifies prognostic features in cholangiocarcinoma

Secreted proteins are overexpressed in cholangiocarcinoma (CCA) and actively involved in promoting metastatic spread. Many of these proteins possess one or more sites of glycosylation and their various glycoforms have potential utility as prognostic or diagnostic biomarkers. To evaluate the effects of secretome glycosylation on patient outcome, we elucidated the glycosylation patterns of proteins secreted by parental and metastatic CCA cells using liquid chromatography-mass spectrometry. Our analysis showed that the secretome of CCA cells was dominated by fucosylated and fucosialylated glycoforms. Based on the glycan and protein profiles, we evaluated the combined prognostic significance of glycosyltransferases and secretory proteins. Significantly, genes encoding fucosyltransferases and sialyltransferases showed favorable prognostic effects when combined with secretory protein-coding gene expression, particularly thrombospondin-1. Combining these measures may provide improved risk assessment for CCA and be used to indicate stages of disease progression.

HERC6 regulates STING activity in a sex-biased manner through modulation of LATS2/VGLL3 Hippo signaling

Interferon (IFN) activity exhibits a gender bias in human skin, skewed toward females. We show that HERC6, an IFN-induced E3 ubiquitin ligase, is induced in human keratinocytes through the epidermal type I IFN; IFN-κ. HERC6 knockdown in human keratinocytes results in enhanced induction of interferon-stimulated genes (ISGs) upon treatment with a double-stranded (ds) DNA STING activator cGAMP but not in response to the RNA-sensing TLR3 agonist. Keratinocytes lacking HERC6 exhibit sustained STING-TBK1 signaling following cGAMP stimulation through modulation of LATS2 and TBK1 activity, unmasking more robust ISG responses in female keratinocytes. This enhanced female-biased immune response with loss of HERC6 depends on VGLL3, a regulator of type I IFN signature. These data identify HERC6 as a previously unrecognized negative regulator of ISG expression specific to dsDNA sensing and establish it as a regulator of female-biased immune responses through modulation of STING signaling.

Single-cell sequencing reveals Hippo signaling as a driver of fibrosis in hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by abscesses, nodules, dissecting/draining tunnels, and extensive fibrosis. Here, we integrate single-cell RNA sequencing, spatial transcriptomics, and immunostaining to provide an unprecedented view of the pathogenesis of chronic HS, characterizing the main cellular players and defining their interactions. We found a striking layering of the chronic HS infiltrate and identified the contribution of 2 fibroblast subtypes (SFRP4+ and CXCL13+) in orchestrating this compartmentalized immune response. We further demonstrated the central role of the Hippo pathway in promoting extensive fibrosis in HS and provided preclinical evidence that the profibrotic fibroblast response in HS can be modulated through inhibition of this pathway. These data provide insights into key aspects of HS pathogenesis with broad therapeutic implications.

IL-23 induces CLEC5A+ IL-17A+ neutrophils and elicit skin inflammation associated with psoriatic arthritis

IL-23-activation of IL-17 producing T cells is involved in many rheumatic diseases. Herein, we investigate the role of IL-23 in the activation of myeloid cell subsets that contribute to skin inflammation in mice and man. IL-23 gene transfer in WT, IL-23RGFP reporter mice and subsequent analysis with spectral cytometry show that IL-23 regulates early innate immune events by inducing the expansion of a myeloid MDL1+CD11b+Ly6G+ population that dictates epidermal hyperplasia, acanthosis, and parakeratosis; hallmark pathologic features of psoriasis. Genetic ablation of MDL-1, a major PU.1 transcriptional target during myeloid differentiation exclusively expressed in myeloid cells, completely prevents IL-23-pathology. Moreover, we show that IL-23-induced myeloid subsets are also capable of producing IL-17A and IL-23R+MDL1+ cells are present in the involved skin of psoriasis patients and gene expression correlations between IL-23 and MDL-1 have been validated in multiple patient cohorts. Collectively, our data demonstrate a novel role of IL-23 in MDL-1-myelopoiesis that is responsible for skin inflammation and related pathologies. Our data open a new avenue of investigations regarding the role of IL-23 in the activation of myeloid immunoreceptors and their role in autoimmunity.

Systems-based identification of the Hippo pathway for promoting fibrotic mesenchymal differentiation in systemic sclerosis

Systemic sclerosis (SSc) is a devastating autoimmune disease characterized by excessive production and accumulation of extracellular matrix, leading to fibrosis of skin and other internal organs. However, the main cellular participants in SSc skin fibrosis remain incompletely understood. Here using differentiation trajectories at a single cell level, we demonstrate a dual source of extracellular matrix deposition in SSc skin from both myofibroblasts and endothelial-to-mesenchymal-transitioning cells (EndoMT). We further define a central role of Hippo pathway effectors in differentiation and homeostasis of myofibroblast and EndoMT, respectively, and show that myofibroblasts and EndoMTs function as central communication hubs that drive key pro-fibrotic signaling pathways in SSc. Together, our data help characterize myofibroblast differentiation and EndoMT phenotypes in SSc skin, and hint that modulation of the Hippo pathway may contribute in reversing the pro-fibrotic phenotypes in myofibroblasts and EndoMTs.

Management of Adult Patients With Drug Reaction With Eosinophilia and Systemic Symptoms: A Delphi-Based International Consensus

Importance

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare but potentially fatal drug hypersensitivity reaction. To our knowledge, there is no international consensus on its severity assessment and treatment.

Objective

To reach an international, Delphi-based multinational expert consensus on the diagnostic workup, severity assessment, and treatment of patients with DRESS.

Design, Setting, and Participants

The Delphi method was used to assess 100 statements related to baseline workup, evaluation of severity, acute phase, and postacute management of DRESS. Fifty-seven international experts in DRESS were invited, and 54 participated in the survey, which took place from July to September 2022.

Main Outcomes/Measures

The degree of agreement was calculated with the RAND-UCLA Appropriateness Method. Consensus was defined as a statement with a median appropriateness value of 7 or higher (appropriate) and a disagreement index of lower than 1.

Results

In the first Delphi round, consensus was reached on 82 statements. Thirteen statements were revised and assessed in a second round. A consensus was reached for 93 statements overall. The experts agreed on a set of basic diagnostic workup procedures as well as severity- and organ-specific further investigations. They reached a consensus on severity assessment (mild, moderate, and severe) based on the extent of liver, kidney, and blood involvement and the damage of other organs. The panel agreed on the main lines of DRESS management according to these severity grades. General recommendations were generated on the postacute phase follow-up of patients with DRESS and the allergological workup.

Conclusions and Relevance

This Delphi exercise represents, to our knowledge, the first international expert consensus on diagnostic workup, severity assessment, and management of DRESS. This should support clinicians in the diagnosis and management of DRESS and constitute the basis for development of future guidelines.

Single-cell profiling of prurigo nodularis demonstrates immune-stromal crosstalk driving profibrotic responses and reversal with nemolizumab

BACKGROUND

Prurigo nodularis (PN) is a chronic neuroimmune skin disease characterized by bilaterally distributed pruritic hyperkeratotic nodules on extremities and trunk. Neuroimmune dysregulation and chronic scratching are believed to both induce and maintain the characteristic lesions.

OBJECTIVES

This study sought to provide a comprehensive view of the molecular pathogenesis of PN at the single-cell level to identify and outline key pathologic processes and the cell types involved. Features that distinguish PN skin from the skin of patients with atopic dermatitis were of particular interest. We further aimed to determine the impact of the IL31RA antagonist, nemolizumab, and its specificity at the single-cell level.

METHODS

Single-cell RNA-sequencing of skin from 15 healthy donors and nonlesional and lesional skin from 6 patients each with PN and atopic dermatitis, combined with spatial-sequencing using the 10x Visium platform. Integration with bulk RNA-sequencing data from patients treated with nemolizumab.

RESULTS

This study demonstrates that PN is an inflammatory skin disease characterized by both keratinocyte proliferation and activation of profibrotic responses. This study also demonstrates that the COL11A1+ fibroblast subset is a major contributor to fibrosis and is predominantly found in the papillary dermis of PN skin. Activation of fibrotic responses is the main distinguishing feature between PN and atopic dermatitis skin. This study further shows the broad effect of nemolizumab on PN cell types, with a prominent effect driving COL11A1+ fibroblast and keratinocyte responses toward normal.

CONCLUSIONS

This study provides a high-resolution characterization of the cell types and cellular processes activated in PN skin, establishing PN as a chronic fibrotic inflammatory skin disease. It further demonstrates the broad effect of nemolizumab on pathological processes in PN skin.

Rituximab and Omalizumab Combination Therapy for Bullous Pemphigoid

This research letter reports on a case series of 10 patients with bullous pemphigoid treated with rituximab combined with omalizumab.

Maintaining and Restoring Gradients of Ions in the Epidermis: The Role of Ion and Water Channels in Acute Cutaneous Wound Healing

Significance: Aquaporins and ion channels establish and regulate gradients of calcium, sodium, potassium, chloride, water, and protons in the epidermis. These elements have been found to play significant roles in skin biology and wound healing. In this study, we review our understanding of these channels and ion gradients, with a special emphasis on their role in acute wound healing. Recent Advances: Specifically, we assess the temporal and spatial arrangements of ions and their respective channels in the intact skin and during wound and healing to provide a novel perspective of the role of ionic gradients through the various stages of wound healing. Critical Issues: The roles of gradients of ions and channels in wound healing are currently not well understood. A collective analysis of their traits and arrangements in the skin during wound healing may provide a new perspective and understanding of the functionality of gradients of ions and channels in skin biology and wound healing. Future Directions: It is important to elucidate how the gradients of ions and ion channels regulate and facilitate wound healing. A better understanding of the ionic environments may identify novel therapeutic targets and improved strategies to promote wound healing and possibly treat other cutaneous diseases.

Janus kinase inhibitors for alopecia areata: A narrative review

The Janus kinase (JAK) and Signal Transducer and Activator of Transcription (STAT) pathway has been identified as a key player in the pathophysiology of alopecia areata and a potential target for therapy. Here, we give a narrative review of what is known about Janus kinase inhibitors in alopecia areata. Several clinical trials as well as smaller studies have demonstrated hair regrowth and remission with oral Janus kinase inhibitors therapy, even in patients who failed conventional treatment. Baricitinib is the only US FDA-approved treatment for alopecia areata but data for other oral Janus kinase inhibitors such as tofacitinib, ruxolitinib and ritlecitinib are also promising. Fewer clinical trials have investigated topical Janus kinase inhibitors for alopecia areata, with many of them terminated early due to unfavourable results. Overall, Janus kinase inhibitors are an efficacious addition to the therapeutic arsenal for treatment-refractory alopecia areata. Further work is needed to examine the effects of long-term usage of Janus kinase inhibitors, the efficacy of topical Janus kinase inhibitors, as well as to identify biomarkers that could predict differential therapeutic responses to the various Janus kinase inhibitors.

Virally encoded interleukin-6 facilitates KSHV replication in monocytes and induction of dysfunctional macrophages

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic double-stranded DNA virus and the etiologic agent of Kaposi's sarcoma and hyperinflammatory lymphoproliferative disorders. Understanding the mechanism by which KSHV increases the infected cell population is crucial for curing KSHV-associated diseases. Using scRNA-seq, we demonstrate that KSHV preferentially infects CD14+ monocytes, sustains viral lytic replication through the viral interleukin-6 (vIL-6), which activates STAT1 and 3, and induces an inflammatory gene expression program. To study the role of vIL-6 in monocytes upon KSHV infection, we generated recombinant KSHV with premature stop codon (vIL-6(-)) and its revertant viruses (vIL-6(+)). Infection of the recombinant viruses shows that both vIL-6(+) and vIL-6(-) KSHV infection induced indistinguishable host anti-viral response with STAT1 and 3 activations in monocytes; however, vIL-6(+), but not vIL-6(-), KSHV infection promoted the proliferation and differentiation of KSHV-infected monocytes into macrophages. The macrophages derived from vIL-6(+) KSHV infection showed a distinct transcriptional profile of elevated IFN-pathway activation with immune suppression and were compromised in T-cell stimulation function compared to those from vIL-6(-) KSHV infection or uninfected control. Notably, a viral nuclear long noncoding RNA (PAN RNA), which is required for sustaining KSHV gene expression, was substantially reduced in infected primary monocytes upon vIL-6(-) KSHV infection. These results highlight the critical role of vIL-6 in sustaining KSHV transcription in primary monocytes. Our findings also imply a clever strategy in which KSHV utilizes vIL-6 to secure its viral pool by expanding infected monocytes via differentiating into longer-lived dysfunctional macrophages. This mechanism may facilitate KSHV to escape from host immune surveillance and to support a lifelong infection.

A qualitative exploration of patient experiences in pyoderma gangrenosum

Pyoderma gangrenosum (PG) is a rare neutrophilic dermatosis that is associated with a decreased quality-of-life (QoL). There are no PG-specific patient-reported outcome measures. In this exploratory study, we use patient interviews to define QoL domains in PG that will inform future outcomes measures.

Atezolizumab plus stereotactic ablative radiotherapy for medically inoperable patients with early-stage non-small cell lung cancer: a multi-institutional phase I trial

Stereotactic ablative radiotherapy (SABR) is a standard-of-care for medically-inoperable-early-stage non-small cell lung cancer (NSCLC). One third of patients progress and chemotherapy is rarely used in this population. We questioned if addition of the immune-checkpoint-inhibitor (ICI) atezolizumab to standard-of-care SABR can improve outcomes. We initiated a multi-institutional single-arm phase I study (NCT02599454) enrolling twenty patients with the primary endpoint of maximum tolerated dose (MTD); secondary endpoints of safety and efficacy; and exploratory mechanistic correlatives. Treatment is well tolerated and full dose atezolizumab (1200 mg) is the MTD. Efficacy signals include early responses (after 2 cycles of ICI, before initiation of SABR) in 17% of patients. Biomarkers of functional adaptive immunity, including T cell activation in the tumor and response to ex-vivo stimulation by circulating T cells, are highly predictive of benefit. These results require validation and are being tested in a phase III randomized trial.

Interleukin-23 Regulates Inflammatory Osteoclastogenesis via Activation of CLEC5A(+) Osteoclast Precursors

OBJECTIVE

To investigate the role of interleukin-23 (IL-23) in pathologic bone remodeling in inflammatory arthritis.

METHODS

In this study we investigated the role of IL-23 in osteoclast differentiation and activation using in vivo gene transfer techniques in wild-type and myeloid DNAX-activation protein 12-associating lectin-1 (MDL-1)-deficient mice, and by performing in vitro and in vivo osteoclastogenesis assays using spectral flow cytometry, micro-computed tomography analysis, Western blotting, and immunoprecipitation.

RESULTS

Herein, we show that IL-23 induces the expansion of a myeloid osteoclast precursor population and supports osteoclastogenesis and bone resorption in inflammatory arthritis. Genetic ablation of C-type lectin domain family member 5A, also known as MDL-1, prevents the induction of osteoclast precursors by IL-23 that is associated with bone destruction, as commonly observed in inflammatory arthritis. Moreover, osteoclasts derived from the bone marrow of MDL-1-deficient mice showed impaired osteoclastogenesis, and MDL-1-/- mice had increased bone mineral density.

CONCLUSION

Our data show that IL-23 signaling regulates the availability of osteoclast precursors in inflammatory arthritis that could be effectively targeted for the treatment of inflammatory bone loss in inflammatory arthritis.

Intravenous immunoglobulin is safe and effective in controlling pre-existing paraneoplastic neuromuscular diseases in cancer patients treated with immune checkpoint inhibitors: two case reports and literature review

Immune checkpoint inhibitors cause rare but potentially fatal neuromuscular complications, leading to a concern to use these agents in cancer patients with pre-existing autoimmune or inflammatory neuromuscular diseases. We report two such patients with paraneoplastic dermatomyositis and "seronegative" paraneoplastic demyelinating neuropathy, respectively, who have been successfully treated with immune checkpoint inhibitor monotherapy as well as maintenance intravenous immunoglobulin. While controlling the paraneoplastic or autoimmune neuromuscular diseases, the use of intravenous immunoglobulin did not compromise the anti-cancer effect of immune checkpoint inhibitor.

Cell-Specific and Variant-Linked Alterations in Expression of ERAP1, ERAP2, and LNPEP Aminopeptidases in Psoriasis

ERAP1, ERAP2, and LNPEP are aminopeptidases implicated in autoimmune pathophysiology. In this study, we show that ERAP2 is upregulated and ERAP1 is downregulated in patients with psoriasis who are homozygous for autoimmune-linked variants of ERAP. We also demonstrate that aminopeptidase expression is not uniform in the skin. Specifically, the intracellular antigen-processing aminopeptidases ERAP1 and ERAP2 are strongly expressed in basal and early spinous layer keratinocytes, whereas granular layer keratinocytes expressed predominantly LNPEP, an aminopeptidase specialized in the processing of extracellular antigens for presentation to T cells. In psoriasis, basal keratinocytes also expressed the T-cell- and monocyte-attracting chemokine, CCL2, and the T-cell-supporting cytokine, IL-15. In contrast, TGF-β1 was the major cytokine expressed by healthy control basal keratinocytes. SFRP2-high dermal fibroblasts were also noted to have an ERAP2-high expression phenotype and elevated HLA-C. In psoriasis, the SFRP2-high fibroblast subpopulation also expressed elevated CXCL14. From these results, we postulate that (i) an increased ERAP2/ERAP1 ratio results in altered antigen processing, a potential mechanism by which ERAP risk alleles predispose individuals to autoimmunity; (ii) ERAP2-high expressing cells display a unique major histocompatibility complex-bound peptidome generated from intracellular antigens; and (iii) the granular layer peptidome is skewed toward extracellular antigens.

Development of a Skin-Directed Scoring System for Stevens-Johnson Syndrome and Epidermal Necrolysis: A Delphi Consensus Exercise

Importance

Scoring systems for Stevens-Johnson syndrome and epidermal necrolysis (EN) only estimate patient prognosis and are weighted toward comorbidities and systemic features; morphologic terminology for EN lesions is inconsistent.

Objectives

To establish consensus among expert dermatologists on EN terminology, morphologic progression, and most-affected sites, and to build a framework for developing a skin-directed scoring system for EN.

Evidence Review

A Delphi consensus using the RAND/UCLA appropriateness criteria was initiated with a core group from the Society of Dermatology Hospitalists to establish agreement on the optimal design for an EN cutaneous scoring instrument, terminology, morphologic traits, and sites of involvement.

Findings

In round 1, the 54 participating dermatology hospitalists reached consensus on all 49 statements (30 appropriate, 3 inappropriate, 16 uncertain). In round 2, they agreed on another 15 statements (8 appropriate, 7 uncertain). There was consistent agreement on the need for a skin-specific instrument; on the most-often affected skin sites (head and neck, chest, upper back, ocular mucosa, oral mucosa); and that blanching erythema, dusky erythema, targetoid erythema, vesicles/bullae, desquamation, and erosions comprise the morphologic traits of EN and can be consistently differentiated.

Conclusions and Relevance

This consensus exercise confirmed the need for an EN skin-directed scoring system, nomenclature, and differentiation of specific morphologic traits, and identified the sites most affected. It also established a baseline consensus for a standardized EN instrument with consistent terminology.

Single cell and spatial sequencing define processes by which keratinocytes and fibroblasts amplify inflammatory responses in psoriasis

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 occur 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 in-depth view of psoriasis pathogenesis, which expands our understanding of the critical cellular participants to include inflammatory fibroblasts and their cellular interactions.

S2k guidelines on the management of paraneoplastic pemphigus/paraneoplastic autoimmune multiorgan syndrome initiated by the European Academy of Dermatology and Venereology (EADV)

BACKGROUND

Paraneoplastic pemphigus (PNP), also called paraneoplastic autoimmune multiorgan syndrome (PAMS), is a rare autoimmune disease with mucocutaneous and multi-organ involvement. PNP/PAMS is typically associated with lymphoproliferative or haematological malignancies, and less frequently with solid malignancies. The mortality rate of PNP/PAMS is elevated owing to the increased risk of severe infections and disease-associated complications, such as bronchiolitis obliterans.

OBJECTIVES

These guidelines summarize evidence-based and expert-based recommendations (S2k level) for the clinical characterization, diagnosis and management of PNP/PAMS. They have been initiated by the Task Force Autoimmune Blistering Diseases of the European Academy of Dermatology and Venereology with the contribution of physicians from all relevant disciplines. The degree of consent among all task force members was included.

RESULTS

Chronic severe mucositis and polymorphic skin lesions are clue clinical characteristics of PNP/PAMS. A complete assessment of the patient with suspected PNP/PAMS, requiring histopathological study and immunopathological investigations, including direct and indirect immunofluorescence, ELISA and, where available, immunoblotting/immunoprecipitation, is recommended to achieve a diagnosis of PNP/PAMS. Detection of anti-envoplakin antibodies and/or circulating antibodies binding to the rat bladder epithelium at indirect immunofluorescence is the most specific tool for the diagnosis of PNP/PAMS in a patient with compatible clinical and anamnestic features. Treatment of PNP/PAMS is highly challenging. Systemic steroids up to 1.5 mg/kg/day are recommended as first-line option. Rituximab is also recommended in patients with PNP/PAMS secondary to lymphoproliferative conditions but might also be considered in cases of PNP/PAMS associated with solid tumours. A multidisciplinary approach involving pneumologists, ophthalmologists and onco-haematologists is recommended for optimal management of the patients.

CONCLUSIONS

These are the first European guidelines for the diagnosis and management of PNP/PAMS. Diagnostic criteria and therapeutic recommendations will require further validation by prospective studies.

IL-27 attenuates IL-23 mediated inflammatory arthritis

Interleukin 27 has both pro-inflammatory and anti-inflammatory properties in autoimmunity. The anti-inflammatory effects of IL-27 are linked with inhibition of Th17 differentiation but the IL-27 effect on myeloid cells is less studied. Herein we demonstrate that IL-27 inhibits IL-23-induced inflammation associated not only with Th17 cells but also with myeloid cell infiltration in the joints and splenic myeloid populations of CD11b⁺ GR1⁺ and CD3^-CD11b⁺CD11c^-GR1^- cells. The IL-27 anti-inflammatory response was associated with reduced levels of myeloid cells in the spleen and bone marrow. Overall, our data demonstrate that IL-27 has an immunosuppressive role that affects IL-23-dependent myelopoiesis in the bone marrow and its progression to inflammatory arthritis and plays a crucial role in controlling IL-23 driven joint inflammation by negatively regulating the expansion of myeloid cell subsets.

A review of topical probiotic therapy for atopic dermatitis

Atopic dermatitis (AD) is a common, chronic skin disorder that is associated with dysbiosis of the skin microbiome along with an impaired skin barrier and abnormal immune signalling. Particularly, AD has been associated with increased abundance of Staphylococcus aureus and decreased overall bacterial diversity. Topical probiotic formulations are garnering further interest in the treatment of AD and may be derived from commensal bacteria found on healthy epithelium or from exogenous bacteria. Strains chosen for clinical trials have often demonstrated antimicrobial actions to S. aureus in vitro. Multiple randomized clinical trials with topical probiotics have resulted in significant improvements in clinical severity, decreased abundance of S. aureus in treated lesional skin and increased bacterial diversity. Side-effects from available studies have been minimal apart from one patient who developed a furuncle in the treatment area. Topical probiotics have been shown to be safe and potentially efficacious in AD; however, further research including larger, longer-term clinical trials need to be performed before topical probiotics should be recommended to patients.

Efficacy and Safety of Risankizumab for the Treatment of Hidradenitis Suppurativa: A Phase 2, Randomized, Placebo-Controlled Trial

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, immune-mediated skin condition characterized by inflammatory lesions that can cause pain, impaired physical activity, and reduced quality of life. This study evaluated the efficacy and safety of risankizumab, a humanized immunoglobulin G1 monoclonal antibody that specifically inhibits interleukin 23 by binding to its p19 subunit, for the treatment of HS.

METHODS

This phase II multicenter, randomized, placebo-controlled, double-blind study investigated the efficacy and safety of risankizumab in patients with moderate-to-severe HS. Patients were randomized 1:1:1 to receive subcutaneous risankizumab 180 mg; risankizumab 360 mg; or placebo at weeks 0, 1, 2, 4, and 12. Patients initially randomized to placebo received blinded risankizumab 360 mg at weeks 16, 17, and 18; patients initially randomized to risankizumab received blinded matching placebo at the same time points. From weeks 20-60, all patients received open-label risankizumab 360 mg every 8 weeks. The primary endpoint was the achievement of HS Clinical Response (HiSCR) at week 16. Safety was assessed by monitoring of treatment-emergent adverse events (TEAEs).

RESULTS

A total of 243 patients were randomized (risankizumab 180 mg, n = 80; risankizumab 360 mg, n = 81; placebo, n = 82). HiSCR was achieved by 46.8% of patients with risankizumab 180 mg, 43.4% with risankizumab 360 mg, and 41.5% with placebo at week 16. The primary endpoint was not met, and the study was terminated early. Incidence of TEAEs, severe TEAEs, TEAEs considered possibly related to study drug, and TEAEs leading to discontinuation of study drug were generally low and comparable across treatment groups.

CONCLUSION

Risankizumab does not appear to be an efficacious treatment for moderate-to-severe HS. Future studies to understand the complex molecular mechanisms underlying HS pathogenesis and develop improved therapies are warranted.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03926169.

KSHV uses viral IL6 to expand infected immunosuppressive macrophages

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic double-stranded DNA virus and the etiologic agent of Kaposi's sarcoma and hyperinflammatory lymphoproliferative disorders. Understanding the mechanism by which KSHV increases the infected cell population is crucial for curing KSHV-associated diseases. Here we demonstrate that KSHV preferentially infects CD14 ⁺ monocytes and sustains viral replication through the viral (v)IL6-mediated activation of STAT1 and 3. Using vIL6-sufficient and vIL6-deficient recombinant KSHV, we demonstrated that vIL6 plays a critical role in promoting the proliferation and differentiation of KSHV-infected monocytes into macrophages. Those macrophages from vIL6-sufficient (wild type) KSHV infection showed a distinct transcriptional profile of elevated IFN-pathway activation with immune suppression and were compromised in T-cell stimulation function compared to those from vIL6-deficient KSHV infection or uninfected control. These results highlight a clever strategy, in which KSHV utilizes vIL6 to secure its initial viral pool by expanding infected dysfunctional macrophages. This mechanism also facilitates KSHV to escape from host immune surveillance to establish a lifelong infection.

Summary

KSHV causes multiple inflammatory diseases, however, the mechanism is not clear. Shimoda et al. demonstrate that KSHV preferentially infects monocytes and utilizes virally encoded IL6 to expand and deregulate infected monocytes. This helps the virus escape from host immune surveillance.

Post-acute phase and sequelae management of epidermal necrolysis: an international, multidisciplinary DELPHI-based consensus

BACKGROUND

Long-term sequelae are frequent and often disabling after epidermal necrolysis (Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)). However, consensus on the modalities of management of these sequelae is lacking.

OBJECTIVES

We conducted an international multicentric DELPHI exercise to establish a multidisciplinary expert consensus to standardize recommendations regarding management of SJS/TEN sequelae.

METHODS

Participants were sent a survey via the online tool "Survey Monkey" consisting of 54 statements organized into 8 topics: general recommendations, professionals involved, skin, oral mucosa and teeth, eyes, genital area, mental health, and allergy workup. Participants evaluated the level of appropriateness of each statement on a scale of 1 (extremely inappropriate) to 9 (extremely appropriate). Results were analyzed according to the RAND/UCLA Appropriateness Method.

RESULTS

Fifty-two healthcare professionals participated. After the first round, a consensus was obtained for 100% of 54 initially proposed statements (disagreement index < 1). Among them, 50 statements were agreed upon as 'appropriate'; four statements were considered 'uncertain', and ultimately finally discarded.

CONCLUSIONS

Our DELPHI-based expert consensus should help guide physicians in conducting a prolonged multidisciplinary follow-up of sequelae in SJS-TEN.

Differential cell composition and split epidermal differentiation in human palm, sole, and hip skin

Palmoplantar skin is structurally and functionally unique, but the transcriptional programs driving this specialization are unclear. Here, we use bulk and single-cell RNA sequencing of human palm, sole, and hip skin to describe the distinguishing characteristics of palmoplantar and non-palmoplantar skin while also uncovering differences between palmar and plantar sites. Our approach reveals an altered immune environment in palmoplantar skin, with downregulation of diverse immunological processes and decreased immune cell populations. Further, we identify specific fibroblast populations that appear to orchestrate key differences in cell-cell communication in palm, sole, and hip. Dedicated keratinocyte analysis highlights major differences in basal cell fraction among the three sites and demonstrates the existence of two spinous keratinocyte populations constituting parallel, site-selective epidermal differentiation trajectories. In summary, this deep characterization of highly adapted palmoplantar skin contributes key insights into the fundamental biology of human skin and provides a valuable data resource for further investigation.

Melanoma in women of childbearing age and in pregnancy in California, 1994-2015: a population-based cohort study

BACKGROUND

Melanoma is one of the most common malignancies during pregnancy. There is debate regarding the impact of pregnancy on the prognosis of melanoma. Recent large population-based studies from the United States are lacking.

OBJECTIVES

To determine the characteristics and survival of women with pregnancy-associated melanoma.

METHODS

This population-based, retrospective cohort study used California Cancer Registry data linked with state-wide hospitalization and ambulatory surgery data to identify 15-44-year-old female patients diagnosed with melanoma in 1994-2015, including pregnant patients. Multivariable logistic regression compared demographic and clinical characteristics between pregnant and non-pregnant women with melanoma. Multivariable cox proportional hazards regression models assessed melanoma-specific and overall survival.

RESULTS

We identified 13 108 patients, of which 1406 were pregnant. Pregnancy-associated melanoma was more frequent in Hispanic compared to non-Hispanic White women. Melanoma occurring post-partum was associated with greater tumour thickness (2.01-4.00 vs. 0.01-1.00 mm, odds ratio 1.75, 95% confidence interval: 1.03-2.98). There were otherwise no significant differences between pregnant and non-pregnant women. Worse survival was associated with Asian, Black and Native American race/ethnicity (vs. non-Hispanic White), lower neighbourhood socio-economic status, public insurance, tumour site, greater tumour thickness and lymph node involvement, but not pregnancy.

CONCLUSIONS

Melanoma occurring post-partum was associated with greater tumour thickness, but pregnancy status did not affect survival after melanoma. Race/ethnicity, socio-economic status and health insurance impacted survival, emphasizing the importance of reducing health disparities.

Peripheral γδ T Cells Regulate Neutrophil Expansion and Recruitment in Experimental Psoriatic Arthritis

OBJECTIVE

This study was undertaken to identify the mechanistic role of γδ T cells in the pathogenesis of experimental psoriatic arthritis (PsA).

METHODS

In this study, we performed interleukin-23 (IL-23) gene transfer in wild-type (WT) and T cell receptor δ-deficient (TCRδ-/- ) mice and conducted tissue phenotyping in the joint, skin, and nails to characterize the inflammatory infiltrate. We further performed detailed flow cytometry, immunofluorescence staining, RNA sequencing, T cell repertoire analysis, and in vitro T cell polarization assays to identify regulatory mechanisms of γδ T cells.

RESULTS

We demonstrated that γδ T cells support systemic granulopoiesis, which is critical for murine PsA-like pathology. Briefly, γδ T cell ablation inhibited the expression of neutrophil chemokines CXCL1 and CXCL2 and neutrophil CD11b+Ly6G+ accumulation in the aforementioned PsA-related tissues. Although significantly reduced expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-17A was detected systemically in TCRδ-/- mice, no GM-CSF+/IL-17A+ γδ T cells were detected locally in the inflamed skin or bone marrow in WT mice. Our data showed that nonresident γδ T cells regulate the expansion of an CD11b+Ly6G+ neutrophil population and their recruitment to joint and skin tissues, where they develop hallmark pathologic features of human PsA.

CONCLUSION

Our findings do not support the notion that tissue-resident γδ T cells initiate the disease but demonstrate a novel role of γδ T cells in neutrophil regulation that can be exploited therapeutically in PsA patients.

Biogeographic and disease-specific alterations in epidermal lipid composition and single cell analysis of acral keratinocytes

The epidermis is the outermost layer of skin. Here, we used targeted lipid profiling to characterize the biogeographic alterations of human epidermal lipids across 12 anatomically distinct body sites, and we used single-cell RNA-Seq to compare keratinocyte gene expression at acral and nonacral sites. We demonstrate that acral skin has low expression of EOS acyl-ceramides and the genes involved in their synthesis, as well as low expression of genes involved in filaggrin and keratin citrullination (PADI1 and PADI3) and corneodesmosome degradation, changes that are consistent with increased corneocyte retention. Several overarching principles governing epidermal lipid expression were also noted. For example, there was a strong negative correlation between the expression of 18-carbon and 22-carbon sphingoid base ceramides. Disease-specific alterations in epidermal lipid gene expression and their corresponding alterations to the epidermal lipidome were characterized. Lipid biomarkers with diagnostic utility for inflammatory and precancerous conditions were identified, and a 2-analyte diagnostic model of psoriasis was constructed using a step-forward algorithm. Finally, gene coexpression analysis revealed a strong connection between lipid and immune gene expression. This work highlights (a) mechanisms by which the epidermis is uniquely adapted for the specific environmental insults encountered at different body surfaces and (b) how inflammation-associated alterations in gene expression affect the epidermal lipidome.

Demographic and Clinical Factors Associated with Patient-Reported Remission in Psoriatic Arthritis

Introduction

Achievement of remission in psoriatic arthritis is a key goal for patients and clinicians, yet definitions of remission may vary. Previous efforts have utilized multidomain measures such as minimal disease activity that assess the status of joints, skin, and function to determine current level of psoriatic arthritis (PsA) disease activity. The goal of this study is to identify factors associated with patient-reported psoriatic arthritis remission.

Methods

The National Psoriasis Foundation conducted a cross-sectional study using an online survey of a random stratified sample of 1570 individuals with psoriatic disease in the USA. Participants were asked about a provider diagnosis of psoriasis and/or psoriatic arthritis, comorbid conditions, and psoriatic arthritis impact and disease activity, and demographic questions. All participants reporting a physician-given diagnosis of psoriatic arthritis were asked if they felt their psoriatic arthritis was in remission (“Do you feel your psoriatic arthritis is in remission?” Yes/No/Unsure) and, if so, length of remission. Individuals with psoriasis and psoriatic arthritis reporting a body surface area impacted by psoriasis 3% or less were asked if they felt their psoriasis was in remission. Psoriatic arthritis disease activity and impact was assessed using the nine-question Psoriatic Arthritis Impact of Disease (PsAID-9) instrument and a global PsA-related quality of life question. PsAID-9 scores ≤ 4 were used to indicate acceptable disease state. Multivariate logistic regression was used to identify factors associated with patient-perceived PsA remission.

Results

Of 834 participants with PsA, including 76 (4.8%) with PsA without skin involvement ever, 144 (17.3%) felt their psoriatic arthritis was in remission, with an average remission duration of 43 months. Of those in remission, 116 (78.4%) reported currently using a treatment for their PsA, with most (75.7%) reporting using a biologic therapy for their PsA in the past 12 months. Multivariate logistic regression revealed that patient-perceived psoriatic arthritis remission was independently associated with experiencing acceptable disease state (PsAID-9 ≤ 4), perception of psoriasis remission, lower impact of PsA on global quality of life, and non-white race. Age, sex, body mass index, or biologic use in the last 12 months were not associated with patient-reported PsA remission.

Conclusion

Overall, patient perception of PsA remission was most strongly associated with patient-reported psoriasis remission.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a psoriasis susceptibility locus that is negatively related to IL36G

Proprotein convertase subtilisin/kexin type-9 (PCSK9) is a posttranslational regulator of the LDL receptor (LDLR). Recent studies have proposed a role for PCSK9 in regulating immune responses. Using RNA-Seq–based variant discovery, we identified a possible psoriasis-susceptibility locus at 1p32.3, located within PCSK9 (rs662145 C > T). This finding was verified in independently acquired genomic and RNA-Seq data sets. Single-cell RNA-Seq (scRNA-Seq) identified keratinocytes as the primary source of PCSK9 in human skin. PCSK9 expression, however, was not uniform across keratinocyte subpopulations. scRNA-Seq and IHC demonstrated an epidermal gradient of PCSK9, with expression being highest in basal and early spinous layer keratinocytes and lowest in granular layer keratinocytes. IL36G expression followed the opposite pattern, with expression highest in granular layer keratinocytes. PCSK9 siRNA knockdown experiments confirmed this inverse relationship between PCSK9 and IL36G expression. Other immune genes were also linked to PCSK9 expression, including IL27RA, IL1RL1, ISG20, and STX3. In both cultured keratinocytes and nonlesional human skin, homozygosity for PCSK9 SNP rs662145 C > T was associated with lower PCSK9 expression and higher IL36G expression, when compared with heterozygous skin or cell lines. Together, these results support PCSK9 as a psoriasis-susceptibility locus and establish a putative link between PCSK9 and inflammatory cytokine expression.

Serine and arginine rich splicing factor 1 deficiency alters pathways involved in IL-17A expression and is implicated in human psoriasis

Serine and Arginine Rich Splicing Factor 1 (SRSF1) is a splicing factor that binds to exonic enhancers and stimulates splicing and is previously implicated with autoimmunity. Herein, we investigate the role of SRSF1 in regulating innate immune functions that are pertinent in the pathogenesis of auto-inflammatory diseases. Specifically, we show that conditional deletion of SRSF1 in mature lymphocytes resulted in higher expression of il-17a and il-17 f and an expansion of IL17A+ CD8 T cells. Mechanistically, the aberrant expression of IL-17A in SRSF1 cKO mice could not be attributed to alternative splicing of il-17a or il-17 f genes but possibly to defective CD11B+LY6C+ myeloid derived suppressor function in the spleen. Finally, meta-analysis of RNA-Seq collected from psoriasis patients demonstrate a clear correlation between SRSF1 and psoriasis that suggests a putative role of SRSF1 in IL-17A-induced psoriasis.

Red Light Phototherapy Using Light-Emitting Diodes Inhibits Melanoma Proliferation and Alters Tumor Microenvironments

Background

Total annual cancer rates have decreased due to improved treatment and prevention. However, the incidence of melanoma is rising, and not all patients respond to immune and targeted approaches. Therefore, we sought to determine the efficacy of red light (RL) phototherapy in preclinical models of melanoma.

Methods

Melanoma cells (A375, B16F10, MNT-1) were irradiated with RL. Melanoma proliferation, apoptosis, oxidative stress, and p53 phosphorylation were measured in vitro. In C57BL/6 mice, phototherapy safety, B16F10 tumor growth, and immunocyte infiltration were assessed following RL.

Results

In vitro, 640 J/cm² RL decreased cellular proliferation without increasing apoptosis, while 1280 J/cm² increased apoptosis. RL increased intracellular reactive oxygen species generation and p53 phosphorylation. In animal models, 2560 J/cm² RL significantly prevented melanoma growth and increased the expression of CD103+ dendritic cells. 1280 and 1920 J/cm² RL decreased tumor volume, but not significantly. RL did not cause skin inflammation or erythema in normal skin.

Conclusion

RL represents a potentially safe and effective melanoma therapeutic. RL prevented tumor growth and increased the expression of immune markers, such as CD103, that are associated with favorable melanoma outcomes. Further research is needed to determine the optimal clinical treatment regimen for melanoma using RL.

Quantitative glycoproteomics of high-density lipoproteins

In this work, we developed a targeted glycoproteomic method to monitor the site-specific glycoprofiles and quantities of the most abundant HDL-associated proteins using Orbitrap LC-MS for (glyco)peptide target discovery and QqQ LC-MS for quantitative analysis. We conducted a pilot study using the workflow to determine whether HDL protein glycoprofiles are altered in healthy human participants in response to dietary glycan supplementation.

Noninvasive Tape-Stripping with High-Resolution RNA Profiling Effectively Captures a Preinflammatory State in Nonlesional Psoriatic Skin

Tape stripping is a minimally invasive, nonscarring method that can be utilized to assess gene expression in the skin but is infrequently used given technical constraints. By comparing different tape stripping technologies and full-thickness skin biopsy results of lesional and nonlesional psoriatic skin from the same patients, we demonstrate that tape stripping with optimized high-resolution transcriptomic profiling can be used to effectively assess and characterize inflammatory responses in the skin. Upon comparison with single-cell RNA-sequencing data from psoriatic full-thickness skin biopsies, we illustrate that tape-stripping efficiently captures the transcriptome of the upper layers of the epidermis with sufficient resolution to assess the molecular components of the feed-forward immune amplification pathway in psoriasis. Notably, nonlesional psoriatic skin sampled by tape stripping demonstrates activated, proinflammatory changes when compared to healthy control skin, suggesting a prepsoriatic state, which is not captured on full-thickness skin biopsy transcriptome profiling. This work illustrates an approach to assess inflammatory response in the epidermis by combining noninvasive sampling with high throughput RNA-sequencing, providing a foundation for biomarker discoveries and mechanism of action studies for inflammatory skin conditions.