Plasmacytoid Dendritic Cells Are Not Major Producers of Type 1 IFN in Cutaneous Lupus: An In-Depth Immunoprofile of Subacute and Discoid Lupus.

The immunologic drivers of cutaneous lupus erythematosus (CLE) and its clinical subtypes remain poorly understood. We sought to characterize the immune landscape of discoid lupus erythematosus and subacute CLE using multiplexed immunophenotyping. We found no significant differences in immune cell percentages between discoid lupus erythematosus and subacute CLE (P > .05) with the exception of an increase in TBK1 in discoid lupus erythematosus (P < .05). Unbiased clustering grouped subjects into 2 major clusters without respect to clinical subtype. Subjects with a history of smoking had increased percentages of neutrophils, disease activity, and endothelial granzyme B compared with nonsmokers. Despite previous assumptions, plasmacytoid dendritic cells (pDCs) did not stain for IFN-1. Skin-eluted and circulating pDCs from subjects with CLE expressed significantly less IFNα than healthy control pDCs upon toll-like receptor 7 stimulation ex vivo (P < .0001). These data suggest that discoid lupus erythematosus and subacute CLE have similar immune microenvironments in a multiplexed investigation. Our aggregated analysis of CLE revealed that smoking may modulate disease activity in CLE through neutrophils and endothelial granzyme B. Notably, our data suggest that pDCs are not the major producers of IFN-1 in CLE. Future in vitro studies to investigate the role of pDCs in CLE are needed.

Herbal supplement Spirulina stimulates inflammatory cytokine production in patients with dermatomyositis in vitro.

Spirulina, an herbal supplement and popular ingredient in health foods, is a potent stimulant of the immune system. Spirulina use is temporally associated with the onset or exacerbation of Dermatomyositis (DM), an autoimmune connective tissue disease that frequently affects the skin and muscle. In this study, we investigated the effect of Spirulina on peripheral blood mononuclear cells (PBMCs) in DM and Healthy Controls (HCs), showing that Spirulina stimulates Interferon ß (IFNß), Tumor necrosis factor α (TNFα), and Interferon γ (IFNγ) production of DM PBMCs primarily via Toll-Like Receptor 4 (TLR4) activation using ELISA (enzyme linked immunosorbent assay) and flow cytometry. We show that classical monocytes and monocyte-derived dendritic cells are stimulated by Spirulina and are activated via TLR4. Skin from patients with Spirulina-associated DM exhibits an inflammatory milieu similar to that of idiopathic DM but with a stronger correlation of TLR4 and IFNγ.

Particulate antigens administrated by intranasal and intravaginal routes in a prime-boost strategy improve HIV-specific TFH generation, high-quality antibodies and long-lasting mucosal immunity.

Mucosal surfaces serve as the primary entry points for pathogens such as SARS- CoV-2 coronavirus or HIV in the human body. Mucosal vaccination plays a crucial role to successfully induce long-lasting systemic and local immune responses to confer sterilizing immunity. However, antigen formulations and delivery methods must be properly selected since they are decisive for the quality and the magnitude of the elicited immune responses in mucosa. We investigated the significance of using particulate antigen forms for mucosal vaccination by comparing VLP- or protein- based vaccines in a mouse model. Based on a mucosal prime-boost immunization protocol combining (i) HIV- pseudotyped recombinant VLPs (HIV-VLPs) and (ii) plasmid DNA encoding HIV- VLPs (pVLPs), we demonstrated that combination of intranasal primes and intravaginal boosts is optimal to elicit both humoral and cellular memory responses in mucosa. Interestingly, our results show that in contrast to proteins, particulate antigens induce high-quality humoral responses characterized by a high breadth, long-term neutralizing activity and cross-clade reactivity, accompanying with high T follicular helper cell (TFH) response. These results underscore the potential of a VLP-based vaccine in effectively instigating long-lasting, HIV-specific immunity and point out the specific role of particulate antigen form in driving high-quality mucosal immune responses.

Litifilimab (BIIB059), a promising investigational drug for cutaneous lupus erythematosus.

INTRODUCTION: There are no U.S. Food and Drug Administration (FDA) approved therapies for cutaneous lupus erythematosus (CLE). Litifilimab is a monoclonal antibody against BDCA2, a plasmacytoid dendritic cell-specific antigen, currently under investigation for systemic lupus erythematosus (SLE) and CLE. The LILAC study, published in the New England Journal of Medicine, is a phase II randomized controlled trial for CLE which demonstrated superiority of Litifilimab over placebo using a skin directed outcome measure. AREAS COVERED: This review identifies challenges that have hindered the development of any approved treatments for CLE, recent SLE trials that include skin disease data, and the pharmacological properties of litifilimab. We review the clinical efficacy and safety of litifilimab for both SLE and CLE in the phase I and II clinical trials. This review aims to highlight the need for more CLE-specific clinical trials and examine the potential of litifilimab as the first FDA approved therapy for CLE. (Clinical trial registration: www.clinicaltrials.gov identifier is NCT02847598.). EXPERT OPINION: Litifilimab demonstrated efficacy in a randomized phase II clinical trial as a standalone CLE trial using validated skin-specific outcome measures, making it the first successful clinical trial for a CLE targeted therapy. If approved, litifilimab will be a pivotal change in the landscape of CLE management especially for severe and refractory disease.

Insurance delays in the approval of biologic medications for patients with psoriasis and psoriatic arthritis.

Biologics are the most effective treatment for moderate-to-severe psoriasis. Insurance approval and need for prior authorization continue to be a barrier to care for many patients with psoriasis and psoriatic arthritis. We sought to determine whether race/ethnicity, insurance type, and provider specialty affect biologic approval times. Records from the University of Miami Health System were reviewed, and 101 patients were included. Need for a prior authorization was significantly associated with long waits (p = 2.4 × 10-5). We did not identify a significant difference in wait times between non-Hispanic Whites and non-Whites. The average wait time for biologic approval for Whites was 29.7 days and for non-Whites was 27.2 days. Biologics were approved the same day for 23.7% of HMO carriers, 11.5% of PPO carriers, 63% of Medicare carriers, and 40% of Medicaid carriers (p < 0.001). There was no difference in the biologic type prescribed based on insurance type. Medicaid (p < 0.05) and the need for prior authorization (p = 2.4 × 10-5) significantly predicted approval wait time in our multilinear regression model. Patients with Medicare had the shortest wait time with a mean of 7.3 days. Medicaid patients waited a mean of 11.3 days. Private insurance patients waited the longest, regardless of whether they had a PPO (37 days) or HMO (41.3 days).

Low-dose interleukin-2 therapy in active systemic lupus erythematosus (LUPIL-2): a multicentre, double-blind, randomised and placebo-controlled phase II trial.

OBJECTIVES: A regulatory T cell (Treg) insufficiency due to shortage of interleukin-2 (IL-2) is central to the pathophysiology of systemic lupus erythematosus (SLE). We performed a multicentre, double-blinded, randomised, placebo-controlled phase II proof-of-concept trial to evaluate the efficacy of low-dose IL-2 therapy in patients with SLE having moderate-to-severe disease activity while receiving standard treatment. METHODS: We randomly assigned 100 patients in a 1:1 ratio to receive either 1.5 million IU/day of subcutaneous IL-2 (ILT-101) or placebo for 5 days followed by weekly injections for 12 weeks. Clinical efficacy was assessed at week 12 in a predefined hierarchical analysis of (1) the SLE responder index-4 (SRI-4) response as a primary end point, and of (2) relative and (3) absolute changes in the Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index scores as key secondary end points. RESULTS: The primary end point was not met in the intention-to-treat population (ILT-101: 68%, placebo: 58%; p=0.3439), due to a 100% SRI-4 response rate in the placebo group from the two sites from Bulgaria. A post hoc per-protocol analysis on a prespecified population that excluded patients from these two sites (n=53) showed a statistically significant difference for the SRI-4 response rate (ILT-101: 83.3%; placebo: 51.7%; p=0.0168), and for the two key secondary end points, accompanied by differences in several secondary exploratory end points. ILT-101 was well tolerated and there was no generation of antidrug antibodies. CONCLUSIONS: The post hoc hierarchical analysis of the primary and key secondary end points in a per-protocol population, complemented by the exploratory analyses of multiple other secondary end points, support that low-dose IL-2 is beneficial in active SLE. TRIAL REGISTRATION NUMBER: NCT02955615.

Multidimensional Immune Profiling of Cutaneous Lupus Erythematosus In Vivo Stratified by Patient Response to Antimalarials.

OBJECTIVE: The pathogenesis of cutaneous lupus erythematosus (CLE) is multifactorial, and CLE is difficult to treat due to the heterogeneity of inflammatory processes among patients. Antimalarials such as hydroxychloroquine (HCQ) and quinacrine (QC) have long been used as first-line systemic therapy; however, many patients do not respond to treatment with antimalarials and require systemic immunosuppressants that produce undesirable side effects. Given the complexity and the unpredictability of responses to antimalarial treatments in CLE patients, we sought to characterize the immunologic profile of patients with CLE stratified by subsequent treatment outcomes to identify potential biomarkers of inducible response. METHODS: We performed mass cytometry imaging of multiple immune cell types and inflammation markers in treatment-naive skin biopsy samples from 48 patients with CLE to identify baseline immunophenotypes that may predict the response to antimalarial therapy. Patients were stratified according to their response to treatment with antimalarials, as HCQ responders, QC responders, or nonresponders. RESULTS: HCQ responders demonstrated increased CD4+ T cells compared to the QC responder group. Patients in the nonresponder group were found to have decreased Treg cells compared to QC responders and increased central memory T cells compared to HCQ responders. QC responders expressed increased phosphorylated stimulator of interferon genes (pSTING) and interferon-κ (IFNκ) compared to HCQ responders. Phosphorylated STING and IFNκ were found to be localized to conventional dendritic cells (cDCs), and the intensity of pSTING and IFNκ staining was positively correlated with the number of cDCs on a tissue and cellular level. Neighborhood analysis revealed decreased regulatory cell interactions in nonresponder patients. Hierarchical clustering revealed that nonresponder patients could be further differentiated based on expression of pSTAT2, pSTAT3, pSTAT4, pSTAT5, phosphorylated interferon regulatory factor 3 (pIRF3), granzyme B, pJAK2, interleukin-4 (IL-4), IL-17, and IFNγ. CONCLUSION: These findings indicate differential immune cell compositions between patients with CLE, offering guidance for future research on precision-based medicine and treatment response.

Identification of Similarities Between Skin Lesions in Patients With Antisynthetase Syndrome and Skin Lesions in Patients With Dermatomyositis by Highly Multiplexed Imaging Mass Cytometry.

OBJECTIVE: Antisynthetase syndrome (ASyS) and dermatomyositis (DM) are autoimmune disorders that overlap clinically. Given the presence of DM-like skin lesions in ASyS patients, there is debate about whether ASyS is a distinct disease or a subclassification of DM. Recent studies identified differences in type I interferon (IFN) expression between ASyS and DM muscle and finger eruptions. This study was undertaken to elucidate similarities and differences in the pathogenesis of cutaneous disease in ASyS and DM at the single-cell level. METHODS: Five ASyS patients and 7 DM patients were recruited from a prospectively collected database of well-characterized DM patients. ASyS patients were clinically confirmed as having ASyS according to the Connors et al criteria and the Solomon et al criteria and the presence of aminoacyl-transfer RNA synthetase antibodies. Immunophenotyping was conducted using immunofluorescence (IF) and imaging mass cytometry (IMC). RESULTS: IF staining for MxA and IFNß expression revealed up-regulation of type I IFN in ASyS and DM samples compared to healthy control samples (P < 0.05). IMC showed similar numbers of macrophages, T cells, B cells, and dendritic cells in ASyS and DM samples, with no differences in counts (P > 0.05), but an increase in myeloid dendritic cell percentage in DM samples (P < 0.05). Key type I IFN, cytokine, and JAK/STAT pathways were similarly expressed in both ASyS and DM (P > 0.05). At the single-cell level, macrophages positive for phosphorylated stimulator of IFN genes in ASyS samples expressed increased levels of tumor necrosis factor, interluekin-17 (IL-17), and IFNß (P < 0.001). CONCLUSION: IMC is a powerful tool that identifies a role for the type I IFN system in DM-like skin lesions in ASyS and DM with some differences at the cellular level, but overall significant overlap, supporting similar therapeutic decision making.

Plasma-derived DNA containing-extracellular vesicles induce STING-mediated proinflammatory responses in dermatomyositis.

Objectives: Extracellular vesicles (EVs) are lipid bilayer membrane vesicles that are present in various bodily fluids and have been implicated in autoimmune disease pathogenesis. Type I interferons (IFN), specifically IFN-ß, are uniquely elevated in dermatomyositis (DM). The stimulator of interferon genes (STING) works as a critical nucleic acid sensor and adaptor in type I IFN signaling with possible implications in autoimmune diseases such as DM. In the current study, we investigated whether circulating EVs contribute to proinflammatory effects in DM, whether these proinflammatory responses are mediated by the STING signaling pathway, and if so, by what mechanism STING is activated. Methods: We collected and characterized EVs from plasma of healthy controls (HC) and DM patients; analyzed their abilities to trigger proinflammatory cytokines release by ELISA, and explored STING signaling pathway activation using immunoblot and immunofluorescent staining. STING signaling pathway inhibitors and RNAi were used to further investigate whether STING was involved in EVs-triggered proinflammatory response. DNase/lipid destabilizing agent was utilized to digest EVs and their captured DNA contents to evaluate how EVs triggered STING-mediated proinflammatory response in DM. Results: EVs isolated from DM plasma triggered proinflammatory cytokines including type I IFN release with STING signaling pathway activation. The activated STING pathway was preferentially mediated by dsDNA captured by EVs. Suppression of STING or its downstream signaling proteins attenuated the EVs-mediated proinflammatory response. Conclusions: Plasma-derived, DNA containing-EVs induced STING-mediated proinflammatory effects in DM. Targeting the STING pathway may be a potential therapeutic approach for DM.