Ectopic lymphoid structures (ELSs) in the rheumatoid synovial joints sustain autoreactivity against locally expressed autoantigens. We recently identified recombinant monoclonal antibodies (RA- ...rmAbs) derived from single, locally differentiated rheumatoid arthritis (RA) synovial B cells, which specifically recognize fibroblast-like synoviocytes (FLSs).
ObjectivesMast cells (MCs) are involved in the pathogenesis of rheumatoid arthritis (RA). However, their contribution remains controversial. To establish their role in RA, we analysed their presence ...in the synovium of treatment-naïve patients with early RA and their association and functional relationship with histological features of synovitis.MethodsSynovial tissue was obtained by ultrasound-guided biopsy from treatment-naïve patients with early RA (n=99). Immune cells (CD3/CD20/CD138/CD68) and their relationship with CD117+MCs in synovial tissue were analysed by immunohistochemistry (IHC) and immunofluorescence (IF). The functional involvement of MCs in ectopic lymphoid structures (ELS) was investigated in vitro, by coculturing MCs with naïve B cells and anticitrullinated protein antibodies (ACPA)-producing B cell clones, and in vivo in interleukin-27 receptor alpha (IL27ra)-deficient and control mice during antigen-induced arthritis (AIA).ResultsHigh synovial MC counts are associated with local and systemic inflammation, autoantibody positivity and high disease activity. IHC/IF showed that MCs reside at the outer border of lymphoid aggregates. Furthermore, human MCs promote the activation and differentiation of naïve B cells and induce the production of ACPA, mainly via contact-dependent interactions. In AIA, synovial MC numbers increase in IL27ra deficient mice, in association with ELS and worse disease activity.ConclusionsSynovial MCs identify early RA patients with a severe clinical form of synovitis characterised by the presence of ELS.
Autoimmune diseases (AIDs) share similar serological, clinical, and radiological findings, but, behind these common features, there are different pathogenic mechanisms, immune cells dysfunctions, and ...targeted organs. In this context, multiple lines of evidence suggest the application of precision medicine principles to AIDs to reduce the treatment failure.
Precision medicine refers to the tailoring of therapeutic strategies to the individual characteristics of each patient, thus it could be a new approach for management of AIDS which considers individual variability in genes, environmental exposure, and lifestyle. Precision medicine would also assist physicians in choosing the right treatment, the best timing of administration, consequently trying to maximize drug efficacy, and, possibly, reducing adverse events.
In this work, the growing body of evidence is summarized regarding the predictive factors for drug response in patients with AIDs, applying the precision medicine principles to provide high-quality evidence for therapeutic opportunities in improving the management of these patients.
BackgroundSynovial tissue research has become widely developed in several rheumatology centres, however, large discrepancies exist in the way synovial tissue is handled and, more specifically, how ...data pertaining to biopsy procedure, quality check and experimental results are reported in the literature. This heterogeneity hampers the progress of research in this rapidly expanding field. In that context, under the umbrella of European Alliance of Associations for Rheumatology, we aimed at proposing points to consider (PtC) for minimal reporting requirements in synovial tissue research.MethodsTwenty-five members from 10 countries across Europe and USA met virtually to define the key areas needing evaluation and formulating the research questions to inform a systematic literature review (SLR). The results were presented during a second virtual meeting where PtC were formulated and agreed.ResultsStudy design, biopsy procedures, tissue handling, tissue quality control and tissue outcomes (imaging, DNA/RNA analysis and disaggregation) were identified as important aspects for the quality of synovial tissue research. The SLR interrogated four databases, retrieved 7654 abstracts and included 26 manuscripts. Three OPs and nine PtC were formulated covering the following areas: description of biopsy procedure, overarching clinical design, patient characteristics, tissue handling and processing, quality control, histopathology, transcriptomic analyses and single-cell technologies.ConclusionsThese PtC provide guidance on how research involving synovial tissue should be reported to ensure a better evaluation of results by readers, reviewers and the broader scientific community. We anticipate that these PtC will enable the field to progress in a robust and transparent manner over the coming years.
Both TLR7 and NF-κB hyperactivity are known to contribute to pathogenesis in Systemic Lupus Erythematosus (SLE), driving a pro-interferon response, autoreactive B cell expansion and autoantibody ...production. UBE2L3 is an SLE susceptibility gene which drives plasmablast/plasma cell expansion in SLE, but its role in TLR7 signalling has not been elucidated. We aimed to investigate the role of UBE2L3 in TLR7-mediated NF-κB activation, and the effect of UBE2L3 inhibition by Dimethyl Fumarate (DMF) on SLE B cell differentiation in vitro. Our data demonstrate that UBE2L3 is critical for activation of NF-κB downstream of TLR7 stimulation, via interaction with LUBAC. DMF, which directly inhibits UBE2L3, significantly inhibited TLR7-induced NF-κB activation, differentiation of memory B cells and plasmablasts, and autoantibody secretion in SLE. DMF also downregulated interferon signature genes and plasma cell transcriptional programmes.
These results demonstrate that UBE2L3 inhibition could potentially be used as a therapy in SLE through repurposing of DMF, thus preventing TLR7-driven autoreactive B cell maturation.
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•Linear Ubiquitination is activated following TLR7.•UBE2L3 mediates NF-κB activation following TLR7 stimulation.•UBE2L3 is necessary for NF-κB activation and autoreactive plasmablast development.•UBE2L3 is inhibited by dimethyl fumarate (DMF).•DMF suppresses plasma cell differentiation and alters the transcriptional programmes.
Objective
This study aimed to identify peripheral and salivary gland (SG) biomarkers of response/resistance to B cell depletion based on the novel concise Composite of Relevant Endpoints for Sjögren ...Syndrome (cCRESS) and candidate Sjögren Tool for Assessing Response (STAR) composite endpoints.
Methods
Longitudinal analysis of peripheral blood and SG biopsies was performed pre‐ and post‐treatment from the Trial of Anti–B Cell Therapy in Patients With Primary Sjögren Syndrome (TRACTISS) combining flow cytometry immunophenotyping, serum cytokines, and SG bulk RNA sequencing.
Results
Rituximab treatment prevented the worsening of SG inflammation observed in the placebo arm, by inhibiting the accumulation of class‐switched memory B cells within the SG. Furthermore, rituximab significantly down‐regulated genes involved in immune‐cell recruitment, lymphoid organization alongside antigen presentation, and T cell co‐stimulatory pathways. In the peripheral compartment, rituximab down‐regulated immunoglobulins and auto‐antibodies together with pro‐inflammatory cytokines and chemokines. Interestingly, patients classified as responders according to STAR displayed significantly higher baseline levels of C‐X‐C motif chemokine ligand‐13 (CXCL13), interleukin (IL)‐22, IL‐17A, IL‐17F, and tumor necrosis factor‐α (TNF‐α), whereas a longitudinal analysis of serum T cell–related cytokines showed a selective reduction in both STAR and cCRESS responder patients. Conversely, cCRESS response was better associated with biomarkers of SG immunopathology, with cCRESS‐responders showing a significant decrease in SG B cell infiltration and reduced expression of transcriptional gene modules related to T cell costimulation, complement activation, and Fcγ‐receptor engagement. Finally, cCRESS and STAR response were associated with a significant improvement in SG exocrine function linked to transcriptional evidence of SG epithelial and metabolic restoration.
Conclusion
Rituximab modulates both peripheral and SG inflammation, preventing the deterioration of exocrine function with functional and metabolic restoration of the glandular epithelium. Response assessed by newly developed cCRESS and STAR criteria was associated with differential modulation of peripheral and SG biomarkers, emerging as novel tools for patient stratification.
Abstract
Background
Psoriatic arthritis (PsA) and rheumatoid arthritis (RA) are clinically distinct autoimmune joint disorders both marked by the chronic infiltration of the synovial tissue (ST) by ...inflammatory cells. It has been proposed that a more prominent thickening of the lining layer and a higher number of T/B-cells within the sublining characterised RA-ST. However, in most studies, patients had established disease and were already exposed to treatments. Furthermore, a prevalent number of samples from large joints may have affected these conclusions. Here, we intended to portrait the histological and molecular characteristics of the PsA-ST before any therapeutic modulation and early in the disease in comparison with RA and correlate them with the clinical features.
Methods
183 consecutive patients naïve to DMARDs/steroids with ongoing symptoms for less than 12 months and at least one inflamed joint entered the Pathobiology of Early Arthritis Cohort (PEAC) at the Barts Health NHS Trust and underwent a US-guided synovial biopsy. ST was immuno-stained for CD3-CD20-CD138-CD68 to quantify the cellular infiltrate by T-cells, B-cells, plasma cells and macrophages, respectively. Based on the semi-quantitative score (0-4) of the immune markers, patients were categorised in lympho-myeloid (CD20≥2 or CD138>2), diffuse-myeloid (CD68 sublining≥2, CD20 and CD138<2) and pauci-immune (CD68sublining<2 and/or CD3-CD20-CD138<1). Molecular analysis was performed using RNA-sequencing of 93 RA and 15 PsA-ST. RNA cellular content was quantified using Fantom5-gene-modules.
Results
Of 183 patients, 39 were diagnosed with PsA (32 polyarticular, 7 oligoarticular) and 144 with RA (2010 ACR/EULAR criteria). Age was significantly lower in PsA patients. Small joints were biopsied in 74.4% of PsA and 82% of RA patients. US-synovial thickening score of the biopsied joint was, on average, higher in PsA while the power-doppler signal was similar. The histological comparison proved fewer infiltrating T/B-cells, plasma cells and sublining macrophages in PsA than RA, yet a comparable macrophage composition of the lining. The pathotypes' distribution was different, with prevalent pauci-immune in PsA (43.2%) and lympho-myeloid in RA (43.2%). At baseline, the number of tender/swollen joints was significantly higher in RA, while there were no differences in other clinical parameters such as DAS28. In PsA, synovial pathotypes did not define clinical phenotypes, whereas RA pauci-immune patients had less severe disease activity than lympho-myeloid; this relation was confirmed in an age/gender-matched to PsA subset of 26 RA subjects. The molecular profiling revealed that PsA-ST composition had a greater content of fibroblasts, eosinophils and neutrophils. Moreover, PsA-ST had higher expression of neutrophil recruitment/enrichment, cell migration and cytoskeleton remodelling gene-modules clusters.
Conclusion
Discovering distinct synovial tissue signatures characterising early treatment-naive PsA will provide a better understanding of the disease pathogenesis and suggest innovative therapeutic targets.
Disclosures
A. Nerviani None. G. Lliso-Ribera None. M. Boutet None. K. Goldmann None. F. Rivellese None. S. Kelly None. M. Bombardieri None. M. Lewis None. F. Humby None. C. Pitzalis None.
Objective
Ectopic lymphoid structures (
ELS
) develop at sites of infection, autoimmunity, and cancer. In patients with Sjögren's syndrome (
SS
),
ELS
support autoreactive B cell activation and ...lymphomagenesis. Interleukin‐27 (
IL
‐27) is a key regulator of adaptive immunity and limits Th17 cell–driven pathology. We undertook this study to elucidate the role of
IL
‐27 in
ELS
formation and function in autoimmunity using a murine model of sialadenitis and in patients with
SS
.
Methods
ELS
formation was induced in wild‐type and
Il27ra
−
/
−
mice via salivary gland (
SG
) cannulation of a replication‐deficient adenovirus in the presence or absence of
IL
‐17A neutralization. In
SG
biopsy samples,
IL
‐27–producing cells were identified by multicolor immunofluorescence microscopy. Lesional and circulating
IL
‐27 levels were determined by gene expression and enzyme‐linked immunosorbent assay. The in vitro effect of
IL
‐27 on T cells was assessed using fluorescence‐activated cell sorting and cytokine release.
Results
In experimental sialadenitis,
Il27ra
−/−
mice had larger and more hyperactive
ELS
(focus score;
P
< 0.001), increased autoimmunity, and an expanded Th17 response (
P
< 0.001), compared to wild‐type mice.
IL
‐17 blockade in
Il27ra
−
/
−
mice suppressed the aberrant
ELS
response (B and T cell reduction against control;
P
< 0.01).
SS
patients displayed increased circulating
IL
‐27 levels (
P
< 0.01), and in
SG
biopsy samples,
IL
‐27 was expressed by
DC
‐
LAMP
+ dendritic cells in association with
CD
3+ T cells. Remarkably, in
SS
T cells (but not in T cells from patients with rheumatoid arthritis or healthy controls),
IL
‐27–mediated suppression of
IL
‐17 secretion was severely impaired and associated with an aberrant interferon‐γ release upon
IL
‐27 stimulation.
Conclusion
Our data indicate that the physiologic ability of
IL
‐27 to limit the magnitude and function of
ELS
through control of Th17 cell expansion is severely impaired in
SS
patients, highlighting a defective immunoregulatory checkpoint in this condition.
Objective
Ectopic lymphoid structures (ELS) develop at sites of infection, autoimmunity, and cancer. In patients with Sjögren's syndrome (SS), ELS support autoreactive B cell activation and ...lymphomagenesis. Interleukin‐27 (IL‐27) is a key regulator of adaptive immunity and limits Th17 cell–driven pathology. We undertook this study to elucidate the role of IL‐27 in ELS formation and function in autoimmunity using a murine model of sialadenitis and in patients with SS.
Methods
ELS formation was induced in wild‐type and Il27ra−/− mice via salivary gland (SG) cannulation of a replication‐deficient adenovirus in the presence or absence of IL‐17A neutralization. In SG biopsy samples, IL‐27–producing cells were identified by multicolor immunofluorescence microscopy. Lesional and circulating IL‐27 levels were determined by gene expression and enzyme‐linked immunosorbent assay. The in vitro effect of IL‐27 on T cells was assessed using fluorescence‐activated cell sorting and cytokine release.
Results
In experimental sialadenitis, Il27ra−/− mice had larger and more hyperactive ELS (focus score; P < 0.001), increased autoimmunity, and an expanded Th17 response (P < 0.001), compared to wild‐type mice. IL‐17 blockade in Il27ra−/− mice suppressed the aberrant ELS response (B and T cell reduction against control; P < 0.01). SS patients displayed increased circulating IL‐27 levels (P < 0.01), and in SG biopsy samples, IL‐27 was expressed by DC‐LAMP+ dendritic cells in association with CD3+ T cells. Remarkably, in SS T cells (but not in T cells from patients with rheumatoid arthritis or healthy controls), IL‐27–mediated suppression of IL‐17 secretion was severely impaired and associated with an aberrant interferon‐γ release upon IL‐27 stimulation.
Conclusion
Our data indicate that the physiologic ability of IL‐27 to limit the magnitude and function of ELS through control of Th17 cell expansion is severely impaired in SS patients, highlighting a defective immunoregulatory checkpoint in this condition.
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