A public health approach to modern slavery in the United Kingdom: a codeveloped framework

OBJECTIVES

Modern slavery is a public health challenge. The objective of this research was to build and refine a public health approach to addressing it.

STUDY DESIGN

This was a participatory qualitative study with a proof-of-concept exercise.

METHODS

Nine deliberative workshops with 65 people working across the antislavery sector. Thematic analysis of qualitative data. Of the nine workshops, two were proof of concept. These explored and tested the public health framework devised.

RESULTS

Participants contributed to the development of a public health framework to modern slavery that included multiple elements across national, local, and service levels. There were six 'C's to national components: policy that was coherent, co-ordinated, consistent, comprehensive, co-operative and compliant with international law. Local components centred on effective local multiagency partnerships and service design and delivery focussed on trauma-informed, flexible, person-centred care.

CONCLUSIONS

A public health approach to modern slavery is a promising development in the antislavery field in the United Kingdom and globally. It was well supported by workshop participants and appeared to be operable. Barriers to its implementation exist, however, including the challenge of intersectoral working and an incongruent policy environment.

Diagnostic Accuracy Study of the Pediatric-Specific Ultrasound Scoring System for the Knee Joint in Children With Juvenile Idiopathic Arthritis

OBJECTIVE

We undertook this study to validate the Pediatric Arthritis Ultrasound Scoring System for the knee joint (PAUSS-knee) in children with juvenile idiopathic arthritis (JIA).

METHODS

Children with JIA were enrolled to prospectively receive a musculoskeletal ultrasound (MSUS) examination of the knee and a physical examination to determine presence/absence of clinical arthritis. MSUS images were scored using the PAUSS-knee, a semiquantitative MSUS scoring system (0-3, normal to severe) for B-mode and power Doppler mode. In addition to MSUS, a subset of participants also received magnetic resonance imaging (MRI) of the knee, which was scored according to the combined Juvenile Arthritis MRI Scoring (JAMRIS) system. Spearman's correlations (rs ) were used to calculate associations between variables. Test characteristics of the PAUSS-knee were calculated with MRI as the reference standard. Inflammatory biomarkers were assessed in synovial fluid from involved knees.

RESULTS

Eighty children with JIA contributed 112 MSUSs and 25 MRIs of the knee. Of the knees, 41% (n = 46) had clinical evidence of arthritis. The B-mode PAUSS-knee score moderately correlated with clinically determined arthritis (rs = 0.54, P < 0.001) and strongly correlated with the JAMRIS score (rs = 0.75, P < 0.001). Compared with MRI, the area under the curve for the B-mode PAUSS-knee was 0.92. For a cutoff of >1, the B-mode PAUSS-knee had a sensitivity of 83% and specificity of 82%. Biomarker analysis indicates that interleukin-2R levels correlate with PAUSS score.

CONCLUSION

Our data indicate that the PAUSS-knee has excellent accuracy for the diagnosis of arthritis when compared with MRI. The PAUSS-knee has the potential to effectively inform JIA medical decision-making in real time.

Implementing Research Shared (Core) Facility Billing Systems

Research Shared (core) Facilities (RSF) operate as centers of expertise and help to accelerate basic and translational science. A centralized platform for unified ordering, equipment reservation, and the billing of services using an integrated software system is a valuable resource that many academic institutions should consider. This paper discusses considerations for best practices and identifies lessons learned from the implementation of two different software systems for RSF. After implementing two different centralized billing systems for RSF, this paper identifies considerations for best practices and discusses lessons learned.

Establishing a biosafety plan for a flow cytometry shared resource laboratory

A biosafety plan is essential to establish appropriate practices for biosafety in a shared resource laboratory (SRL). A biosafety plan will contain the essential information for the use of biological samples on specific instrumentation, their apparent risks, and the steps that should be taken to mitigate these risks. Establishment of a biosafety plan can be a daunting task as the variety of pathogens that come through the SRL is highly diverse and may change over time; however, having a plan that can adapt to this variety will provide a framework for addressing concerns and educating personnel and users on biosafety practices. Using resources available at your institution and developing a robust relationship with health and safety personnel at your institution is key to generating an effective biosafety plan. Here we provide a basic underlying structure for a biosafety plan to aid SRL personnel in generating or maintaining their biosafety procedures, and provide guidance for establishing a dynamic, living biosafety plan.

Evaluating the Effects of Cell Sorting on Gene Expression

Cell sorting is a commonly used technology to isolate highly purified cell populations for downstream applications. Because the sorted cells are destined for further analysis, i.e., gene expression assays or functional assays, ensuring that the sorting process itself has little effect on the cells is of utmost importance. Previous studies examining the effects of sorting on cellular function have primarily focused on a specific cell type or condition. One of the goals of the Flow Cytometry Research Group of the Association of Biomolecular Resource Facilities is to establish best practice guidelines for cell sorting conditions that minimize cell stress, perturbation, or injury to the sorted cell population. In this study, the effects of nozzle size, sample pressure, UV exposure, and instrument type were evaluated for their effects on gene expression and cell cycle using both established cell lines and primary cells across several flow cytometry shared facilities. Results indicate that nozzle size and pressure, as well as UV exposure and instrument type, have only minor effects on gene expression, which were diminished by subsequent culturing of the sorted cells. In this assessment, these data demonstrate that cell sorting itself, regardless of instrumentation used, has minimal effects on downstream cellular applications.

IFN-γ is essential for alveolar macrophage driven pulmonary inflammation in macrophage activation syndrome

Macrophage activation syndrome (MAS) is a life-threatening cytokine storm complicating systemic juvenile idiopathic arthritis (SJIA) driven by IFNγ. SJIA and MAS are associated with an unexplained emerging lung disease (SJIA-LD), with our recent work supporting pulmonary activation of IFNγ pathways pathologically linking SJIA-LD and MAS. Our objective was to mechanistically define the novel observation of pulmonary inflammation in the TLR9 mouse model of MAS. In acute MAS, lungs exhibit mild but diffuse CD4-predominant, perivascular interstitial inflammation with elevated IFNγ, IFN-induced chemokines, and AMΦ expression of IFNγ-induced genes. Single-cell RNA-sequencing confirmed IFN-driven transcriptional changes across lung cell types with myeloid expansion and detection of MAS-specific macrophage populations. Systemic MAS resolution was associated with increased AMΦ and interstitial lymphocytic infiltration. AMΦ transcriptomic analysis confirmed IFNγ-induced proinflammatory polarization during acute MAS, which switches towards an anti-inflammatory phenotype after systemic MAS resolution. Interestingly, recurrent MAS led to increased alveolar inflammation and lung injury, and reset AMΦ polarization towards a proinflammatory state. Furthermore, in mice bearing macrophages insensitive to IFNγ, both systemic feature of MAS and pulmonary inflammation were attenuated. These findings demonstrate that experimental MAS induces IFNγ-driven pulmonary inflammation replicating key features of SJIA-LD, and provides a model system for testing novel treatments directed towards SJIA-LD.

POS0076 S100A8/A9 AND S100A12 AS POTENTIAL PREDICTIVE BIOMARKERS OF ABATACEPT RESPONSE IN POLYARTICULAR JUVENILE IDIOPATHIC ARTHRITIS

Background:

The calcium-binding proteins S100A8/A9 (calprotectin) and S100A12 (extracellular newly identified receptor for advanced glycation end-products binding protein [EN-RAGE]) are involved in multiple signalling pathways to mediate inflammation, can be secreted by activated monocytes/macrophages and exhibit cytokine-like extracellular functions. Circulating levels of these proteins have been associated with disease and clinical responses in systemic juvenile idiopathic arthritis (sJIA), including treatment response.1 Studies suggest that serum S100A8/A9 and S100A12, which are released at inflammation sites, are more specific biomarkers of local inflammation (e.g. in the synovium) than systemic biomarkers such as CRP and ESR.2,3

Objectives:

To investigate if baseline S100A8/A9 and S100A12 predict clinical response to abatacept treatment in polyarticular JIA (pJIA), and to assess whether changes from baseline in S100A8/A9 or S100A12 can be better prognostic markers for response to abatacept treatment than CRP in pJIA.

Methods:

Data are from a phase III trial of SC abatacept for the treatment of pJIA (NCT01844518).4 This 24-month, single-arm, open-label, international, multicentre, two-part study included male and female patients with pJIA aged 2–17 years. This analysis examined the correlation between biomarkers (S100A8/A9, S100A12 and high-sensitivity CRP [hsCRP]) and disease activity (measured using Juvenile Arthritis Disease Activity Score [JADAS]) at baseline, baseline biomarker values as predictors of future treatment response (ACR and JADAS endpoints), and the correlation between change from baseline in biomarker values and treatment response at Day 113.

Results:

Of 219 total patients, 158 (72%) had S100A8/A9 values and 155 (71%) had S100A12 values at baseline. Median S100A8/A9 and S100A12 values were 3295 ng/mL (normal range, 716–3004 ng/mL) and 176 ng/mL (normal range, 32–385 ng/mL), respectively. S100A8/A9, S100A12 and hsCRP (median 0.20 mg/dL; normal ≤0.6 mg/dL) had a low-to-moderate but significant association with disease activity at baseline; coefficients for associations between JADAS71-CRP low disease activity (LDA) and the biomarkers S100A8/A9, S100A12 and hsCRP were 0.23 (p=0.0038), 0.16 (p=0.0448) and 0.26 (p=0.0001), respectively. Baseline S100A8/A9 level above the median was associated with lower odds of ACR100 at Day 113 (p=0.0052). Figure 1 shows the associations of baseline biomarker values with Day 113 ACR and JADAS scores in the overall population. Baseline S100A8/A9 or S100A12 did not significantly influence ACR50 or ACR70 responses at Day 113, but high baseline values were associated with reduced odds of ACR90 (p=0.01), ACR100 (p=0.005), ACR-inactive disease (ID) (p=0.0001), and JADAS71-CRP (LDA) (p=0.02). By Day 477, elevated baseline S100A12 was still significantly associated with lower odds of ACR100 overall (0.467; p=0.0248) but baseline S100A8/A9 was not; at Day 645, neither was significantly associated with ACR100 response. At Day 113, changes from baseline in S100A8/A9 and S100A12 were correlated with ACR100 (coefficients of 0.22 [p=0.0082] and 0.26 [p=0.0015], respectively) and with ACR-ID (0.22 [p=0.0067] and 0.26 [p=0.0014], respectively); change in hsCRP was not significantly correlated with disease response.

Conclusion:

S100A8/A9 and S100A12 may serve as prognostic biomarkers to predict response to abatacept treatment at Day 113. Changes from baseline S100A8/A9 and S100A12 levels were more highly correlated with efficacy outcomes including ACR100 and ACR-ID at Day 113 compared with hsCRP.

References:

[1]Aljaberi N, et al. Pediatr Rheumatol Online J 2020;18:7.

[2]Hammer H, et al. Arthritis Res Ther 2011;13:R178.

[3]Nordal HH, et al. BMC Musculoskelet Disord 2014;15:335.

[4]Brunner H, et al. Arthritis Rheumatol 2018;70:1144–1154.

Acknowledgements:

Professional medical writing and editorial assistance was provided by Rob Coover, MPH, at Caudex and was funded by Bristol Myers Squibb.

Disclosure of Interests:

Nicolino Ruperto Speakers bureau: NR has received honoraria for consultancies or speaker bureaus (< 10.000 USD each) from the following pharmaceutical companies in the past 3 years: Ablynx, Astrazeneca-Medimmune, Bayer, Biogen, Boehringer, Bristol Myers Squibb, Celgene, Eli Lilly, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sinergie, Sobi and UCB, Consultant of: NR has received honoraria for consultancies or speaker bureaus (< 10.000 USD each) from the following pharmaceutical companies in the past 3 years: Ablynx, Astrazeneca-Medimmune, Bayer, Biogen, Boehringer, Bristol Myers Squibb, Celgene, Eli Lilly, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, Sinergie, Sobi and UCB, Grant/research support from: The IRCCS Istituto Giannina Gaslini (IGG), where NR works as full-time public employee has received contributions (>10.000 USD each) from the following industries in the last 3 years: Bristol Myers Squibb, Eli Lilly, F Hoffmann-La Roche, GlaxoSmithKline, Janssen, Novartis, Pfizer, Sobi. This funding has been reinvested for the research activities of the hospital in a fully independent manner, without any commitment with third parties., Grant Schulert Speakers bureau: Novartis, Consultant of: SOBI, Alyssa Sproles: None declared, Sherry Thornton: None declared, Gabriel Vega Cornejo Speakers bureau: AbbVie, Grant/research support from: Bristol Myers Squibb, Eli Lilly, Janssen, Parexel, Sanofi, Jordi Anton Speakers bureau: AbbVie, Gebro, GlaxoSmithKline, Novartis, Pfizer, Roche, Sobi, Consultant of: AbbVie, Gebro, GlaxoSmithKline, Novartis, Pfizer, Roche, Sobi, Grant/research support from: AbbVie, Amgen, Gebro, GlaxoSmithKline, Lilly, Novartis, Novimmune, Pfizer, Roche, Sanofi, Sobi, Ruben Cuttica Speakers bureau: AbbVie, Bristol Myers Squibb, GlaxoSmithKline, Lilly, Novartis, Pfizer, Roche, UCB, Paid instructor for: AbbVie, Novartis, Pfizer, Roche, Consultant of: AbbVie, Bristol Myers Squibb, GlaxoSmithKline, Lilly, Novartis, Pfizer, Roche, UCB, Michael Henrickson: None declared, Ivan Foeldvari Consultant of: Bristol Myers Squibb, Gilead, Hexal, MEDAC, Novartis, Pfizer, Sanofi, Daniel Kingsbury Consultant of: Pfizer, Margarita Askelson Consultant of: Currently working for Syneos Health providing services to Bristol Myers Squibb, Jinqi Liu Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Sumanta Mukherjee Shareholder of: Bristol Myers Squibb, GlaxoSmithKline, Employee of: Bristol Myers Squibb, GlaxoSmithKline, Robert Wong Shareholder of: Bristol Myers Squibb, Employee of: Bristol Myers Squibb, Daniel J Lovell Speakers bureau: Genentech, Wyeth Pharm, Consultant of: Abbott, Amgen, AstraZeneca, Boehringer Ingelheim, Celgene, GlaxoSmithKline, Hoffman-La Roche, Novartis, Pfizer, Regeneron, Takeda, UBC, Wyeth Pharma, Xoma, Alberto Martini Speakers bureau: AbbVie, Novartis, Consultant of: AbbVie, Eli Lilly, EMD Serono, Idorsia, Janssen, Novartis, Pfizer, Alexei Grom Consultant of: AB2Bio, Novartis, Sobi (NovImmune), Grant/research support from: AB2Bio, Novartis, Sobi (NovImmune), Hermine Brunner Speakers bureau: GlaxoSmithKline, Novartis, Pfizer, Roche, Paid instructor for: Novartis, Pfizer (funds go to CCHMC/employer), Consultant of: Boehringer Ingelheim, Bristol Myers Squibb, GlaxoSmithKline, Janssen, Merck, Novartis, Pfizer, Roche, UCB (funds go to CCHMC/employer), Grant/research support from: Bristol Myers Squibb, Pfizer (funds go to CCHMC/employer).

Biosafety during a pandemic: shared resource laboratories rise to the challenge

Biosafety has always been an important aspect of daily work in any research institution, particularly for cytometry Shared Resources Laboratories (SRLs). SRLs are common‐use spaces that facilitate the sharing of knowledge, expertise, and ideas. This sharing inescapably involves contact and interaction of all those within this working environment on a daily basis. The current pandemic caused by SARS‐CoV‐2 has prompted the re‐evaluation of many policies governing the operations of SRLs. Here we identify and review the unique challenges SRLs face in maintaining biosafety standards, highlighting the potential risks associated with not only cytometry instrumentation and samples, but also the people working with them. We propose possible solutions to safety issues raised by the COVID‐19 pandemic and provide tools for facilities to adapt to evolving guidelines and future challenges.

Monocyte and bone marrow macrophage transcriptional phenotypes in systemic juvenile idiopathic arthritis reveal TRIM8 as a mediator of IFN-γ hyper-responsiveness and risk for macrophage activation syndrome

OBJECTIVES

Systemic juvenile idiopathic arthritis (SJIA) confers high risk for macrophage activation syndrome (MAS), a life-threatening cytokine storm driven by interferon (IFN)-γ. SJIA monocytes display IFN-γ hyper-responsiveness, but the molecular basis of this remains unclear. The objective of this study is to identify circulating monocyte and bone marrow macrophage (BMM) polarisation phenotypes in SJIA including molecular features contributing to IFN response.

METHODS

Bulk RNA-seq was performed on peripheral blood monocytes (n=26 SJIA patients) and single cell (sc) RNA-seq was performed on BMM (n=1). Cultured macrophages were used to define consequences of tripartite motif containing 8 (TRIM8) knockdown on IFN-γ signalling.

RESULTS

Bulk RNA-seq of SJIA monocytes revealed marked transcriptional changes in patients with elevated ferritin levels. We identified substantial overlap with multiple polarisation states but little evidence of IFN-induced signature. Interestingly, among the most highly upregulated genes was TRIM8, a positive regulator of IFN-γ signalling. In contrast to PBMC from SJIA patients without MAS, scRNA-seq of BMM from a patient with SJIA and MAS identified distinct subpopulations of BMM with altered transcriptomes, including upregulated IFN-γ response pathways. These BMM also showed significantly increased expression of TRIM8. In vitro knockdown of TRIM8 in macrophages significantly reduced IFN-γ responsiveness.

CONCLUSIONS

Macrophages with an 'IFN-γ response' phenotype and TRIM8 overexpression were expanded in the bone marrow from an MAS patient. TRIM8 is also upregulated in SJIA monocytes, and augments macrophage IFN-γ response in vitro, providing both a candidate molecular mechanism and potential therapeutic target for monocyte hyper-responsiveness to IFNγ in cytokine storms including MAS.

Remote Training of SRL Users and Staff in a Global Pandemic

The impact of the COVID-19 pandemic on training and Shared Resource Laboratory (SRL) operations such as staffing, facility access, and social distancing, has affected facilities around the globe to different degrees based on restrictions set by various geographical and institutional settings. With these restrictions come unique challenges regarding user and staff training and education, for both theory and practice. Most notably, limitations in facility access, occupancy, staffing availability, network restrictions and trainee engagement call for innovative solutions for training when traditional in-person options are not feasible. Through the use of remote access tools and prerecorded educational and training materials, SRLs are able to overcome these obstacles. Here, we focus on readily available technologies and general guidelines that SRLs in different environments can use for remote cytometry training and education, while highlighting key obstacles that still remain. Although SRLs may face initial struggles in transitioning trainings to a virtual format, remote technologies provide unique opportunities to advance current training programs. © 2020 International Society for Advancement of Cytometry.

Evaluating the Effects of Cell Sorting on Gene Expression

Cell sorting is a commonly used technology to isolate highly purified cell populations for downstream applications. Because the sorted cells are destined for further analysis, i.e., gene expression assays or functional assays, ensuring that the sorting process itself has little effect on the cells is of utmost importance. Previous studies examining the effects of sorting on cellular function have primarily focused on a specific cell type or condition. One of the goals of the Flow Cytometry Research Group of the Association of Biomolecular Resource Facilities is to establish best practice guidelines for cell sorting conditions that minimize cell stress, perturbation, or injury to the sorted cell population. In this study, the effects of nozzle size, sample pressure, UV exposure, and instrument type were evaluated for their effects on gene expression and cell cycle using both established cell lines and primary cells across several flow cytometry shared facilities. Results indicate that nozzle size and pressure, as well as UV exposure and instrument type, have only minor effects on gene expression, which were diminished by subsequent culturing of the sorted cells. In this assessment, these data demonstrate that cell sorting itself, regardless of instrumentation used, has minimal effects on downstream cellular applications.

S100 proteins, cytokines, and chemokines as tear biomarkers in children with juvenile idiopathic arthritis-associated uveitis

PURPOSE

Biomarkers for juvenile idiopathic arthritis-associated uveitis (JIA-U) are needed. We aimed to measure inflammatory biomarkers in tears as a non-invasive method to identify biomarkers of uveitis activity.

METHODS

Tears were collected from children with JIA-U (n=20) and pediatric controls (n=20) using Schirmer strips. S100A8, A9, A12, IL-18, IL-8, IP-10, MCP-1, RANTES, and sICAM-1 were measured by ELISA and Luminex assays. Levels of biomarkers were compared between children with JIA-U and controls, and active and inactive JIA-U.

RESULTS

IL-8, sICAM-1, and S100A12 levels were similar between JIA-U and controls, but differed by activity. Active JIA-U had significantly increased S100A12 compared to inactive JIA-U (mean 27,722.5 pg/ML (SE 1.3) vs. 5,937.2 (1.3), p=0.002), IL-8 (73.5 [1.2] vs. 36.2 [1.2], p=0.009), and sICAM-1 (15,822.7 [1.2) vs. 8,778.0 [1.6], p=0.024).

CONCLUSION

We detected inflammatory biomarkers non-invasively in tears of children with JIA-U. IL-8, sICAM-1, and S100A12 are potential biomarkers for uveitis activity.

Impact of P inputs on source-sink P dynamics of sediment along an agricultural ditch network

Phosphorus (P) loss from intensive dairy farms is a pressure on water quality in agricultural catchments. At farm scale, P sources can enter in-field drains and open ditches, resulting in transfer along ditch networks and delivery into nearby streams. Open ditches could be a potential location for P mitigation if the right location was identified, depending on P sources entering the ditch and the source-sink dynamics at the sediment-water interface. The objective of this study was to identify the right location along a ditch to mitigate P losses on an intensive dairy farm. High spatial resolution grab samples for water quality, along with sediment and bankside samples, were collected along an open ditch network to characterise the P dynamics within the ditch. Phosphorus inputs to the ditch adversely affected water quality, and a step change in P concentrations (increase in mean dissolved reactive phosphorus (DRP) from 0.054 to 0.228 mg L^-1) midway along the section of the ditch sampled, signalled the influence of a point source entering the ditch. Phosphorus inputs altered sediment P sorption properties as P accumulated along the length of the ditch. Accumulation of bankside and sediment labile extractable P, Mehlich 3 P (M3P) (from 13 to 97 mg kg^-1) resulted in a decrease in P binding energies (k) to < 1 L mg^-1 at downstream points and raised the equilibrium P concentrations (EPC₀) from 0.07 to 4.61 mg L^-1 along the ditch. The increase in EPC₀ was in line with increasing dissolved and total P in water, demonstrating the role of sediment downstream in this ditch as a secondary source of P to water. Implementation of intervention measures are needed to both mitigate P loss and remediate sediment to restore the sink properties. In-ditch measures need to account for a physicochemical lag time before improvements in water quality will be observed.

Discovery of SERPINA3 as a candidate urinary biomarker of lupus nephritis activity

Objectives

We used an unbiased proteomics approach to identify candidate urine biomarkers (CUBMs) predictive of LN chronicity and pursued their validation in a larger cohort.

Methods

In this cross-sectional pilot study, we selected urine collected at kidney biopsy from 20 children with varying levels of LN damage (discovery cohort) and performed proteomic analysis using isobaric tags for relative and absolute quantification (iTRAQ). We identified differentially excreted proteins based on degree of LN chronicity and sought to distinguish markers exhibiting different relative expression patterns using hierarchically clustered log10-normalized relative abundance data with linked and distinct functions by biological network analyses. For each CUBM, we performed specific ELISAs on urine from a validation cohort (n = 41) and analysis of variance to detect differences between LN chronicity, with LN activity adjustment. We evaluated for CUBM expression in LN biopsies with immunohistochemistry.

Results

iTRAQ detected 112 proteins in urine from the discovery cohort, 51 quantifiable in all replicates. Simple analysis of variance revealed four differentially expressed, chronicity-correlated proteins (P-values < 0.05). Further correlation and network analyses led to selection of seven CUBMs for LN chronicity. In the validation cohort, none of the CUBMs distinguished LN chronicity degree; however, urine SERPINA3 demonstrated a moderate positive correlation with LN histological activity. Immunohistochemistry further demonstrated SERPINA3 staining in proximal tubular epithelial and endothelial cells.

Conclusion

We identified SERPINA3, a known inhibitor of neutrophil cathepsin G and angiotensin II production, as a potential urine biomarker to help quantify LN activity.

A Multiparameter Flow Cytometry Analysis Panel to Assess CD163 mRNA and Protein in Monocyte and Macrophage Populations in Hyperinflammatory Diseases

CD163 facilitates regulation and resolution of inflammation and removal of free hemoglobin and is highly expressed in myeloid cells from patients with inflammatory disorders, such as systemic juvenile idiopathic arthritis (SJIA) and macrophage activation syndrome (MAS). Our recent studies indicate that regulation of CD163 mRNA expression is a key functional property of polarized monocytes and macrophages and is mediated at the transcriptional and posttranscriptional level, including via microRNAs. The goal of the current study is to develop a multiparameter flow cytometry panel incorporating detection of CD163 mRNA for polarized monocyte and macrophage populations in disorders such as SJIA and MAS. THP-1 cells and CD14⁺ human monocytes were stained using fluorochrome-conjugated Abs to myeloid surface markers, along with CD163 mRNA. Staining for mRNA could reliably detect CD163 expression while simultaneously detecting different macrophage populations using Abs targeting CD14, CD64, CD80, CD163, and CD209. This approach was found to be highly sensitive for increased mRNA expression when macrophages were polarized with IL-10 [M(IL-10)], with a strong signal over a broad range of IL-10 concentrations, and showed distinct kinetics of CD163 mRNA and protein induction upon IL-10 stimulation. Finally, this panel demonstrated clear changes in polarization markers in unstimulated monocytes from patients with SJIA and MAS, including upregulated CD163 mRNA and increased CD64 expression. This approach represents a robust and sensitive system for RNA flow cytometry, useful for studying CD163 expression as part of a multimarker panel for human monocytes and macrophages, with broad applicability to the pathogenesis of hyperinflammatory diseases.

Neutrophils From Children With Systemic Juvenile Idiopathic Arthritis Exhibit Persistent Proinflammatory Activation Despite Long-Standing Clinically Inactive Disease

Background: Systemic juvenile idiopathic arthritis (SJIA) is a chronic childhood arthropathy with features of autoinflammation. Early inflammatory SJIA is associated with expansion and activation of neutrophils with a sepsis-like phenotype, but neutrophil phenotypes present in longstanding and clinically inactive disease (CID) are unknown. The objective of this study was to examine activated neutrophil subsets, S100 alarmin release, and gene expression signatures in children with a spectrum of SJIA disease activity.

Methods: Highly-purified neutrophils were isolated using a two-step procedure of density-gradient centrifugation followed by magnetic-bead based negative selection prior to flow cytometry or cell culture to quantify S100 protein release. Whole transcriptome gene expression profiles were compared in neutrophils from children with both active SJIA and CID.

Results: Patients with SJIA and active systemic features demonstrated a higher proportion of CD16⁺CD62L^lo neutrophil population compared to controls. This neutrophil subset was not seen in patients with CID or patients with active arthritis not exhibiting systemic features. Using imaging flow cytometry, CD16⁺CD62L^lo neutrophils from patients with active SJIA and features of macrophage activation syndrome (MAS) had increased nuclear hypersegmentation compared to CD16⁺CD62L⁺ neutrophils. Serum levels of S100A8/A9 and S100A12 were strongly correlated with peripheral blood neutrophil counts. Neutrophils from active SJIA patients did not show enhanced resting S100 protein release; however, regardless of disease activity, neutrophils from SJIA patients did show enhanced S100A8/A9 release upon PMA stimulation compared to control neutrophils. Furthermore, whole transcriptome analysis of highly purified neutrophils from children with active SJIA identified 214 differentially expressed genes (DEG) compared to neutrophils from healthy controls. The most significantly upregulated gene pathway was Immune System Process, including AIM2, IL18RAP, and NLRC4. Interestingly, this gene set showed intermediate levels of expression in neutrophils from patients with long-standing CID yet persistent serum IL-18 elevation. Indeed, all patient samples regardless of disease activity demonstrated elevated inflammatory gene expression, including inflammasome components and S100A8.

Conclusion: We identify features of neutrophil activation in SJIA patients with both active disease and CID, including a proinflammatory gene expression signature, reflecting persistent innate immune activation. Taken together, these studies expand understanding of neutrophil function in chronic autoinflammatory disorders such as SJIA.

Discovery of tear biomarkers in children with chronic non-infectious anterior uveitis: a pilot study

BACKGROUND

Biomarkers in easily obtained specimens that accurately predict uveitis in children with juvenile idiopathic arthritis (JIA) are needed. Aqueous humor has been studied for biomarkers, but is not routinely available. We evaluated tears from children with chronic anterior uveitis (CAU) for biomarkers reported in aqueous humor. In this pilot study, we used Schirmer strips to collect tears from seven children (nine eyes); three children had JIA- associated uveitis (JIA-U) and four had idiopathic disease (I-CAU). Liquid chromatography-tandem mass spectrometry was used to identify and quantify tear proteins. The Mann-Whitney U test identified differential tear protein expression between children with JIA-U and those with I-CAU.

RESULTS

S100A9, LAP3, TTR, MIF, sCD14, S100A8, and SAA1 were detected in tears of all children; the same cytokines have been reported in aqueous humor of children with JIA-U. Tears from children with JIA-U had higher expression of proteins associated with inflammatory arthritis (SEMA3G, TIMP1, HEXB, ERN1, and SAA1) than tears from those with I-CAU. In addition, we found higher expression of sCD14, S100A8, and SAA1, but lower expression of S100A9, LAP3, TTR, and MIF, in tears from children with JIA-U compared to tears from those with I-CAU.

CONCLUSIONS

Tears contain similar cytokine profiles to aqueous humor in children with CAU and may be a clinically useful source of disease biomarkers. Tears from children with JIA-U also contain cytokines associated with inflammatory arthritis; furthermore, differential expression of other tear proteins as well may provide clues to intrinsic differences between JIA-U and I-CAU, despite their similar clinical phenotypes.

MicroRNA networks associated with active systemic juvenile idiopathic arthritis regulate CD163 expression and anti-inflammatory functions in macrophages through two distinct mechanisms

Systemic juvenile idiopathic arthritis (SJIA) is a severe childhood arthropathy with features of autoinflammation. Monocytes and macrophages in SJIA have a complex phenotype with both pro- and anti-inflammatory properties that combine features of several well characterized in vitro conditions used to activate macrophages. An important anti-inflammatory phenotype is expression of CD163, a scavenger receptor that sequesters toxic pro-inflammatory complexes that is highly expressed in both active SJIA and macrophage activation syndrome (MAS). CD163 is most strongly up-regulated by IL-10 (M(IL-10)), and not by other conditions that reflect features seen in SJIA monocytes such as M(LPS+IC). MicroRNA plays key roles in integrating cellular signals such as those in macrophage polarization, and as such we hypothesize microRNAs regulate macrophage functional responses in SJIA including CD163 expression. We find that 2 microRNAs previously found to be elevated in active SJIA, miR-125a-5p and miR-181c, significantly reduced macrophage CD163 expression through 2 distinct mechanisms. Neither microRNA was elevated in M(IL-10) with robust CD163 expression, but were instead induced in M(LPS+IC) where they restricted CD163 mRNA expression. Mir-181 species directly targeted CD163 mRNA for degradation. In contrast, miR-125a-5p functions indirectly, as transcriptome analysis of miR-125a-5p overexpression identified "cytokine-cytokine receptor interactions" as the most significantly repressed gene pathway, including decreased IL10RA, required for IL-10-mediated CD163 expression. Finally, overexpression of miR-181c inhibited CD163 anti-inflammatory responses to hemoglobin or high mobility group box 1 (HMGB1) complexes. Together, these data show that microRNA utilizes multiple mechanisms to integrate well-characterized polarization phenotypes and regulate macrophage functional properties seen in SJIA.

Urine S100 proteins as potential biomarkers of lupus nephritis activity

Background

Improved, noninvasive biomarkers are needed to accurately detect lupus nephritis (LN) activity. The purpose of this study was to evaluate five S100 proteins (S100A4, S100A6, S100A8/9, and S100A12) in both serum and urine as potential biomarkers of global and renal system-specific disease activity in childhood-onset systemic lupus erythematosus (cSLE).

Methods

In this multicenter study, S100 proteins were measured in the serum and urine of four cSLE cohorts and healthy control subjects using commercial enzyme-linked immunosorbent assays. Patients were divided into cohorts on the basis of biospecimen availability: (1) longitudinal serum, (2) longitudinal urine, (3) cross-sectional serum, and (4) cross-sectional urine. Global and renal disease activity were defined using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and the SLEDAI-2K renal domain score. Nonparametric testing was used for statistical analysis, including the Wilcoxon signed-rank test, Kruskal-Wallis test, Mann-Whitney U test, and Spearman’s rank correlation coefficient.

Results

All urine S100 proteins were elevated in patients with active LN compared with patients with active extrarenal disease and healthy control subjects. All urine S100 protein levels decreased with LN improvement, with S100A4 demonstrating the most significant decrease. Urine S100A4 levels were also higher with proliferative LN than with membranous LN. S100A4 staining in the kidney localized to mononuclear cells, podocytes, and distal tubular epithelial cells. Regardless of the S100 protein tested, serum levels did not change with cSLE improvement.

Conclusions

Higher urine S100 levels are associated with increased LN activity in cSLE, whereas serum S100 levels do not correlate with disease activity. Urine S100A4 shows the most promise as an LN activity biomarker, given its pronounced decrease with LN improvement, isolated elevation in urine, and positive staining in resident renal cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1444-4) contains supplementary material, which is available to authorized users.

Thrombin promotes diet-induced obesity through fibrin-driven inflammation

Obesity promotes a chronic inflammatory and hypercoagulable state that drives cardiovascular disease, type 2 diabetes, fatty liver disease, and several cancers. Elevated thrombin activity underlies obesity-linked thromboembolic events, but the mechanistic links between the thrombin/fibrin(ogen) axis and obesity-associated pathologies are incompletely understood. In this work, immunohistochemical studies identified extravascular fibrin deposits within white adipose tissue and liver as distinct features of mice fed a high-fat diet (HFD) as well as obese patients. Fibγ390-396A mice carrying a mutant form of fibrinogen incapable of binding leukocyte αMβ2-integrin were protected from HFD-induced weight gain and elevated adiposity. Fibγ390-396A mice had markedly diminished systemic, adipose, and hepatic inflammation with reduced macrophage counts within white adipose tissue, as well as near-complete protection from development of fatty liver disease and glucose dysmetabolism. Homozygous thrombomodulin-mutant ThbdPro mice, which have elevated thrombin procoagulant function, gained more weight and developed exacerbated fatty liver disease when fed a HFD compared with WT mice. In contrast, treatment with dabigatran, a direct thrombin inhibitor, limited HFD-induced obesity development and suppressed progression of sequelae in mice with established obesity. Collectively, these data provide proof of concept that targeting thrombin or fibrin(ogen) may limit pathologies in obese patients.

Monocyte MicroRNA Expression in Active Systemic Juvenile Idiopathic Arthritis Implicates MicroRNA-125a-5p in Polarized Monocyte Phenotypes

OBJECTIVE

Systemic juvenile idiopathic arthritis (JIA) is an inflammatory disease of childhood in which cells of the monomyelocytoid lineage are thought to be key effector cells. Monocytes from patients with systemic JIA have a distinct phenotype, with features of both M1 and M2 alternative activation. MicroRNAs are critical regulators of monocyte polarization and function, but cellular microRNAs in systemic JIA have not been examined systematically.

METHODS

MicroRNA TaqMan arrays were used to determine the expression profiles of monocytes from children with systemic JIA. Expression of microRNA-125a-5p (miR-125a-5p) and its contribution to monocyte polarization were examined using in vitro-polarized THP-1 cells and primary human monocytes.

RESULTS

A total of 110 microRNAs were found to be differentially expressed in monocytes from patients with active systemic JIA, including molecules implicated in rheumatoid arthritis pathogenesis, cytokine production, and monocyte polarization. MicroRNA-125a-5p was identified as being highly up-regulated in monocytes from children with active systemic JIA, as compared to those from children with clinically inactive JIA or those with active polyarticular JIA, and correlated with systemic features of the disease. In vitro, monocyte miR125a-5p expression was increased after polarization under M2b or M2c conditions. Inhibition of miR-125a-5p showed that this microRNA contributed to full polarization of M2b regulatory macrophages. In contrast, miR-125a-5p overexpression enhanced M2b polarization and altered other polarized populations, including increasing the production of M2 markers. Indeed, in vitro overexpression of this microRNA altered the macrophage phenotype toward that observed in systemic JIA.

CONCLUSION

Children with active systemic JIA have profound alterations in the expression of microRNAs that are implicated in monocyte function and polarization. One of these microRNAs, miR-125a-5p, is also a regulator of immunoregulatory M2b macrophages.

Cγ1 Deficiency Exacerbates Collagen-Induced Arthritis

OBJECTIVE

IgG antibodies protect by aggregating pathogens and activating complement and stimulatory Fcγ receptors (FcγR). Although IgG1 accounts for a large percentage of murine serum antibodies, it poorly activates complement, binds more avidly to inhibitory FcγRIIb than to stimulatory FcγRIII, and has a relatively low aggregating ability. We previously demonstrated that IgG1 protects against complement- and FcγR-independent renal disease by inhibiting immune complex obstruction of glomerular capillaries. The purpose of this study was to determine whether IgG1 also protects against the complement- and FcγR-dependent disorder, collagen-induced arthritis (CIA).

METHODS

CIA was induced by injecting mice with type II collagen (CII) (active model) or with IgG2a and IgG2b anti-CII monoclonal antibodies (ArthritoMab) (passive model). Arthritis severity was assessed, and CII-specific IgG was titered.

RESULTS

Cγ1-deficient C57BL/6 mice lack IgG1 (IgG1(-/-) ); in these mice, arthritis developed at a higher frequency and was more severe compared with IgG1(+/+) mice in the active model. Disease was FcγRIII- and C3-dependent in both the IgG(+/+) and IgG(-/-) mouse strains and was not influenced by interleukin-4 receptor α in either strain. CII-specific IgG2a/c titers were considerably higher in IgG1(-/-) than in IgG1(+/+) mice and correlated with CIA incidence and severity. IgG1(+/+) mice that developed CIA had higher CII-specific IgG1 and IgG2a/c levels than did those without CIA. CII-inoculated BALB/c IgG1(+/+) and IgG1(-/-) mice had much lower CII-specific IgG2a/c titers than did C57BL/6 mice and failed to develop CIA but developed passive CIA when given ArthritoMab.

CONCLUSION

The absence of a functional Cγ1 gene indirectly promotes the development of CIA, likely through increased production of IgG2a/c, an isotype that strongly activates complement and stimulatory FcγR.

Measurement of citrate in urine using liquid chromatography tandem mass spectrometry: comparison with an enzymatic method

Background: Measurement of urine citrate is used to assess the risk of further urinary stone formation and to assess the benefit of treatment in affected individuals. We wanted to develop a simple and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of urinary citrate and to compare it with our current enzymatic assay.

Methods: For the LC-MS/MS assay, samples were prepared in a deep-well block by adding 10 µL of urine and 20 µL of internal standard to 400 µL of water. After mixing, 3 µL of the diluted sample was injected into the LC-MS/MS system. An LC system was used to isocratically elute a C18 column (50 x 2.1 mm) with 0.4 mL/min water containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid. A step gradient of 100% methanol containing 2 mmol/L ammonium acetate and 0.1% (v/v) formic acid was used to wash the column. The retention times were 1.4 min for citrate and 1.4 min for d4-citrate. Cycle time was 4.0 min, injection to injection. The analytes were monitored using a tandem mass spectrometer operated in multiple reaction monitoring mode using the following transitions, citrate m/ z 191.0> 111.0 and d4-citrate m/ z 195.0> 113.0.

Results: Within and between-batch coefficients of variation were <3% over the range 480-3800 µmol/L. The lower limit of quantification was 24.0 µmol/L. Regression analysis showed LC-MS/MS = 0.8781 (enzymatic assay) + 102.5, r = 0.964, n = 73.

Conclusions: We have developed a simple LC-MS/MS method for urinary citrate measurement that shows acceptable performance.

Specific variations in the protocol for the induction of collagen-induced arthritis in mice improve reproducibility of disease severity and incidence in an SPF facility (BA6P.136)

Collagen-induced arthritis (CIA) is a widely used model for studying inflammatory arthritis (IA). CIA incidence and severity (I&S) varies between labs. Factors effecting induction include; adjuvant, # of collagen type II (CII) immunizations (imm), use of LPS and environmental hygiene. A better understanding of the effects of variations in protocols/environment on the I&S of CIA would improve the quality use this model. Method: Mice in conventional (con) and specific-pathogen free (SPF) facilities were compared. Mice were imm with 2 doses CII in complete (CFA) or incomplete (IFA) Freund’s adjuvant. LPS and/or CII were given at specific intervals following the 2nd imm. IA was evaluted using established scoring systems. Result: Following CII/CFA imm, con-housed had higher I&S of IA than SPF-housed mice. For SPF-housed mice, LPS 3 d after the 2nd CII/CFA imm modestly increased IA I&S. Unlike LPS or CII alone, additional LPS+CII 14 and 28 d later resulted in severe IA in all mice. Substitution of IFA for CFA along with LPS/CII at 14 and 28 d allowed for development of moderately severe IA in 80% of mice. Conclusion: Specific variations in use of CII, CFA, IFA and LPS can induce a range of IA I&S in a SPF facility . Thus, distinct experimental settings may be designed for robust assessment of factors that either exacerbate or inhibit arthritis pathogenesis. These protocols provide a practical and humane benefit of reducing cost, time and mice necessary for experimental assessment.

Plasminogen is a joint-specific positive or negative determinant of arthritis pathogenesis in mice

OBJECTIVE

A fundamental metric in the diagnosis of arthropathies is the pattern of joint involvement, including differences in proximal versus distal joints and patterns of symmetric or asymmetric disease. The basis for joint selectivity among arthritides and/or within a defined disease such as rheumatoid arthritis remains enigmatic. Coagulation and fibrinolytic activity are observed in both experimental animals with inflammatory joint disease and patients with inflammatory arthritis. However, the contribution of specific hemostatic factors to joint disease is not fully defined. We sought to determine the contribution of the fibrinolytic protease, plasminogen, to tumor necrosis factor α (TNFα)-driven arthritis in distinct joints in mice.

METHODS

The impact of plasminogen and/or fibrinogen genetic deficiencies on arthritis progression was evaluated in Tg197 mice genetically predisposed to spontaneous, nonabating, and erosive polyarthritis due to exuberant human TNFα expression.

RESULTS

Elimination of plasminogen in Tg197 mice significantly exacerbated the incidence and severity of arthritis within the paw joints, but simultaneously and dramatically diminished the entire spectrum of pathologies within the knee joints of the same animals. These opposing outcomes were both mechanistically linked to fibrin(ogen), in that superimposing fibrinogen deficiency reversed both the proarthritic phenotype in the paws and arthritis resistance in the knees of plasminogen-deficient mice. Intriguingly, the change in disease severity in the knees, but not the paws, was associated with a plasminogen-dependent reduction in matrix metalloproteinase 9 activity.

CONCLUSION

Plasminogen is a key molecular determinant of inflammatory joint disease capable of simultaneously driving or ameliorating arthritis pathogenesis in distinct anatomic locations in the same subject.

In vivo optical imaging of brain tumors and arthritis using fluorescent SapC-DOPS nanovesicles

We describe a multi-angle rotational optical imaging (MAROI) system for in vivo monitoring of physiopathological processes labeled with a fluorescent marker. Mouse models (brain tumor and arthritis) were used to evaluate the usefulness of this method. Saposin C (SapC)-dioleoylphosphatidylserine (DOPS) nanovesicles tagged with CellVue Maroon (CVM) fluorophore were administered intravenously. Animals were then placed in the rotational holder (MARS) of the in vivo imaging system. Images were acquired in 10° steps over 380°. A rectangular region of interest (ROI) was placed across the full image width at the model disease site. Within the ROI, and for every image, mean fluorescence intensity was computed after background subtraction. In the mouse models studied, the labeled nanovesicles were taken up in both the orthotopic and transgenic brain tumors, and in the arthritic sites (toes and ankles). Curve analysis of the multi angle image ROIs determined the angle with the highest signal. Thus, the optimal angle for imaging each disease site was characterized. The MAROI method applied to imaging of fluorescent compounds is a noninvasive, economical, and precise tool for in vivo quantitative analysis of the disease states in the described mouse models.

Screening for HIV-related neurocognitive impairment in clinical practice: challenges and opportunities

With increasingly successful management of HIV, focus has shifted away from AIDS-related complications to other chronic co-morbidities. For HIV-related cognitive problems, the true aetiopathogenesis and epidemiology remains unclear. Rather than a systematic review, this paper presents the challenges and the opportunities we faced in establishing our own clinical service. Papers were identified using Pubmed and the terms "screening", "HIV" and "neurocognitive". This article covers the background of HIV-associated neurocognitive disorders (HAND) with a focus on HIV-related neurocognitive impairment (NCI), detailing classification, prevalence, diagnostic categories and diagnostic uncertainties. Screening is discussed, including a comparison of the available screening tools for cognitive deficits in HIV-infected patients and the importance of practice effects. Discussed also are the normal ranges and the lack thereof and potential investigations for those found to have impairments. We conclude by discussing the role of NCI screening in routine clinical care at the current time.

Systemic delivery of SapC-DOPS has antiangiogenic and antitumor effects against glioblastoma

Saposin C-dioleoylphosphatidylserine (SapC-DOPS) nanovesicles are a nanotherapeutic which effectively target and destroy cancer cells. Here, we explore the systemic use of SapC-DOPS in several models of brain cancer, including glioblastoma multiforme (GBM), and the molecular mechanism behind its tumor-selective targeting specificity. Using two validated spontaneous brain tumor models, we demonstrate the ability of SapC-DOPS to selectively and effectively cross the blood-brain tumor barrier (BBTB) to target brain tumors in vivo and reveal the targeting to be contingent on the exposure of the anionic phospholipid phosphatidylserine (PtdSer). Increased cell surface expression of PtdSer levels was found to correlate with SapC-DOPS-induced killing efficacy, and tumor targeting in vivo was inhibited by blocking PtdSer exposed on cells. Apart from cancer cell killing, SapC-DOPS also exerted a strong antiangiogenic activity in vitro and in vivo. Interestingly, unlike traditional chemotherapy, hypoxic cells were sensitized to SapC-DOPS-mediated killing. This study emphasizes the importance of PtdSer exposure for SapC-DOPS targeting and supports the further development of SapC-DOPS as a novel antitumor and antiangiogenic agent for brain tumors.

The limited role of interferon-γ in systemic juvenile idiopathic arthritis cannot be explained by cellular hyporesponsiveness

OBJECTIVE

Systemic juvenile idiopathic arthritis (JIA) is an autoinflammatory syndrome in which the myelomonocytic lineage appears to play a pivotal role. Inflammatory macrophages are driven by interferon-γ (IFNγ), but studies have failed to demonstrate an IFN- induced gene signature in active systemic JIA. This study sought to characterize the status of an IFN-induced signature within affected tissue and to gauge the integrity of IFN signaling pathways within peripheral monocytes from patients with systemic JIA.

METHODS

Synovial tissue from 12 patients with active systemic JIA and 9 with active extended oligoarticular JIA was assessed by real-time polymerase chain reaction to quantify IFN-induced chemokine gene expression. Peripheral monocytes from 3 patients with inactive systemic JIA receiving anti-interleukin-1β (anti-IL-1β) therapy, 5 patients with active systemic JIA, and 8 healthy controls were incubated with or without IFNγ to gauge changes in gene expression and to measure phosphorylated STAT-1 (pSTAT-1) levels.

RESULTS

IFN-induced chemokine gene expression in synovium was constrained in active systemic JIA compared to the known IFN-mediated extended oligoarticular subtype. In unstimulated peripheral monocytes, IFN-induced gene expression was similar between the groups, except that lower levels of STAT1, MIG, and PIAS were observed in patients with active disease, while higher levels of PIAS1 were observed in patients with inactive disease. Basal pSTAT-1 levels in monocytes tended to be higher in systemic JIA patients compared to healthy controls, with the highest levels seen in those with inactive disease. Upon stimulation of monocytes, the fold increase in gene expression was roughly equal between groups, except for a greater increase in STAT1 in patients with inactive systemic JIA compared to controls, and a greater increase in IRF1 in those with active compared to inactive disease. Upon stimulation, the fold increase in pSTAT-1 was highest in monocytes from patients with inactive systemic JIA.

CONCLUSION

Monocytes in patients with active systemic JIA retain the ability to respond to IFNγ, suggesting that the lack of an IFN-induced gene signature in patients with active disease reflects a limited in vivo exposure to IFNγ. In patients with inactive systemic JIA who received treatment with anti-IL-1β, hyperresponsiveness to IFNγ was observed.

Recombinant adeno-associated virus preferentially transduces human, compared to mouse, synovium: implications for arthritis therapy

Despite a number of published reports, including from our own laboratory, suggesting that adeno-associated virus (AAV) transduces mouse synovium, a careful analysis demonstrated transduction predominantly of the subsynovial muscle tissue, while the synovial lining is poorly transduced. To investigate the potential of AAV to transduce human synovium, three human rheumatoid arthritis (RA) and two murine collagen-induced arthritis (CIA) synovial cell lines were infected with recombinant AAV (rAAV) vectors encoding either mouse IL-10 or IL-4. Low-level transgene expression was observed. However, either Gamma-irradiation or the addition of a low-titer E1-, E3-deleted recombinant adenovirus resulted in up to a 100-fold increase in transgene product in the human, but not the mouse, cell lines. RA synovial tissues implanted subcutaneously in severe combined immunodeficiency (SCID) mice, which were subsequently infected with rAAV, showed marked increases in transgene expression when co-infected with adenovirus. To our knowledge, this is the first study to show that intact human synovial tissues can be transduced by rAAV, and it suggests that murine arthritis may not be an optimal model to study rAAV as a gene transfer vector. Further studies to elucidate the mechanisms limiting gene transduction in human synovium may allow optimization of this vector for the treatment of arthritis.

Saposin C coupled lipid nanovesicles specifically target arthritic mouse joints for optical imaging of disease severity

Rheumatoid arthritis is a chronic inflammatory disease affecting approximately 1% of the population and is characterized by cartilage and bone destruction ultimately leading to loss of joint function. Early detection and intervention of disease provides the best hope for successful treatment and preservation of joint mobility and function. Reliable and non-invasive techniques that accurately measure arthritic disease onset and progression are lacking. We recently developed a novel agent, SapC-DOPS, which is composed of the membrane-associated lysosomal protein saposin C (SapC) incorporated into 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) lipid nanovesicles. SapC-DOPS has a high fusogenic affinity for phosphatidylserine-enriched microdomains on surfaces of target cell membranes. Incorporation of a far-red fluorophore, CellVue Maroon (CVM), into the nanovesicles allows for in vivo non-invasive visualization of the agent in targeted tissue. Given that phosphatidylserine is present only on the inner leaflet of healthy plasma membranes but is “flipped” to the outer leaflet upon cell damage, we hypothesized that SapC-DOPS would target tissue damage associated with inflammatory arthritis due to local surface-exposure of phosphatidylserine. Optical imaging with SapC-DOPS-CVM in two distinct models of arthritis, serum-transfer arthritis (e.g., K/BxN) and collagen-induced arthritis (CIA) revealed robust SapC-DOPS-CVM specific localization to arthritic paws and joints in live animals. Importantly, intensity of localized fluorescent signal correlated with macroscopic arthritic disease severity and increased with disease progression. Flow cytometry of cells extracted from arthritic joints demonstrated that SapC-DOPS-CVM localized to an average of 7–8% of total joint cells and primarily to CD11b+Gr-1+ cells. Results from the current studies strongly support the application of SapC-DOPS-CVM for advanced clinical and research applications including: detecting early arthritis onset, assessing disease progression real-time in live subjects, and providing novel information regarding cell types that may mediate arthritis progression within joints.

Gene expression signatures in polyarticular juvenile idiopathic arthritis demonstrate disease heterogeneity and offer a molecular classification of disease subsets

OBJECTIVE

To determine whether peripheral blood mononuclear cells (PBMCs) from children with recent-onset polyarticular juvenile idiopathic arthritis (JIA) exhibit biologically or clinically informative gene expression signatures.

METHODS

Peripheral blood samples were obtained from 59 healthy children and 61 children with polyarticular JIA prior to treatment with second-line medications, such as methotrexate or biologic agents. RNA was extracted from isolated mononuclear cells, fluorescence labeled, and hybridized to commercial gene expression microarrays (Affymetrix HG-U133 Plus 2.0). Data were analyzed using analysis of variance at a 5% false discovery rate threshold after robust multichip analysis preprocessing and distance-weighted discrimination normalization.

RESULTS

Initial analysis revealed 873 probe sets for genes that were differentially expressed between polyarticular JIA patients and healthy controls. Hierarchical clustering of these probe sets distinguished 3 subgroups within the polyarticular JIA group. Prototypical patients within each subgroup were identified and used to define subgroup-specific gene expression signatures. One of these signatures was associated with monocyte markers, another with transforming growth factor beta-inducible genes, and a third with immediate early genes. Correlation of gene expression signatures with clinical and biologic features of JIA subgroups suggested relevance to aspects of disease activity and supported the division of polyarticular JIA into distinct subsets.

CONCLUSION

Gene expression signatures in PBMCs from patients with recent-onset polyarticular JIA reflect discrete disease processes and offer a molecular classification of disease.