OP0231 MASS CYTOMETRY DATA RECLASSIFY SYSTEMIC AUTOIMMUNE DISEASE PATIENTS IN PHENOTYPICALLY DISTINCTIVE GROUPS

Background

Systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSC), Sjögren’s syndrome (SJS), mixed connective tissue disease (MCTD), primary antiphospholipid syndrome (PAPS) and undifferentiated connective tissue disease (UCTD) are classified as systemic autoimmune diseases (SADs). They are diagnosed based on different clinical and laboratory criteria. Due to their high internal heterogeneity and overlapping symptoms, SADs are difficult to diagnose. Therefore, molecular and cellular-based studies need to be undertaken to precisely classify the patients. Mass cytometry is a single-cell proteomics technology that measures approximately 50 markers per cell, thus it is a suitable tool to perform deep-phenotyping studies in SADs.

Objectives

Explore differences and similarities between SADs and build reclassification framework using high-dimensional cytometry data.

Methods

The whole blood samples collected from 129 individuals, including patients and controls were stained with a 39-plex antibody panel and acquired in 9 batches on a CyTOF (HELIOS) instrument. Data were cleaned, and normalized for batch effects using semi-automated cytof analysis pipeline. Cell frequencies and median signal intensities (MSI) for each population were extracted using FlowSOM for mononuclear cells (PBMC) and Phenograph for granulocytes. Secretion of 44 cytokines and chemokines were analyzed using a multiplexed luminex assay. Diseases were compared by Kruskal-Wallis analysis and hierarchical clustering and reclassification was done using unsupervised k-means clustering. Cytokine analysis across clusters was performed using Kruskal-Wallis test.

Results

Differently expressed features were observed between patient groups, regarding frequency of classical monocytes, B and T cells subpopulations, mature and immature granulocytes and intensities of CD38, HLA-DR and CD95 across various populations. However, none of them were disease specific. K-means clustering identified four patient clusters, which were composed by a mixture of different diagnosis. Cluster C1 was characterized by increased levels of circulating cells from PBMC compartment, and lower activation of different populations of the T cell compartment. It presented lower frequency in multiple granulocyte populations and the highest expression of CD95 and CD38. This cluster was also associated with antimalarial and steroid treatment. Clusters C1 and C2 were exactly opposite to each other, cluster C3 was characterized by intermediate features between C1 and C2 and cluster C4 could be considered as undifferentiated, mixed group. Higher production of TNFα, IL-10 and IP-10 were found in patients from C1 compared to C2, suggesting more active phenotype in C1 and physiological one in C2. The cytokine levels were independent of the treatment.

Conclusion

We constructed a patient reclassification framework using cell frequencies and expression levels of functional markers. To our knowledge this is the first time when 7 different SADs were compared using mass cytometry. In agreement with other reports we did not detect any disease-specific cellular markers. Distribution of diagnosis across different clusters confirms diseases heterogeneity. Patients can be classified into phenotypically similar groups, that could potentially benefit from the same line of treatment.

Acknowledgements

This project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking (JU) under grant agreement No 831434 (3TR) and The JU receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA. Also from No 115565 PRECISESADS.

Disclosure of Interests

None declared

SIDT1 plays a key role in type I IFN responses to nucleic acids in plasmacytoid dendritic cells and mediates the pathogenesis of an imiquimod-induced psoriasis model

Background

Type I IFN (IFN-I) is a family of cytokines involved in the pathogenesis of autoimmune and autoinflammatory diseases such as psoriasis. SIDT1 is an ER-resident protein expressed in the lymphoid lineage, and involved in anti-viral IFN-I responses in vivo, through an unclear mechanism. Herein we have dissected the role of SIDT1 in the natural IFN-producing cells, the plasmacytoid dendritic cells (pDC).

Methods

The function of SIDT1 in pDC was determined by silencing its expression in human primary pDC and GEN2.2 cell line. SIDT1 role in vivo was assessed using the imiquimod-induced psoriasis model in the SIDT1-deficient mice (sidt1^−/−).

Findings

Silencing of SIDT1 in GEN2.2 led to a blockade of the IFN-I response after stimulation of TLR7 and TLR9, without affecting the pro-inflammatory responses or upregulation of maturation markers. We found that SIDT1 migrates from the ER to the endosomal and lysosomal compartments together with TLR9 after CpG stimulation, participating in the access of the TLR9-CpG complex to lysosome-related vesicles, and therefore mediating the activation of TBK1 and the nuclear migration of IRF7, but not of NF-κB. sidt1^−/− mice showed a significant decrease in severity parameters of the imiquimod-induced acute psoriasis-like model, associated with a decrease in the production of IFN-I and IFN-dependent chemokines.

Interpretation

Our findings indicate that SIDT1 is at the cross-road between the IFN-I and the proinflammatory pathways and constitutes a promising drug target for psoriasis and other diseases mediated by IFN-I responses.

Funding

This work was supported by the Consejería de Salud y Familias de la Junta de Andalucía (PIER_S1149 and C2_S0050) and Instituto de Salud Carlos III (PI18/00082 and PI21/01151), partly supported by European FEDER funds, and prior funding to MEAR from the Alliance for Lupus Research and the Swedish Research Council.

Integrative Analysis Reveals a Molecular Stratification of Systemic Autoimmune Diseases

OBJECTIVE

Clinical heterogeneity, a hallmark of systemic autoimmune diseases, impedes early diagnosis and effective treatment, issues that may be addressed if patients could be classified into groups defined by molecular pattern. This study was undertaken to identify molecular clusters for reclassifying systemic autoimmune diseases independently of clinical diagnosis.

METHODS

Unsupervised clustering of integrated whole blood transcriptome and methylome cross-sectional data on 955 patients with 7 systemic autoimmune diseases and 267 healthy controls was undertaken. In addition, an inception cohort was prospectively followed up for 6 or 14 months to validate the results and analyze whether or not cluster assignment changed over time.

RESULTS

Four clusters were identified and validated. Three were pathologic, representing "inflammatory," "lymphoid," and "interferon" patterns. Each included all diagnoses and was defined by genetic, clinical, serologic, and cellular features. A fourth cluster with no specific molecular pattern was associated with low disease activity and included healthy controls. A longitudinal and independent inception cohort showed a relapse-remission pattern, where patients remained in their pathologic cluster, moving only to the healthy one, thus showing that the molecular clusters remained stable over time and that single pathogenic molecular signatures characterized each individual patient.

CONCLUSION

Patients with systemic autoimmune diseases can be jointly stratified into 3 stable disease clusters with specific molecular patterns differentiating different molecular disease mechanisms. These results have important implications for future clinical trials and the study of nonresponse to therapy, marking a paradigm shift in our view of systemic autoimmune diseases.

Stabilization of Human Whole Blood Samples for Multicenter and Retrospective Immunophenotyping Studies

Whole blood is often collected for large-scale immune monitoring studies to track changes in cell frequencies and responses using flow (FC) or mass cytometry (MC). In order to preserve sample composition and phenotype, blood samples should be analyzed within 24 h after bleeding, restricting the recruitment, analysis protocols, as well as biobanking. Herein, we have evaluated two whole blood preservation protocols that allow rapid sample processing and long-term stability. Two fixation buffers were used, Phosphoflow Fix and Lyse (BD) and Proteomic Stabilizer (PROT) to fix and freeze whole blood samples for up to 6 months. After analysis by an 8-plex panel by FC and a 26-plex panel by MC, manual gating of circulating leukocyte populations and cytokines was performed. Additionally, we tested the stability of a single sample over a 13-months period using 45 consecutive aliquots and a 34-plex panel by MC. We observed high correlation and low bias toward any cell population when comparing fresh and 6 months frozen blood with FC and MC. This correlation was confirmed by hierarchical clustering. Low coefficients of variation (CV) across studied time points indicate good sample preservation for up to 6 months. Cytokine detection stability was confirmed by low CVs, with some differences between fresh and fixed conditions. Thirteen months regular follow-up of PROT samples showed remarkable sample stability. Whole blood can be preserved for phenotyping and cytokine-response studies provided the careful selection of a compatible antibody panel. However, possible changes in cell morphology, differences in antibody affinity, and changes in cytokine-positive cell frequencies when compared to fresh blood should be considered. Our setting constitutes a valuable tool for multicentric and retrospective studies. © 2020 International Society for Advancement of Cytometry.

Metagene projection characterizes GEN2.2 and CAL-1 as relevant human plasmacytoid dendritic cell models

Motivation

Plasmacytoid dendritic cells (pDC) play a major role in the regulation of adaptive and innate immunity. Human pDC are difficult to isolate from peripheral blood and do not survive in culture making the study of their biology challenging. Recently, two leukemic counterparts of pDC, CAL-1 and GEN2.2, have been proposed as representative models of human pDC. Nevertheless, their relationship with pDC has been established only by means of particular functional and phenotypic similarities. With the aim of characterizing GEN2.2 and CAL-1 in the context of the main circulating immune cell populations we have performed microarray gene expression profiling of GEN2.2 and carried out an integrated analysis using publicly available gene expression datasets of CAL-1 and the main circulating primary leukocyte lineages.

Results

Our results show that GEN2.2 and CAL-1 share common gene expression programs with primary pDC, clustering apart from the rest of circulating hematopoietic lineages. We have also identified common differentially expressed genes that can be relevant in pDC biology. In addition, we have revealed the common and differential pathways activated in primary pDC and cell lines upon CpG stimulatio.

Availability and implementation

R code and data are available in the supplementary material.

Contact

pedro.carmona@genyo.es or concepcion.maranon@genyo.es.

Supplementary information

Supplementary data are available at Bioinformatics online.

[Control of cardiovascular risk factors in type 2 diabetes in a specialized diabetic clinic]

BACKGROUND

Achieving an adequate control of glycaemic and cardiovascular risk factors (CVRFs) is essential in patients with type 2 diabetes mellitus (T2DM). However, several studies have shown that the percentage of patients achieving these goals is scarce. We evaluated the degree of control of CVRFs target goals in T2DM patients who regularly attend a specialized diabetic clinic.

METHODS

We studied T2DM patients who attended the specialized Diabetic Unit at the Department of Endocrinology of Clínica Universitaria de Navarra with a minimum follow-up of one year. Clinical characteristics, chronic complications and treatments were collected and patients were classified into groups according to the fulfilment of target glycated haemoglobin (HbA1c), LDL cholesterol and blood pressure (BP) levels, predefined according to the presence of different comorbidities and the duration of T2DM.

RESULTS

We analysed 137 patients (75% men) with T2DM, with an average age of 67 years and a 12.7 year duration of diabetes. During follow-up, 83.9% of the patients were within the individualized HbA1c target, 76.6% considering BP and 67.2% in terms of LDL-cholesterol. In addition, 68% had concomitantly the three main variables within the target.

CONCLUSIONS

In our population of T2DM, HbA1c, LDL cholesterol and BP targets were achieved in a substantial proportion of patients (67-91%). Perhaps the intense and individualized care offered through a specialized diabetes unit may explain these results.

[Assessment of the impact of pain on work productivity: validation of the Spanish WPAI:Pain questionnaire]

BACKGROUND

Health measuring instruments are essential in daily clinical practice. However, a validation process is needed in order to certify the validity and reliability of it. The aim of our study is to validate a questionnaire to assess the consequences of pain in work productivity.

METHODS

Based on the Work Productivity and Activity Impairment Questionnaire – General Health we have created a modified version called WPAI:Pain in order to be able to measure the consequences of pain in work productivity. The study was conducted following the usual guidelines of test validation, omitting face validity as WPAI:Pain is a modification of an existing questionnaire. Validity and reliability were calculated.

RESULTS

A total of 577 questionnaires were obtained in 2 spanish university hospitals. The questionnaire's discriminating power was verified by Mann-Whitney test. Reliability tests were realized, Cronbach's alpha was 0.896 and Guttman split-half was 0.921. Stability was evaluated with a test-retest which was significant. Construct validity was established by Pearson correlation comparing the results of the questionnaire with the pain visual analog scale, which was statistically significant for all values.

CONCLUSIONS

The WPAI:Pain questionnaire is a valid instrument for measuring the consequences of pain in work productivity.It is currently the only one validated in Spanish.Major studies are needed in order to establish its universal validity.

Transversus abdominal plane block as a sole anesthetic technique for abdominal wall hematoma drainage

Transversus abdominal plane (TAP) block is a known and useful technique, widely used for postoperative pain management of abdominal wall incisions. During the past years, and following the expansion of ultrasound guided techniques, its use has even gained more adepts. It is usually used as an adjuvant technique, primarily in order to control postoperative pain and reduce opioids consumption. We report the case of an 82 years old patient admitted for drainage of a postoperative abdominal wall hematoma after correction of a McBurney incisional hernia. The corrective surgery had gone on without incident, under general anesthesia with laryngeal mask. Two weeks later, the patient came back to our emergency department with a clear hematoma of the abdominal wall. Surgery was decided. A sole local anesthetic technique was achieved, using a TAP block. The block was performed under ultrasound guidance, using a subcostal approach. The surgery went on without complications. Therefore, TAP block offers a hemodynamic stability, appropriate intra-operative anesthesia and post-surgical analgesia of the abdominal wall.

Concordance of increased B1 cell subset and lupus phenotypes in mice and humans is dependent on BLK expression levels

Polymorphisms in the B lymphoid tyrosine kinase (BLK) gene have been associated with autoimmune diseases, including systemic lupus erythematosus, with risk correlating with reduced expression of BLK. How reduced expression of BLK causes autoimmunity is unknown. Using Blk(+/+) , Blk(+/-) , and Blk(-/-) mice, we show that aged female Blk(+/-) and Blk(-/-) mice produced higher anti-dsDNA IgG Abs and developed immune complex-mediated glomerulonephritis, compared with Blk(+/+) mice. Starting at young age, Blk(+/-) and Blk(-/-) mice accumulated increased numbers of splenic B1a cells, which differentiated into class-switched CD138(+) IgG-secreting B1a cells. Increased infiltration of B1a-like cells into the kidneys was also observed in aged Blk(+/-) and Blk(-/-) mice. In humans, we found that healthy individuals had BLK genotype-dependent levels of anti-dsDNA IgG Abs as well as increased numbers of a B1-like cell population, CD19(+)CD3(-)CD20(+)CD43(+)CD27(+), in peripheral blood. Furthermore, we describe the presence of B1-like cells in the tubulointerstitial space of human lupus kidney biopsies. Taken together, our study reveals a previously unappreciated role of reduced BLK expression on extraperitoneal accumulation of B1a cells in mice, as well as the presence of IgG autoantibodies and B1-like cells in humans.

Concordance of increased B1 cell subset and lupus phenotypes in mouse and human dependent on BLK expression genotypes (BA3P.114)

Polymorphisms in the BLK gene have been associated with autoimmune diseases, including systemic lupus erythematosus (SLE), with risk correlating with reduced expression of BLK. How reduced expression of BLK causes autoimmunity is unknown. Using Blk+/+, Blk+/-, and Blk-/- mice, we show that aged female Blk+/- and Blk-/- mice produced higher anti-dsDNA IgG antibodies and developed immune complex-mediated glomerulonephritis, compared to Blk+/+ mice. Starting at young age, Blk+/- and Blk-/- mice accumulated increased numbers of splenic B1a cells, which differentiated into class-switched CD138+IgG-secreting B1a cells. Increased infiltration of B1a-enriched cells into the kidneys was also observed in aged Blk+/- and Blk-/- mice. In human, we found that healthy individuals had BLK genotype-dependent levels of anti-dsDNA IgG antibodies as well as increased numbers of a B1-like cell population, CD19+CD3-CD20+CD43+CD27+, in peripheral blood. Furthermore, we describe the presence of B1-like cells in the tubulointerstitial space of human lupus kidney biopsies. Taken together, our study reveals a previously unappreciated role of reduced BLK expression on extraperitoneal accumulation of B1a cells in mice, and the presence of IgG autoantibodies and B1-like cells in human.

Bioequivalence of acenocoumarol in chilean volunteers: an open, randomized, double-blind, single-dose, 2-period, and 2-sequence crossover study for 2 oral formulations

The aim of this study was to compare the bioavailability of an oral formulation of the coumarin derivative-vitamine K antagonist acenocoumarol (Acebron™ 4 mg, Test) with the reference formulation (Neo-Sintrom™ 4 mg). We performed a single-dose, double-blind, fasting, 2-period, 2-sequence, crossover study design. Plasma concentrations of acenocoumarol were determined using a validated UPLC-MS/MS method. 24 healthy Chilean volunteers (11 male, 13 female) were enrolled and all of them completed the study. Adverse events were monitored throughout the study. The values of the pharmacokinetic parameters were (mean ± SD): AUC0-24 =1 364.38±499.26 ngxh/mL for the test and 1 328.39±429.20 ngxh/mL for the reference; AUC0-∞ =1 786.00±732.85 ngxh/mL for the test and 1 706.71±599.66 ngxh/mL for the reference; Cmax =180.69±35.11 ng/mL with a Tmax of 1.83±0.95 h for the test and 186.97±38.21 ng/mL with a Tmax of 2.19±0.83 h for the reference. Regarding half life measurements, the mean ± SD of t1/2 were 11.84±4.54 h for the test and 11.08±3.28 h for the reference. The 90% confidence intervals for the test/reference ratio using logarithmic transformed data were 97.89-100.87%, 98.62-101.99% and 98.64-102.38% for Cmax, AUC0-t(24) and AUC0-∞. There were no significant differences in pharmacokinetic parameters between groups.The results obtained in this study lead us to conclude, based on FDA criteria, that the test acenocoumarol formulation (Acebron™, 4 mg tablets) is bioequivalent to the reference product (Neo-Sintrom™, 4 mg tablets).

Human adipose-derived mesenchymal stem cells reduce inflammatory and T cell responses and induce regulatory T cells in vitro in rheumatoid arthritis

OBJECTIVES

Adult mesenchymal stem cells were recently found to suppress effector T cell and inflammatory responses and have emerged as attractive therapeutic candidates for immune disorders. In rheumatoid arthritis (RA), a loss in the immunological self-tolerance causes the activation of autoreactive T cells against joint components and subsequent chronic inflammation. The aim of this study is to characterise the immunosuppressive activity of human adipose-derived mesenchymal stem cells (hASCs) on collagen-reactive T cells from patients with RA.

METHODS

The effects of hASCs on collagen-reactive RA human T cell proliferation and cytokine production were investigated, as well as effects on the production of inflammatory mediators by monocytes and fibroblast-like synoviocytes from patients with RA.

RESULTS

hASCs suppressed the antigen-specific response of T cells from patients with RA. hASCs inhibited the proliferative response and the production of inflammatory cytokines by collagen-activated CD4 and CD8 T cells. In contrast, the numbers of IL10-producing T cells and monocytes were significantly augmented upon hASC treatment. The suppressive activity of hASCs was cell-to-cell contact dependent and independent. hASCs also stimulated the generation of FoxP3 protein-expressing CD4(+)CD25(+) regulatory T cells, with the capacity to suppress collagen-specific T cell responses. Finally, hASCs downregulated the inflammatory response and the production of matrix-degrading enzymes by synovial cells isolated from patients with RA.

CONCLUSIONS

The present work identifies hASCs as key regulators of immune tolerance, with the capacity to suppress T cell and inflammatory responses and to induce the generation/activation of antigen-specific regulatory T cells.

Genetic association of vasoactive intestinal peptide receptor with rheumatoid arthritis: altered expression and signal in immune cells

OBJECTIVE

Vasoactive intestinal peptide (VIP) has been shown to be one of the endogenous factors involved in the maintenance of immune tolerance. Administration of VIP ameliorates clinical signs in various experimental autoimmune disorders. This study was undertaken to investigate whether the exacerbated inflammatory autoimmune response in rheumatoid arthritis (RA) might result directly from altered expression and/or signaling of VIP receptors in immune cells.

METHODS

The effect of specific agonists of different VIP receptors on collagen-induced arthritis in mice was investigated by clinical and histologic assessment and measurement of cytokine and chemokine production. Expression of VIP receptor type 1 (VPAC1) in synovial cells and monocytes from RA patients was determined by flow cytometry. Potential associations of VPAC1 genetic polymorphisms with RA susceptibility were investigated.

RESULTS

A VPAC1 agonist was very efficient in the treatment of experimental arthritis, and deficient expression of VPAC1 in immune cells of RA patients was associated with the predominant proinflammatory Th1 milieu found in this disease. Immune cells derived from RA patients were less responsive to VIP signaling than were cells from healthy individuals and showed reduced VIP-mediated immunosuppressive activity, rendering leukocytes and synovial cells more proinflammatory in RA. A significant association between multiple-marker haplotypes of VPAC1 and susceptibility to RA was found, suggesting that the reduced VPAC1 expression in RA-derived immune cells is associated with the described VPAC1 genetic polymorphism.

CONCLUSION

These findings are highly relevant to the understanding of RA pathogenesis. They suggest that VIP signaling through VPAC1 is critical to maintaining immune tolerance in RA. In addition, the results indicate that VPAC1 may be a novel therapeutic target in RA.

Therapeutical approaches of vasoactive intestinal peptide as a pleiotropic immunomodulator

The vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) are two neuropeptides belonging to the VIP/secretin/glucagon family of peptides. VIP/PACAP are present and released from both innervation and immune cells, particularly Th2 cells, and exert a wide spectrum of immunological functions controlling the homeostasis of immune system through different receptors expressed in various immunocompetent cells. VIP/PACAP have a general anti-inflammatory effect, both in innate and adaptive immunity. In innate immunity, VIP/PACAP inhibit the production of pro-inflammatory cytokines and chemokines from macrophages, microglia and dendritic cells. In addition, VIP/PACAP reduce the expression of costimulatory molecules (particularly CD80 and CD86) on the antigen-presenting cells, and therefore reduce stimulation of antigen-specific CD4(+) T cells. In terms of adaptive immunity, VIP/PACAP promote Th2-type responses, and reduce the pro-inflammatory Th1-type responses. Several of the molecular mechanisms involved in the inhibition of cytokine and chemokine expression, and in the preferential development and/or survival of Th2 effectors, are perfectly known. Therefore, VIP/PACAP and analogues have been recently proposed as very promising candidates, alternative to other existing treatments, for treating acute and chronic inflammatory and autoimmune diseases, such as septic shock, rheumatoid arthritis, multiple sclerosis, Parkinson's disease, Crohn disease, or autoimmune diabetes. The aim of this review is firstly to update our knowledge of the cellular and molecular events relevant to VIP function on the immune system; and secondly to gather together recent data that support its role as a type 2 cytokine. Recognition of the central functions VIP plays in cellular processes is focusing our attention on this "very important peptide" as an exciting new candidate for therapeutic intervention and drug development.

Tuning inflammation with anti-inflammatory neuropeptides

The immune system is confronted with the daunting task of defending the organism against invading pathogens while at the same time remaining self-tolerant to the body's own constituents and preserving its integrity. The loss of immune tolerance stemming from an unbalance in pro-inflammatory factors versus anti-inflammatory cytokines, or of autoreactive/inflammatory T helper 1 cells versus regulatory/suppressive T cells, results in the breakdown of immune homeostasis and the subsidiary appearance of exacerbated inflammatory and autoimmune diseases. Some neuropeptides have been shown to have anti-inflammatory properties and to participate in maintaining immune tolerance. Here the authors examine the most recent developments in this field and highlight the effectiveness of using neuropeptides in treating several inflammatory and autoimmune disorders.

Therapeutic effect of urocortin on collagen-induced arthritis by down-regulation of inflammatory and Th1 responses and induction of regulatory T cells

OBJECTIVE

To investigate the potential therapeutic action of the immunomodulatory neuropeptide urocortin (UCN) in an experimental model of rheumatoid arthritis (RA).

METHODS

After disease onset, DBA/1J mice with collagen-induced arthritis (CIA) were treated with UCN, and the incidence, severity (clinical score), and joint histopathology were evaluated. The inflammatory response was determined by measuring the levels of different mediators of inflammation (cytokines and chemokines) in the joints and sera. The Th1-mediated autoreactive response was evaluated by determining the proliferative response and cytokine profile of draining lymph node cells stimulated with the autoantigen and by assaying the content of serum autoantibodies. The number of regulatory CD4+,CD25+ T cells and their capacity to suppress self-reactive Th1 cells were determined in joints and lymph nodes.

RESULTS

UCN treatment significantly reduced the incidence and severity of CIA, completely abrogating joint swelling and cartilage and bone destruction. The therapeutic effect of UCN was associated with a striking reduction of the 2 deleterious components of the disease: the Th1-driven autoimmune response and the inflammatory response. UCN also induced the generation and/or activation of efficient interleukin-10/transforming growth factor beta1-producing Treg cells in arthritis with the capacity to suppress the autoreactive response and to restore immune tolerance, thus playing a pivotal role in the therapeutic effect of UCN.

CONCLUSION

Our findings provide a powerful rationale for assessing the efficacy of UCN as a novel multistep therapeutic approach to the treatment of RA in humans.

Therapeutic effect of cortistatin on experimental arthritis by downregulating inflammatory and Th1 responses

BACKGROUND

Rheumatoid arthritis is a chronic autoimmune disease of unknown aetiology characterised by chronic inflammation in the joints and subsequent destruction of the cartilage and bone.

AIM

To propose a new strategy for the treatment of arthritis based on the administration of cortistatin, a newly discovered neuropeptide with anti-inflammatory actions.

METHODS

DBA/1J mice with collagen-induced arthritis were treated with cortistatin after the onset of disease, and the clinical score and joint histopathology were evaluated. Inflammatory response was determined by measuring the levels of various inflammatory mediators (cytokines and chemokines) in joints and serum. T helper cell type 1 (Th1)-mediated autoreactive response was evaluated by determining the proliferative response and cytokine profile of draining lymph node cells stimulated with collagen and by assaying the content of serum autoantibodies.

RESULTS

Cortistatin treatment significantly reduced the severity of established collagen-induced arthritis, completely abrogating joint swelling and destruction of cartilage and bone. The therapeutic effect of cortistatin was associated with a striking reduction in the two deleterious components of the disease-that is, the Th1-driven autoimmune and inflammatory responses. Cortistatin downregulated the production of various inflammatory cytokines and chemokines, decreased the antigen-specific Th1-cell expansion, and induced the production of regulatory cytokines, such as interleukin 10 and transforming growth factor beta1. Cortistatin exerted its effects on synovial cells through both somatostatin and ghrelin receptors, showing a higher effect than both peptides protecting against experimental arthritis.

CONCLUSION

This work provides a powerful rationale for the assessment of the efficacy of cortistatin as a novel therapeutic approach to the treatment of rheumatoid arthritis.

Urocortin and adrenomedullin prevent lethal endotoxemia by down-regulating the inflammatory response

Urocortin 1 (UCN) and adrenomedullin (AM) are two neuropeptides that have emerged as potential endogenous anti-inflammatory factors based on their production by and binding to immune cells. Because human septic shock involves excessive inflammatory cytokine production, we investigated the effect of UCN and AM in the production of inflammatory mediators and their therapeutic actions in two models of septic shock. Both peptides down-regulated the production of inflammatory mediators by endotoxin-activated macrophages. The administration of UCN or AM protected against lethality after cecal ligation and puncture or after injection of bacterial endotoxin and prevented septic shock-associated histopathology, such as infiltration of inflammatory cells and intravascularly disseminated coagulation in various target organs. The therapeutic effect of UCN and AM was mediated by decreasing the local and systemic levels of a wide spectrum of inflammatory mediators, including cytokines, chemokines, and the acute phase protein serum amyloid A. Importantly, UCN or AM treatment was therapeutically effective in established endotoxemia. In conclusion, UCN and AM could represent two multistep therapeutic agents for human septic shock to be used in combination with other immunomodulatory agents or complementary as anti-inflammatory factors to other therapies.

Cortistatin, an antiinflammatory peptide with therapeutic action in inflammatory bowel disease

Cortistatin is a recently discovered cyclic neuropeptide related to somatostatin that has emerged as a potential endogenous antiinflammatory factor based on its production by, and binding to, immune cells. Crohn's disease is a chronic debilitating disease characterized by severe T helper 1 (Th1)-driven inflammation of the gastrointestinal tract. The aim of this study is to investigate the therapeutic effect of cortistatin in a murine model of colitis. Cortistatin treatment significantly ameliorated the clinical and histopathologic severity of the inflammatory colitis, abrogating body weight loss, diarrhea, and inflammation and increased the survival rate of the colitic mice. The therapeutic effect was associated with down-regulation of inflammatory and Th1-driven autoimmune response, including the regulation of a wide spectrum of inflammatory mediators. In addition, a partial involvement of regulatory IL-10-secreting T cells in this therapeutic effect was demonstrated. Importantly, cortistatin treatment was therapeutically effective in established colitis and avoided the recurrence of the disease. This work identifies cortistatin as an antiinflammatory factor with the capacity to deactivate the intestinal inflammatory response and restore mucosal immune tolerance at multiple levels. Consequently, cortistatin represents a multistep therapeutic approach for the treatment of Crohn's disease and other Th1-mediated inflammatory diseases.

Vasoactive intestinal peptide family as a therapeutic target for Parkinson’s disease

Parkinson's disease (PD) is a common neurodegenerative disorder with no effective protective treatment, characterised by a massive degeneration of dopaminergic neurons in the substantia nigra and the subsequent loss of their projecting nerve fibres in the striatum. Because current treatments for PD are not effective, considerable research has been focused recently on a number of regulatory molecules that regulate inflammation characteristic of PD, induce neurotrophic and survival factors and reduce oxidative stress. Vasoactive intestinal peptide (VIP), a neuropeptide with a potent anti-inflammatory, antiapoptotic and neurotrophic effect, has been found to be protective in several inflammatory disorders. This review examines the putative protective effect of VIP and analogues in different models for PD. VIP emerges as a potential valuable neuroprotective agent for the treatment of pathological conditions in the CNS, such as PD, in which inflammation-induced neurodegeneration occurs.

CYP1A1, CYP2E1 and GSTM1 genetic polymorphisms. The effect of single and combined genotypes on lung cancer susceptibility in Chilean people

CYP1A1, CYP2E1 and GSTM1 polymorphisms were evaluated in Chilean healthy controls and lung cancer patients. In the Chilean healthy group, frequencies of CYP1A1 variant alleles for MspI (m2 or CYP1A1*2A) and ile/val (val or CYP1A1*2B) polymorphisms were 0.25 and 0.33, respectively. Frequencies of variant alleles C (CYP2E1*6) and c2 (CYP2E1*5B) for CYP2E1 were 0.21 and 0.16, respectively and frequency for GSTM1(-) was 0.24. The presence of variant alleles for GSTM1, MspI and Ile/val polymorphisms was more frequent in cases than in controls. However, frequencies for the c2 and C alleles were not significantly different in controls and in cases. The estimated relative risk for lung cancer associated to a single mutated allele in CYP1A1, CYP2E1 or GSTM1 was 2.41 for m2, 1.69 for val, 1.16 for C, 0.71 for c2 and 2.46 for GSTM1(-). The estimated relative risk was higher for individuals carrying combined CYP1A1 and GSTM1 mutated alleles (m2/val, OR=6.28; m2/GSTM1(-), OR=3.56) and lower in individuals carrying CYP1A1 and CYP2E1 mutated alleles (m2/C, OR=1.39; m2/c2, OR=2.00; val/C, OR=1.45; val/c2, OR=0.48; not significant). The OR values considering smoking were 4.37 for m2, 4.05 for val, 3.47 for GSTM1(-), 7.38 for m2/val and 3.68 for m2/GSTM1(-), higher values than those observed without any stratification by smoking. Taken together, these findings suggest that Chilean people carrying single or combined GSTM1 and CYP1A1 polymorphisms could be more susceptible to lung cancer induced by environmental pollutants such as polycyclic aromatic hydrocarbons.

Interferon-gamma sensitizes human myeloid leukemia cells to death receptor-mediated apoptosis by a pleiotropic mechanism

The role of interferon (IFN)-gamma as a sensitizing agent in apoptosis induced by ligation of death receptors has been evaluated in human myeloid leukemia cells. Incubation of U937 cells with IFN-gamma sensitized these cells to apoptosis induced by tumor necrosis factor-alpha, agonistic CD95 antibody, and tumor necrosis factor-related apoptosis-inducing ligand. Other human myeloid leukemic cells were also sensitized by IFN-gamma to death receptor-mediated apoptosis. Treatment of U937 cells with IFN-gamma up-regulated the expression of caspase-8 and potently synergized with death receptor ligation in the processing of caspase-8 and BID cleavage. Concomitantly, a marked down-regulation of BCL-2 protein was also observed in cells incubated with IFN-gamma. Furthermore, the caspase-dependent generation of a 23-kDa fragment of BCL-2 protein, the release of cytochrome c from mitochondria and the activation of caspase-9 were also enhanced upon death receptor ligation in IFN-gamma-treated cells. Ectopically expressed Bcl-2 protein inhibited IFN-gamma-induced sensitization to apoptosis. In summary, these results indicate that IFN-gamma sensitizes human myeloid leukemic cells to a death receptor-induced, mitochondria-mediated pathway of apoptosis.

Ethnic susceptibility to lung cancer: differences in CYP2E1, CYP1A1 and GSTM1 genetic polymorphisms between French Caucasian and Chilean populations

Many investigators have reported an association between genetic polymorphisms of cytochromes P-450 CYP2E1, CYP1A1 or glutathione S-transferase Mu (GSTM1) and susceptibility to lung cancer. However, pronounced interethnic variations have been described in the frequencies of these polymorphisms, especially between Asians and Caucasians. The present study was set up to establish CYP2E1 (c1, c2 and C, D), CYP1A1 (m1, m2 and Ile, Val) and GSTM1 (null) allelic frequencies in Chileans (n = 96) who are an admixture of Native Americans and Caucasians (Spaniards). The rare allele frequencies were found to be 0.15 (c2), 0.21 (C), 0.23 (m2), 0.32 (Val) and 0.21 ('null' genotype). These values are significantly higher than those of Caucasians except for the GSTM1 'null' genotype and suggest differences in susceptibility to lung cancer between both populations.

Interferon-alpha production and tissue localization of interferon-alpha/beta producing cells after intradermal administration of Aujeszky's disease virus-infected cells in pigs

Intradermal administration of glutaraldehyde-fixed Aujeszky's disease virus (ADV) infected autologous or allogeneic cells resulted in the induction of an interferon (IFN)-alpha response in pigs. Using a sensitive dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA), IFN-alpha was detected in blood at 8 and 24 h after injection of ADV-infected cells. In parallel, by means of in situ hybridization, IFN-alpha/beta mRNA containing cells were demonstrated in regional lymph nodes. Occasional IFN-alpha/beta mRNA positive cells were also seen in injected dermal areas, but not in contralateral lymph nodes, spleen, bone marrow, blood or liver. The ability of leucocytes in whole blood cultures to produce IFN-alpha upon stimulation by ADV was markedly diminished 3-7 days after intradermal injection of ADV-infected cells. In contrast, cultures of purified peripheral blood mononuclear cells (PBMC) had intact IFN-alpha responses. Further, serum from ADV-injected pigs inhibited the in vitro ADV-induced IFN-alpha responses in PBMC from control pigs, most likely due to the demonstrated presence of anti-ADV antibodies. We suggest that the IFN-alpha/beta producing cells in lymph nodes may participate in the development of antiviral immunity and could be equivalent to Natural IFN-alpha/beta producing (NIP) cells.