Giusi Barra

Evidence of the transient nature of the Th17 phenotype of CD4+CD161+ T cells in the synovial fluid of patients with juvenile idiopathic arthritis

OBJECTIVE To investigate the phenotype and function of CD4+ T cells in synovial fluid (SF) from the affected joints of children with oligoarticular-onset juvenile idiopathic arthritis (JIA), and to establish a possible link with disease activity. METHODS CD4+ T cells were obtained from the peripheral blood (PB) and SF of 23 children with oligoarticular-onset JIA, as well as from the PB of 15 healthy children. The cells were analyzed for the expression of CXCR3, CCR6, and CD161 and for the production of interferon-γ and interleukin-17A (IL-17A). Spectratyping and clonotype analyses were performed to assess different T cell subsets. RESULTS The numbers of CD4+CD161+ cells showing either the Th1 or the Th17/Th1 phenotype were higher in the SF than in the PB of children with JIA. The few Th17 cells from JIA SF underwent a spontaneous shift to the Th1 phenotype in vitro, whereas Th17 cells from the PB of healthy children shifted only in the presence of JIA SF; this effect was neutralized by antibody blockade of IL-12 activity. Spectratyping and clonotype analyses showed a similar skewing of the T cell receptor V(β) repertoire in both CD161+ Th17 cells and CD161+ Th1 cells derived from the SF of the same JIA patient. The frequencies of CD4+CD161+ cells, particularly the Th17/Th1 cells, in the JIA SF positively correlated with the erythrocyte sedimentation rate and levels of C-reactive protein. CONCLUSION These findings suggest that a shifting of CD4+CD161+ T cells from Th17 to the Th17/Th1 or Th1 phenotype can occur in the SF of children with oligoarticular-onset JIA, and indicate that the accumulation of these cells is correlated with parameters of inflammation. Thus, the results support the hypothesis that these cells may play a role in JIA disease activity.

Early Systemic Sclerosis: Serum Profiling of Factors Involved in Endothelial, T-cell, and Fibroblast Interplay is Marked by Elevated Interleukin-33 Levels

PurposeTo assess the serum profile of factors involved in endothelial, T-cell, and fibroblast interplay in patients with Raynaud’s phenomenon (RP) associated with nailfold vodeocapillaroscopy (NVC) scleroderma findings and/or systemic sclerosis (SSc) marker autoantibodies, recently labeled as early SSc patients.MethodsSerum levels of soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), CCL2, CXCL8, IL-13, IL-33, and transforming growth factor-β (TGF-β) were measured in 24 early SSc patients, 48 definite SSc patients, and 24 osteoarthritis/fibromyalgia controls by multiplex suspension immunoassay. All SSc patients were investigated for the presence/absence of preclinical and clinical organ involvement, SSc marker autoantibodies, and NVC abnormalities.ResultsSerum sICAM-1, CCL2, CXCL8, and IL-13 were increased in all SSc patients as compared to controls, and paralleled the severity of the disease subset (early SSc < limited cutaneous SSc < diffuse cutaneous SSc; p < 0.0001). Surprisingly, IL-33 was significantly higher in early SSc patients as compared to both controls (p < 0.01) and definite SSc patients (p < 0.05). In early SSc there were no differences in the investigated markers according to the functional and serological features assessed.ConclusionsOur study suggests that an endothelial, T-cell and fibroblast activation can be present in patients with early SSc and it is associated with a distinct profile of circulating factors involved in the cross-talk of these cells. The marked increase of IL-33 in early SSc patients suggests new routes of investigation of cell-cell dynamics in target tissues predating overt disease manifestations, thus opening to new therapeutic approaches.

Perianal Crohn’s disease and hidradenitis suppurativa: a possible common immunological scenario

BackgroundCrohn’s disease (CD) and Hidradenitis suppurativa (HS) are both chronic inflammatory diseases. The pathogenesis of these diseases is multifactorial, due to the interaction of genetic and environmental factors leading to a deregulated local immune response where T lymphocytes play a major role. To the best of our knowledge, no previous study has clarified whether the pathogenetic mechanism of perianal CD and HS is the same. We therefore analyzed the cellular expression pattern and the cytokine repertoire in three patients suffering from both perianal CD and HS.MethodsWe evaluated three patients affected by concurrent HS and CD with fistulizing perianal disease. Surgical specimens have been fixed and embedded in paraffin prior to sectioning for histological examination. Inflammatory tissue curettages have been recovered during intervention from perianal fistulas and HS lesions in order to analyze the phenotypic and functional characteristics of infiltrating T cells. In particular we evaluated T cells, by flow cytometry, for cytokine production profile and expression of surface markers. Moreover, analysis of the T cell repertoire was performed by means of spectratyping, in only one patient.ResultsA higher frequency of CD4+ CD161+ T lymphocytes has been detected in CD fistulas and in HS lesions than in peripheral blood (PB) samples. In the patient in whom we derived enough cells from the three sources, we found higher frequency of CD4+ IL-17- producing cells in HS lesion and fistula lesion compared to PB. It is noteworthy that the same clonotypes were expanded in this patient in T cells derived from both HS lesion and fistula lesion.ConclusionThe presence of numerous CD4+ CD161+ lymphocytes in fistula and HS lesion curettages suggests that these cells may play a pathogenic role, and candidates CD161 as a possible biological target for medical treatment.

Expression of functional tissue factor in activated T-lymphocytes in vitro and in vivo: A possible contribution of immunity to thrombosis?

OBJECTIVE T-lymphocyte activation plays an important role in the pathophysiology of acute coronary syndromes (ACS). Plaques from ACS patients show a selective oligoclonal expansion of T-cells, indicating a specific, antigen-driven recruitment of T-lymphocytes within the unstable lesions. At present, however, it is not known whether T-cells may contribute directly to thrombosis by expressing functional tissue factor (TF). Accordingly, the aim of the present study was to investigate whether T-cells are able to express functional TF in their activated status. METHODS In vitro, CD3(+)-cells, isolated from buffy coats, were stimulated with anti-CD3/CD28 beads, IL-6, TNF-α, IL-17, INF-γ or PMA/ionomycin. Following stimulation, TF expression on cell-surface, at gene and protein levels, as well as its procoagulant activity in whole cells and microparticles was measured. In vivo, TF expression was evaluated in CD3(+)-cells isolated from the aorta and the coronary sinus of ACS-NSTEMI and stable coronary artery disease (SCAD) patients. The presence of CD3(+)-TF(+)cells was also evaluated by immunohistochemistry in thrombi aspirated from ACS-STEMI patients. RESULTS PMA/ionomycin and IL-17 plus INF-γ stimulation resulted in a significant TF increase at gene and protein levels as well as at cell-surface expression. This was accompanied by a parallel increase in FXa generation, both in whole cells and in microparticles, indicating that the induced membrane-bound TF was active. Furthermore, transcardiac TF gradient was significantly higher in CD3(+)-cells obtained from ACS-patients compared to SCAD-patients. Interestingly, thrombi from ACS-STEMI patients resulted enriched in CD3(+)-cells, most of them expressing TF. CONCLUSIONS Our data demonstrate that activated T-lymphocytes in vitro express functional TF on their membranes, suggesting a direct pathophysiological role of these cells in the thrombotic process; this hypothesis is further supported by the observations in vivo that CD3(+)-cells from coronary circulation of ACS-NSTEMI patients show increased TF levels and that coronary thrombi from ACS-STEMI patients are enriched in CD3(+)-cells expressing TF.

A new marine-derived sulfoglycolipid triggers dendritic cell activation and immune adjuvant response

Dendritic Cells (DCs) recognize infectious non-self molecules and engage the adaptive immune system thereby initiating long lasting, antigen-specific responses. As such, the ability to activate DCs is considered a key tool to enhance the efficacy and quality of vaccination. Here we report a novel immunomodulatory sulfolipid named β-SQDG18 that prototypes a class of natural-derived glycolipids able to prime human DCs by a TLR2/TLR4-independent mechanism and trigger an efficient immune response in vivo. β-SQDG18 induces maturation of DC with the upregulation of MHC II molecules and co-stimulatory proteins (CD83, CD86), as well as pro-inflammatory cytokines (IL-12 and INF-γ). Mice immunized with OVA associated to β-SQDG18 (1:500) produced a titer of anti-OVA Ig comparable to traditional adjuvants. In an experimental model of melanoma, vaccination of C57BL/6 mice with β-SQDG18-adjuvanted hgp10 peptide elicited a protective response with a reduction in tumour growth and increase in survival.

Chitinase 3-like-1 is produced by human Th17 cells and correlates with the level of inflammation in juvenile idiopathic arthritis patients

BackgroundCHI3L1 is a chitinase-like protein without enzymatic activity, produced by activated macrophages, chondrocytes, neutrophils. Recent studies on arthritis, asthma, and inflammatory bowel diseases suggest that chitinases are important in inflammatory processes and tissue remodeling, but their production by human T cells, has never been reported.MethodsA microarray analysis of gene expression profile was performed on Th17 and classic Th1 cell clones and CHI3L1 was found among the up-regulated genes on Th17 cells. Different types of helper T cell clones (TCCs) were then evaluated by Real Time PCR (RT-PCR) for CHI3L1 mRNA expression; protein expression was investigated in cell lysates by western blotting and in cultures supernatants by ELISA. ELISA was also used to measure CHI3L1 in the serum and in the synovial fluid (SF) of juvenile idiopathic arthritis (JIA) patients.ResultsAt mRNA level CHI3L1 was highly expressed by Th17, Th17/Th1, non classic Th1 and even in Th17/Th2 cell clones, whereas it was virtually absent in CD161− classic Th1 and Th2 TCCs. CHI3L1 was also detected in cell culture supernatants of Th17 and Th17-derived cells but not of classic Th1. Moreover CHI3L1 was higher in the SF than in serum of JIA patients, and it positively correlated with the frequency of Th17 and non-classic Th1 cells in SF. CHI3L1 in SF also positively correlated with the C reactive protein (CRP) serum levels, and with the levels of some proinflammatory cytokines, such as IL-6 and p40, which is the common subunit of IL12 and IL23.ConclusionsHere we describe for the first time CHI3L1 production by T cells owing the Th17 family. Moreover the positive correlation found between the frequency of Th17 and Th17-derived cell subsets and CHI3L1 levels in SF of JIA patients, in agreement with the suggested role of these cells in inflammatory process, candidates CHI3L1 as a possible biological target in JIA treatment.

Nobiletin inhibits oxidized-LDL mediated expression of Tissue Factor in human endothelial cells through inhibition of NF-κB

INTRODUCTION Flavonoids are nutrients usually included in human diet with several significant biological activities. Nobiletin is a flavonoid that, besides having anti‐inflammatory and anti‐tumoral activity, seems to exert protective effects on cardiovascular system. Several studies investigated nobiletin as a natural drug to antagonize the atherosclerotic disease. On the contrary, literature about its potential role in modulating the main acute complication of atherosclerosis, thrombosis, is still scanty. Several studies have indicated that Tissue Factor (TF) plays a pivotal role in the pathophysiology of cardiovascular thrombotic events by triggering the formation of intracoronary thrombi. Oxidized‐LDL have an important role in promoting athero‐thrombotic events. This study investigates whether nobiletin might exert protective cardiovascular effects by preventing the oxidized‐LDL mediated expression of TF in human endothelial cells in vitro. Moreover, we have studied whether the nobiletin effects might be modulated by the inhibition of the NF‐&kgr;B pathway. METHODS AND RESULTS In HUVEC, ox‐LDL induced TF‐mRNA transcription as demonstrated by real time PCR and expression of functionally active TF as demonstrated by Western‐blot, FACS analysis and pro‐coagulant activity assay. Nobiletin prevented these ox‐LDL‐mediated effects by exerting antioxidant effects, finally leading to inhibition of the transcription factor NF‐&kgr;B. CONCLUSIONS These data suggest that nobiletin might be a potential antithrombotic agent of dietary origin. This flavonoid, through its antioxidant proprieties, might potentially exert an antithrombotic activity by inhibiting TF expression/activity in a cell population never investigated before in this context and that is normally represented in vessel wall such as endothelial cells.

AIRE polymorphism, melanoma antigen-specific T cell immunity, and susceptibility to melanoma

AIRE is involved in susceptibility to melanoma perhaps regulating T cell immunity against melanoma antigens (MA). To address this issue, AIRE and MAGEB2 expressions were measured by real time PCR in medullary thymic epithelial cells (mTECs) from two strains of C57BL/6 mice bearing either T or C allelic variant of the rs1800522 AIRE SNP. Moreover, the extent of apoptosis induced by mTECs in MAGEB2-specific T cells and the susceptibility to in vivo melanoma B16F10 cell challenge were compared in the two mouse strains. The C allelic variant, protective in humans against melanoma, induced lower AIRE and MAGEB2 expression in C57BL/6 mouse mTECs than the T allele. Moreover, mTECs expressing the C allelic variant induced lower extent of apoptosis in MAGEB2-specific syngeneic T cells than mTECs bearing the T allelic variant (p < 0.05). Vaccination against MAGEB2 induced higher frequency of MAGEB2-specific CTL and exerted higher protective effect against melanoma development in mice bearing the CC AIRE genotype than in those bearing the TT one (p < 0.05). These findings show that allelic variants of one AIRE SNP may differentially shape the MA-specific T cell repertoire potentially influencing susceptibility to melanoma.

Sphingosine Kinases promote IL-17 expression in human T lymphocytes

Sphingosine 1-phosphate (S1P) has a role in many cellular processes. S1P is involved in cell growth and apoptosis, regulation of cell trafficking, production of cytokines and chemokines. The kinases SphK1 and SphK2 (SphKs) phosphorilate Sphingosine (Sph) to S1P and several phosphatases revert S1P to sphingosine, thus assuring a balanced pool that can be depleted by a Sphingosine lyase in hexadecenal compounds and aldehydes. There are evidences that SphK1 and 2 may per se control cellular processes. Here, we report that Sph kinases regulate IL-17 expression in human T cells. SphKs inhibition impairs the production of IL-17, while their overexpression up-regulates expression of the cytokine through acetylation of IL-17 promoter. SphKs were up-regulated also in PBMCs of patients affected by IL-17 related diseases. Thus, S1P/S1P kinases axis is a mechanism likely to promote IL-17 expression in human T cells, representing a possible therapeutic target in human inflammatory diseases.

Regorafenib in combination with silybin as a novel potential strategy for the treatment of metastatic colorectal cancer

Purpose Regorafenib, an oral multikinase inhibitor, has demonstrated survival benefit in metastatic colorectal cancer (mCRC) patients that have progressed after all standard therapies. However, novel strategies to improve tolerability and enhance anti-cancer efficacy are needed. Experimental design We have evaluated in vitro the effects of regorafenib in combination with silybin, a biologically active component extracted from the seeds of Silybum marianum, in a panel of human colon cancer cells. Furthermore, we have prospectively treated a cohort of 22 refractory mCRC patients with regorafenib plus silybin. Results Treatment with regorafenib determined a dose-dependent growth inhibition whereas treatment with silybin had no anti-proliferative effects among all cancer cells tested. The combined treatment with regorafenib and silybin induced synergistic anti-proliferative and apoptotic effects by blocking PI3K/AKT/mTOR intracellular pathway. Moreover, combined treatment with regorafenib and silybin increased the production of reactive oxygen species levels within cells. In an exploratory proof of concept clinical study in a cohort of 22 mCRC patients after failure of all standard therapies, the clinical activity of regorafenib in combination with silybin was assessed. A median progression-free survival of 10.0 months and a median overall survival of 17.6 months were observed in these patients. These results suggest that the combined treatment potentially increases the clinical efficacy of regorafenib. Moreover, due to its anti-oxidative properties, silybin could protect patients from drug-induced liver damages, allowing to continue an effective anti-cancer therapy. Conclusions The present study suggests that silybin in combination with regorafenib is a promising strategy for treatment of metastatic colorectal patients.