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Anti-PD-1 antibodies revolutionized the treatment of advanced melanoma patients. However, one out of three do not respond to this therapy, with an overall poor prognosis. Identification of predictive biomarkers in patients receiving immune-based therapies is necessary for minimizing risk of toxicity and optimizing patient benefit and is still an important unmet clinical need. Recently, many studies have evaluated peripheral blood markers as potential biomarkers, but none so far have been validated. We collected at baseline peripheral blood samples from 18 consecutive advanced melanoma patients treated with anti-PD-1 therapy. Main pro- and anti-inflammatory cytokines were studied in PBMCs from baseline blood samples both evaluating mRNA expression by qRT-PCR and identifying PBMCs subpopulations by FACS analysis. We found that IFN-γ mRNA expression levels were significantly higher in responder patients compared to non-responder ones. Moreover, to better validate its role, we evaluated the IFN-γ/IL-10 ratio. This value was higher in responder patients. FACS analysis confirmed that CD4 + IFN-γ + PBMCs percentage was higher in responders. Our data suggest an interesting correlation between IFN-γ/IL-10 ratio and response to anti-PD-1 therapy in advanced melanoma patients, suggesting a new biomarker that could be easily incorporated in clinical practice.

The immune response arises from a fine balance of cellular and molecular mechanisms that provide for surveillance, tolerance, and elimination of dangers as pathogens. Improving the quality of the immune response remains a major goal in immunotherapy and vaccine development. Sulfavant A (SULF A) is a sulfolipid that has shown promising adjuvant activity in a cancer vaccine model. Here we report that SULF A is the first synthetic small molecule binding to the Triggering Receptor Expressed on Myeloid cells-2 (TREM2). The receptor engagement initiates an unconventional maturation of Dendritic cells (DCs) leading to upregulation of the Major Histocompatibility Complex class II (MHC Class II) and costimulatory molecules (CD83, CD86, DC54) without release of T helper type 1 (Th1) or 2 (Th2) cytokines. According to a TREM2 mechanism, this response is mediated by SYK-NFAT axis and is compromised by blockade and gene silencing of the receptor. Activation by SULF A preserved the DC functions to excite the allogeneic T cell response, and induced interleukin-10 (IL-10) release after lipopolysaccharide (LPS) stimulation. These results well support the adjuvant effect of SULF A and offer novel insights into the role of TREM2 in the differentiation of an unprecedented DC phenotype (homeDCs) that contributes to the maintenance of immune homeostasis without compromising lymphocyte activation and immunogenic response. The biological function of SULF-A may be of interest in various physiological and pathological processes involving the immune system.

The immune response arises from a fine balance of mechanisms that provide for surveillance, tolerance, and elimination of dangers. Sulfavant A (SULF A) is a sulfolipid with a promising adjuvant activity. Here we studied the mechanism of action of SULF A and addressed the identification of its molecular target in human dendritic cells (hDCs).Adjuvant effect and immunological response to SULF A were assessed on DCs derived from human donors. In addition to testing various reporter cells, target identification and downstream signalling was supported by a reverse pharmacology approach based on antibody blocking and gene silencing, crosstalk with TLR pathways, use of human allogeneic mixed lymphocyte reaction.SULF A binds to the Triggering Receptor Expressed on Myeloid cells-2 (TREM2) and initiates an unconventional maturation of hDCs leading to enhanced migration activity and up-regulation of MHC and co-stimulatory molecules without release of conventional cytokines. This response involves the SYK-NFAT axis and is compromised by blockade or gene silencing of TREM2. Activation by SULF A preserved the DC functions to excite the allogeneic T cell response, and increased interleukin-10 release after lipopolysaccharide stimulation.SULF A is the first synthetic small molecule that binds to TREM2. The receptor engagement drives differentiation of an unprecedented DC phenotype (homeDCs) that contributes to immune homeostasis without compromising lymphocyte activation and immunogenic response. This mechanism fully supports the adjuvant and immunoregulatory activity of SULF A. We also propose that the biological properties of SULF A can be of interest in various physiopathological mechanisms and therapies involving TREM2.

The marine environment is potentially a prolific source of small molecules with significant biological activities. In recent years, the development of new chromatographic phases and the progress in cell and molecular techniques have facilitated the search for marine natural products (MNPs) as novel pharmacophores and enhanced the success rate in the selection of new potential drug candidates. However, most of this exploration has so far been driven by anticancer research and has been limited to a reduced number of taxonomic groups. In this article, we report a test study on the screening potential of an in-house library of natural small molecules composed of 285 samples derived from 57 marine organisms that were chosen from among the major eukaryotic phyla so far represented in studies on bioactive MNPs. Both the extracts and SPE fractions of these organisms were simultaneously submitted to three different bioassays—two phenotypic and one enzymatic—for cytotoxic, antidiabetic, and antibacterial activity. On the whole, the screening of the MNP library selected 11 potential hits, but the distribution of the biological results showed that SPE fractionation increased the positive score regardless of the taxonomic group. In many cases, activity could be detected only in the enriched fractions after the elimination of the bulky effect due to salts. On a statistical basis, sponges and molluscs were confirmed to be the most significant source of cytotoxic and antimicrobial products, but other phyla were found to be effective with the other therapeutic targets.

Several studies have shown that T-cells might be involved in pathophysiology of acute coronary syndromes (ACS). Tissue factor (TF) plays a key role in ACS. Many evidences have indicated that some statins reduce TF expression in several cell types. However, literature about rosuvastatin and TF and about statins effects on T-cells is still scanty. Colchicine is an anti-inflammatory drug recently proven to have beneficial effects in ACS via unknown mechanisms. This study investigates the effects of colchicine and rosuvastatin on TF expression in oxLDL-activated T-cells. T-cells, isolated from buffy coats of healthy volunteers, were stimulated with oxLDL (50µg/dL). T-cells were pre-incubated with colchicine (10µM) or rosuvastatin (5µM) for 1h and then stimulated with oxLDL (50μg/mL). TF gene (RT-PCR), protein (western blot), surface expression (FACS) and procoagulant activity (FXa generation assay) were measured. NF-κB/IκB axis was examined by western blot analysis and translocation assay. Colchicine and rosuvastatin significantly reduced TF gene, and protein expression and procoagulant activity in oxLDL stimulated T-cells. This effect was associated with a significant reduction in TF surface expression as well as its procoagulant activity. These phenomena appear modulated by drug effects on the transcription factor NF-kB. Rosuvastatin and colchicine prevent TF expression in oxLDL-stimulated T-cells by modulating the NF-κB/IκB axis. Thus, we speculate that this might be another mechanism by which these drugs exert benefic cardiovascular effects.

Immunotherapy takes advantage of the immune system to prevent, control, and eliminate neoplastic cells. The research in the field has already led to major breakthroughs to treat cancer. In this work, we describe a platform that integrates in vitro bioassays to test the immune response and direct antitumor effects for the preclinical discovery of anticancer candidates. The platform relies on the use of dendritic cells that are professional antigen-presenting cells (APC) able to activate T cells and trigger a primary adaptive immune response. The experimental procedure is based on two phenotypic assays for the selection of chemical leads by both a panel of nine tumor cell lines and growth factor-dependent immature mouse dendritic cells (D1). The positive hits are then validated by a secondary test on human monocyte-derived dendritic cells (MoDCs). The aim of this approach is the selection of potential immunotherapeutic small molecules from natural extracts or chemical libraries.

Aims T-lymphocytes plays an important role in the pathophysiology of acute coronary syndromes. T-cell activation in vitro by pro-inflammatory cytokines may lead to functional tissue factor (TF) expression, indicating a possible contribution of immunity to thrombosis. Oxidized low-density lipoproteins (oxLDLs) are found abundantly in atherosclerotic plaques. We aimed at evaluating the effects of oxLDLs on TF expression in T cells and the role of the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). Methods and results CD3+ cells were isolated from healthy volunteers. Gene, protein, and surface expression of TF, as well as of LOX-1, were assessed at different time-points after oxLDL stimulation. To determine whether oxLDL-induced TF was LOX-1 dependent, T cells were pre-incubated with an LOX-1 inhibiting peptide (L-RBP) or with an anti-LOX-1 blocking antibody. To exclude that TF expression was mediated by reactive oxygen species (ROS) generation, oxLDL-stimulated T cells were pre-incubated with superoxide dismutase + catalase or with 4-Hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), an intracellular free radical scavenger. Finally, to determine if the observed findings in vitro may have a biological relevance, the presence of CD3+/TF+/LOX-1+ cells was evaluated by immunofluorescence in human carotid atherosclerotic lesions. oxLDLs induced functionally active TF expression in T cells in a dose- and time-dependent manner, independently on ROS generation. No effect was observed in native LDL-treated T cells. LOX-1 expression was also induced by oxLDLs in a time- and dose-dependent manner. Pre-incubation with L-RBP or anti-LOX-1 antibody almost completely inhibited oxLDL-mediated TF expression. Interestingly, human carotid plaques showed significant infiltration of CD3+ cells (mainly CD8+ cells), some of which were positive for both TF and LOX-1. Conclusion oxLDLs induce functional TF expression in T-lymphocytes in vitro via interaction of oxLDLs with LOX-1. Human carotid atherosclerotic plaques contain CD3+/CD8+cells that express both TF and LOX-1, indicating that also in patients these mechanisms may play an important role.

Background Little is known about the pathogenesis of scleromyxedema, a life-threatening fibromucinosis disease with immunological dysregulation. Objectives To investigate on T-cell phenotype, function and cytokine biology in search of new insights supporting the immunopathogenesis of the disease. Methods We analysed the frequency of circulating lymphocyte subsets, the T-cell maturation stage, the generation of antigen-specific T-cell lines and T-cell cytokine secretion. Results The analysis of T-cell maturation stage and the TCR spectratyping findings revealed that scleromyxedema patients showed clear immunological signs of long-lasting immune system activation and stimulation leading to a skewed T-cell repertoire. Moreover, these analyses showed that both CD4+ and CD8+ T cells from scleromyxedema patients have a profound deficiency (even after stimulation) relatively to the production of IFN-γ and IL17 with respect to healthy donor control cells, while they are massively skewed towards IL4 secretion after stimulation. Conclusions Our data indicate that a chronic Th2-skewed T-cell response against an unknown target antigen leading to abnormally high IL4 secretion, a pro-fibrotic cytokine, is a main immunological hallmark of scleromyxedema patients. These results, never reported before, may have a translational therapeutic value due to the availability of anti-IL4 agents such as dupilumab.

Tissue-resident memory (Trm) cells are specialized components of both CD4+ and CD8+ T cell subsets that persist in peripheral nonlymphoid tissues following infections and provide fast response in case of a secondary invasion by the same pathogen. Trm cells express the surface markers CD69, CD103, and the immune checkpoint molecule PD-1. Trm cells develop not only in the context of infections but also in tumors, where they can provide a line of defense as suggested by the positive correlation between the frequency of tumor-infiltrating Trm cells and patients' survival. Trm cells persistence in peripheral tissues depends on their adaptation to the local microenvironment and the presence of survival factors, mainly IL-7, IL-15, and Notch ligands. However, the cell sources of these factors are largely unknown, especially in the context of tumors. Here, we show that head-neck squamous cell carcinoma (HNSCC) is enriched in CD4+ and CD8+ T cells with a Trm phenotype. Moreover, we show that mesenchymal stromal cells that accumulate in HNSCC are a source of survival factors and allow proper expression of Trm-typical markers in a VCAM1-dependent manner.

We recently demonstrated that human T helper (Th) 17 cells, unlike Th1 cells, do not proliferate in response to T-cell receptor stimulation, mainly because of their reduced capacity to produce and respond to IL-2. In this study we show that their lower responsiveness to IL-2 is due to the selective expression of Musculin (MSC), a member of the basic helix-loop-helix transcription factors. We show that MSC expression in human Th17 cells is retinoic acid orphan receptor (ROR)γt-dependent, and allows the up-regulation of PPP2R2B, a regulatory member of the protein phosphatase 2A (PP2A) enzyme. High PPP2R2B levels in human Th17 cells were responsible for the reduced STAT5B Ser-193 phosphorylation upon IL-2 signalling and, therefore, impaired STAT5B DNA binding and transcriptional activity on IL-2 target genes. PP2A, observed in Th17 cells, controls also STAT3, dephosphorylating Ser727, thus increasing its activity which plays a crucial role in Th17 development and/or maintenance. Thus, our findings identify an additional mechanism responsible for the limited expansion of human Th17 cells, and could provide a further explanation for the rarity of these cells in inflamed tissues. This article is protected by copyright. All rights reserved

Background Pioglitazone, a synthetic peroxisome proliferator activated receptor (PPAR-γ) ligand, is known as an antidiabetic drug included in the thiazolidinediones (TZDs) class. It regulates the lipid and glucose cell metabolism and recently a role in the inhibition of numerous cancer cell processes has been described. Methods In our work we investigate the anti-tumor effects of pioglitazone in in vitro models of non small cell lung cancer (NSCLC) and also, we generated ex-vivo three-dimensional (3D) cultures from human lung adenocarcinoma (ADK) as a model to test drug efficacy observed in vitro. The inhibitory effect of pioglitazone on cell proliferation, apoptosis and cell invasion in a panel of human NSCLC cell lines was evaluated by multiple assays. Results Pioglitazone reduced proliferative and invasive abilities with an IC50 ranging between 5 and 10 μM and induced apoptosis of NSCLC cells. mRNA microarray expression profiling showed a down regulation of MAPK, Myc and Ras genes after treatment with pioglitazone; altered gene expression was confirmed by protein analysis in a dose-related reduction of survivin and phosphorylated proteins levels of MAPK pathway. Interestingly mRNA microarray analysis showed also that pioglitazone affects TGFβ pathway, which is important in the epithelial-to-mesenchimal transition (EMT) process, by down-regulating TGFβR1 and SMAD3 mRNA expression. In addition, extracellular acidification rate (ECAR) and a proportional reduction of markers of altered glucose metabolism in treated cells demonstrated also cell bioenergetics modulation by pioglitazone. Conclusions Data indicate that PPAR-γ agonists represent an attractive treatment tool and by suppression of cell growth (in vitro and ex vivo models) and of invasion via blockade of MAPK cascade and TGFβ/SMADs signaling, respectively, and its role in cancer bioenergetics and metabolism indicate that PPAR-γ agonists represent an attractive treatment tool for NSCLC.

Manipulation of the immune response is a game changer in lung cancer treatment, revolutionizing management. PD1 and CTLA4 are dynamically expressed on different T cell subsets that can either disrupt or sustain tumor growth. Monoclonal antibodies (MoAbs) against PD1/PDL1 and CTLA4 have shown that inhibitory signals can be impaired, blocking T cell activation and function. MoAbs, used as both single-agents or in combination with standard therapy for the treatment of advanced non-small cell lung cancer (NSCLC), have exhibited advantages in terms of overall survival and response rate; nivolumab, pembrolizumab, atezolizumab and more recently, durvalumab, have already been approved for lung cancer treatment and more compounds are in the pipeline. A better understanding of signaling elicited by these antibodies on T cell subsets, as well as identification of biological determinants of sensitivity, resistance and correlates of efficacy, will help to define the mechanisms of antitumor responses. In addition, the relevance of T regulatory cells (Treg) involved in immune responses in cancer is attracting increasing interest. A major challenge for future research is to understand why a durable response to immune checkpoint inhibitors (ICIs) occurs only in subsets of patients and the mechanisms of resistance after an initial response. This review will explore current understanding and future direction of research on ICI treatment in lung cancer and the impact of tumor immune microenvironment n influencing clinical responses.

Background Anti-PD-1/PD-L1 drugs are effective as monotherapy in a proportion of NSCLC patients and there is a strong rationale for combining them with targeted therapy. Inhibition of MAPK pathway may have pleiotropic effects on the microenvironment. This work investigates the efficacy of combining MEK and PD-L1 inhibition in pre-clinical and ex-vivo NSCLC models. Methods We studied the effects of MEK inhibitors (MEK-I) on PD-L1 and MCH-I protein expression and cytokine production in vitro in NSCLC cell lines and in PBMCs from healthy donors and NSCLC patients, the efficacy of combining MEK-I with anti-PD-L1 antibody in ex-vivo human spheroid cultures obtained from fresh biopsies from NSCLC patients in terms of cell growth arrest, cytokine production and T-cell activation by flow cytometry. Results MEK-I modulates in–vitro the immune micro-environment through a transcriptionally decrease of PD-L1 expression, enhance of MHC-I expression on tumor cells, increase of the production of several cytokines, like IFNγ, IL-6, IL-1β and TNFα. These effects trigger a more permissive anti-tumor immune reaction, recruiting immune cells to the tumor sites. We confirmed these data on ex-vivo human spheroids, showing a synergism of MEK and PD-L1 inhibition as result of both direct cancer cell toxicity of MEK-I and its immune-stimulatory effect on cytokine secretion profile of cancer cells and PBMCs with the induction of the ones that sustain an immune-reactive and inflammatory micro-environment. Conclusions Our work shows the biological rationale for combining immunotherapy with MEK-I in a reproducible ex-vivo 3D-culture model, useful to predict sensitivity of patients to such therapies. Electronic supplementary material The online version of this article (10.1186/s13046-019-1257-1) contains supplementary material, which is available to authorized users.

Colorectal cancer; Epidermal growth factor receptor (EGFR); MAPK pathway Càncer colorectal; Receptor epidèrmic de factor del creixement (EGFR); Via MAPK Cáncer colorrectal; Receptor epidérmico de factor del crecimiento (EGFR); Vía MAPK BACKGROUND: Previous studies showed that the combination of an anti-Epidermal growth factor (EGFR) and a MEK-inhibitor is able to prevent the onset of resistance to anti-EGFR monoclonal antibodies in KRAS-wild type colorectal cancer (CRC), while the same combination reverts anti-EGFR primary resistance in KRAS mutated CRC cell lines. However, rapid onset of resistance is a limit to combination therapies in KRAS mutated CRC. METHODS: We generated four different KRAS mutated CRC cell lines resistant to a combination of cetuximab (an anti-EGFR antibody) and refametinib (a selective MEK-inhibitor) after continuous exposure to increasing concentration of the drugs. We characterized these resistant cell lines by evaluating the expression and activation status of a panel of receptor tyrosine kinases (RTKs) and intracellular transducers by immunoblot and qRT-PCR. Oncomine comprehensive assay and microarray analysis were carried out to investigate new acquired mutations or transcriptomic adaptation, respectively, in the resistant cell lines. Immunofluorescence assay was used to show the localization of RTKs in resistant and parental clones. RESULTS: We found that PI3K-AKT pathway activation acts as an escape mechanism in cell lines with acquired resistance to combined inhibition of EGFR and MEK. AKT pathway activation is coupled to the activation of multiple RTKs such as HER2, HER3 and IGF1R, though its pharmacological inhibition is not sufficient to revert the resistant phenotype. PI3K pathway activation is mediated by autocrine loops and by heterodimerization of multiple receptors. CONCLUSIONS: PI3K activation plays a central role in the acquired resistance to the combination of anti-EGFR and MEK-inhibitor in KRAS mutated colorectal cancer cell lines. PI3K activation is cooperatively achieved through the activation of multiple RTKs such as HER2, HER3 and IGF1R.

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.

// Giuseppina Conteduca 1 , Daniela Fenoglio 1,2,3 , Alessia Parodi 1 , Florinda Battaglia 1 , Francesca Kalli 1 , Simone Negrini 1 , Samuele Tardito 1 , Francesca Ferrera 1 , Annalisa Salis 1 , Enrico Millo 1 , Giuseppe Pasquale 4 , Giusi Barra 4 , Gianluca Damonte 1 , Francesco Indiveri 1,2 , Soldano Ferrone 5,* and Gilberto Filaci 1,2,3,* 1 Centre of Excellence for Biomedical Research, University of Genoa, Genoa, Italy 2 Department of Internal Medicine, University of Genoa, Genoa, Italy 3 IRCCS AOU San Martino – IST, Genoa, Italy 4 Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy 5 Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA * These authors have contributed equally to the manuscript Correspondence to: Gilberto Filaci, email: // Keywords : AIRE, MAGE, medullary thymic epithelial cells, single nucleotide polymorphism, tolerance, Immunology and Microbiology Section, Immune response, Immunity Received : January 27, 2016 Accepted : August 08, 2016 Published : August 22, 2016 Abstract 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.

Background Antibody-dependent cell-mediated cytotoxicity (ADCC) may mediate antitumour activity of IgG1-isotype monoclonal antibody (mAb), suggesting as potential treatment combination of IgG1-mAbs, anti-epidermal growth factor receptor cetuximab and anti-programmed death-ligand-1 avelumab. Methods We evaluated ADCC induction in lung cancer cells by lactate dehydrogenase (LDH) release assay. Antitumour activity and safety of cetuximab plus avelumab were explored in a single-arm proof-of-concept study in pre-treated non-small cell lung cancer (NSCLC) patients (pt) (Cetuximab-AVElumab-lung, CAVE-Lung). Search for predictive biomarkers of response was done. Results Avelumab plus cetuximab induced ADCC in NSCLC cells in vitro in presence of natural killers (NK) from healthy donors (HD) or NSCLC pt, as effectors. Sixteen relapsed NSCLC pt were treated with avelumab plus cetuximab. Antitumour activity was observed in 6/16 pt, defined by progression free survival (PFS) ≥8 months, with 4 of them still on treatment at data lock time (range, 14–19 months). Of note, 3/6 responders had received as previous line anti-programmed death-1 therapy. In responders, clinical benefit was accompanied by significant increase in LDH release over baseline at the first radiological evaluation (8 weeks) (p=0.01) and by early skin toxicity; while in the 10 non-responders, that had PFS ≤5 months, LDH release tends to reduce. Baseline circulating DNA levels were higher in non-responders compared with responders and HD (p=0.026) and decrease in responders during therapy. Mutations in DNA damage responsive family genes were found in responders. Conclusion Cetuximab and avelumab activates NSCLC pt NK cells. Ex vivo evaluation of ADCC, circulating DNA levels and early skin toxicity may predict response to cetuximab plus avelumab in NSCLC. EUDRACT 2017-004195-58

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.

Background AXL and transforming growth factor β (TGF-β) signalling pathways play a key role in modulating tumour microenvironment by promoting epithelial to mesenchymal transition (EMT), stromal activation and regulating immune response in colorectal cancer (CRC). Here we have evaluated the effect of double blockade of TGF-β and AXL receptors, as an innovative therapeutic strategy for CRC. Methods We assessed the correlation of TGF-β and AXL by an in silico analysis of a human CRC gene expression profile database. Afterwards, an evaluation of AXL expression of in a panel of human CRC cell lines by Western Blot (WB) and Real time PCR was performed. The sensitivity of HCT116 and LOVO cells to treatment with galunisertib (LY21209761), a TGF-β R1 inhibitor, and R428, an AXL inhibitor, was assessed by MTT, cell migration, and colony forming assays. Furthermore we generated patient derived 3D spheroid cultures from primary CRC, and tested their susceptibility to galunisertib and R428 by MTT assay. Finally, in vivo experiments were done with HCT116 and LOVO tumour xenografts in immunodeficient mice. Results In silico analysis showed an association between high expression levels of AXL and TGF-β R1 in CMS4 CRC. AXL was differently expressed on cell lines, and interestingly it resulted increased in HCT116 and LOVO after TGF-β inhibition, probably representing a mechanism of cancer cell escape. Dual blockade with galunisertib and R428 determined a reduction in cell migration of 50% in HCT116 and 37% in LOVO cells, respectively, and colony formation of approximately 90 % in both cell lines. Moreover, combined treatment displayed a strong synergistic activity in 3D cultures derived from five human CRC samples, resulting in the inhibition of proliferation ranging from 80 to 90%. The in vivo experiments of HCT116 and LOVO subcutaneous xenograft models are currently on going and results will be presented. Conclusions Combined TGF-β and AXL inhibition showed a promising activity in preclinical models of CRC and could represent a novel potential therapeutic strategy for patients with CRC. Legal entity responsible for the study Universita degli studi della Campania "Luigi Vanvitelli". Funding ICURE project, Universita degli studi della Campania "Luigi Vanvitelli". Disclosure D. Melisi: Research grant/Funding (self): Lilly.

Background Previous studies have demonstrated that IgG1 mAbs as cetuximab, stimulate Antibody-Dependent Cell Cytotoxicity (ADCC). Among immune checkpoint inhibitors, avelumab is the only fully human IgG1 anti-PD-L1 mAb with ADCC properties. Anti-PD-L1 and anti-EGFR mediated NK cytotoxicity is evaluated. Methods LDH release was analyzed to study NK-mediated cytotoxicity by LDH Cytotoxicity Assay Kit and results was correlated to the level of PD-L1, EGFR and MHC-I cell surface expression analyzed by flow cytometry. NK-mediated cytotoxicity of the combination of anti-PD-L1 and anti-EGFR mAbs was studied in a panel of NSCLC cells lines encompassing different tumor types, using as effector NK cells isolated from healthy donors or NSCLC patients. Results PD-L1/EGFR/MHC-I expression levels correlated with enhanced ADCC lysis by the combination of avelumab and cetuximab as demonstrated by LDH assay, CD16 and CD107a mRNA. No significant difference in avelumab plus cetuximab-mediated ADCC between NK cells from healthy donors or from NSCLC patients was observed with a trend in favor of cancer patients, indicating that NK from cancer patients maintain lytic activity. ADCC capability of NK cells isolated from patients enrolled in the phase II study CAVE (Cetuximab-AVElumab)-lung, a single arm phase II clinical study of the combination of avelumab plus cetuximab in the second line treatment of metastatic non small cell lung cancer (NSCLC) patients (EUDRACT 2017- 004195-58) study resulted significantly enhanced after the experimental treatment compared to untreated baseline and healthy donors samples. Conclusions The combination of anti-EGFR and anti PD-L1 IgG1 antibodies is synergistic in terms of ADCC, where each antibody complements each other by promoting a more permissive immune reaction against the tumor, active also in otherwise immune-resistant cancers. Legal entity responsible for the study Universita degli studi della Campania Luigi Vanvitelli. Funding Merck KGaA. Disclosure F. Ciardiello: Advisory / Consultancy, Research grant / Funding (institution): Roche; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Sanofi; Advisory / Consultancy: Servier; Advisory / Consultancy: BMS; Advisory / Consultancy: Cellgene; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Ipsen. F. Morgillo: Advisory / Consultancy: MSD; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca. All other authors have declared no conflicts of interest.

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.

Background IL-17A has been implicated in the pathogenesis of systemic sclerosis (SSc) (1). We previously showed that skewed peripheral blood mononuclear cells (PBMCs) from SSc patients can induce Fas-mediated apoptosis in co-cultured autologous skin fibrobalsts (2). Objectives We therefore aimed to investigate IL-17A expression and effects in these co-cultures. Methods PBMCs and skin fibroblasts from 5 dcSSc patients with disease duration Results IL17A mRNA in co-cultured PBMCs was increased by 11.5 fold (p Conclusions Our results support the role of IL-17A in the pathogenesis of SSc. Furthermore, here we first show that IL-17A up-regulation in co-cultured PBMCs might play antifibrotic effects in autologous skin fibroblasts and might be implicated in fibroblast apoptosis, interphering with the FAS/FASL pathway. References Brembilla NC, Chizzolini C. T cell abnormalities in systemic sclerosis with a focus on Th17 cells. Eur Cytokine Netw 2012; 23: 128–39. De Palma R et al. Peripheral T cells from patients with early systemic sclerosis kill autologous fibroblasts in co-culture: is T-cell response aimed to play a protective role? Rheumatology (Oxford) 2010; 49: 1257–66. Disclosure of Interest None declared

Thrombosis is the main pathophysiological mechanism in Acute Coronary Syndromes (ACS), and involves the activation of platelets and of Tissue Factor (TF)-dependent extrinsic coagulation pathway. TF-mRNA and antigen are detectable in the adventitia of normal vessels. On the contrary, little TF immunoreactivity is measurable in the smooth muscle cells of uninjured vessels and unperturbed endothelial cells, being in contact with circulating blood, usually do not express TF activity. However, several stimuli are able to induce TF in endothelial cells, including thrombin. Thus in an acute "scenario", thrombin might be responsible for creating a prothombotic milieau. Bivalirudin (BIVA) is a synthetic, reversible direct thrombin inhibitor actually considered a valuable alternative to heparins in patients who need anticoagulation in the setting of ACS and percutaneous coronary intervention to avoid acute thrombotic events. In the present study we have investigated whether BIVA, by inhibiting thrombin, might have effects on TF expression and procoagulant activity in endothelial cells. Human Umbilical Endothelial Cells (HUVEC) were stimulated with thrombin or with the activated coagulation factors FVIIa/FXa for 2 hrs to evaluate TF-mRNA transcription by real-time PCR and for 6 hrs to measure TF expression/activity on cell surface by FACs analysis and procoagulant activity. In additional experiments HUVEC were pre-treated with BIVA for 1 hr before being stimulated and processed as above. Thrombin induced TF-mRNA transcription as well TF expression/activity on HUVEC shifting them to a procoagulant phenotype. On the contrary, the activated coagulation factors FVIIa/FXa did not affect TF expression/activity, indicating that thrombin plays a pivotal role in mediating this phenomenon. BIVA was able to prevent these thrombin deleterious effects. Data of the present study, although in vitro, suggest that BIVA, in the context of ACS, might significantly reduce thrombogenicity not only by acting as direct thrombin inhibitor but through its effects on TF expression/activity too.

// Floriana Morgillo 1 , Carminia Maria Della Corte 1 , Anna Diana 1 , Concetta di Mauro 2 , Vincenza Ciaramella 1 , Giusi Barra 3 , Valentina Belli 1 , Elisena Franzese 1 , Roberto Bianco 2 , Evaristo Maiello 4 , Ferdinando De Vita 1 , Fortunato Ciardiello 1 and Michele Orditura 1 1 Oncologia Medica, Dipartimento di Internistica Clinica e Sperimentale “F. Magrassi”, Universita degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy 2 Oncologia Medica, Dipartimento di Medicina Clinica e Chirurgia, Universita degli Studi di Napoli “Federico II”, Napoli, Italy 3 Immunologia Clinica, Dipartimento di Internistica Clinica e Sperimentale “F. Magrassi”, Universita degli Studi della Campania “Luigi Vanvitelli”, Napoli, Italy 4 IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy Correspondence to: Floriana Morgillo, email: florianamorgillo@yahoo.com , floriana.morgillo@unicampana.it Keywords: AKT, breast cancer, taselisib, ipatasertib, novel drugs Received: March 22, 2017 Accepted: July 26, 2017 Published: August 22, 2017 ABSTRACT Purpose: The Phosphatidylinositol 3-kinase (PI3Ks) pathway is commonly altereted in breast cancer patients, but its role is still unclear. Taselisib, a mutant PI3Kα selective inhibitor, and ipatasertib, an AKT inhibitor, are currently under investigation in clinical trials in combination with paclitaxel or hormonal therapies in breast cancer. The aim of this study was to evaluate if PI3K or AKT inhibition can prevent resistance to chemotherapy and potentiate its efficacy. Experimental design: The efficacy of combined treatment of ipatasertib and taselisib plus vinorelbine or paclitaxel or eribulin was evaluated in vitro on human breast cancer cells (with different expression profile of hormonal receptors, HER2, and of PI3Ka mutation) on cell survival by using MTT (3,(4,5-dimethylthiazol-2)2,5 difeniltetrazolium bromide) and colony forming assays on cell apoptosis by flow-cytometry analysis. We also investigated the effect of combined treatment on downstream intracellular signaling, by western blot analysis, and on metastatic properties, by migration assays. Finally, we analyzed changes in cell cytoskeleton by immunofluorescence. Results: A significant synergism of ipatasertib or taselisib plus anti-microtubule chemotherapy in terms of anti-proliferative, pro-apoptotic and anti-metastatic effect was observed. The combined treatment completely inhibited the activation of proteins downstream of PI3K and MAPK pathways and affected the expression of survivin. Combined treatments completely disorganized the cytoskeleton in human breast cancer cells, with contemporary delocalization of survivin from cytoplasm to nucleus, thus suggesting a potential mechanism for this combination. Conclusions: Targeting PI3K may enhance the efficacy of anti-microtubule drugs in human breast cancer cells.

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-kB pathway. 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-kappa 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-kappa 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. (C) 2016 Elsevier Inc. All rights reserved.

Background Molecular mechanisms driving acquired resistance to anti-EGFR therapies in metastatic Colorectal Cancer (mCRC) are complex but generally involve the activation of the downstream RAS-RAF-MEK-MAPK pathway. Methods In order to understand the mechanism underlying MEK inhibitor (MEKi) resistance, we generated three different MEKi resistant models, two all RAS WT (SW48-MR and LIM1215-MR) and one mutated in RAS (HCT116-MR). Results These models showed features related to the gene signature of Colorectal Cancer CMS4 with upregulation of immune pathway as confirmed by Microarray and Western blot analysis. In particular, moving forward the MEKi phenotype we assisted to the loss of epithelial features and acquisition of mesenchymal markers and morphology. Moreover, this change in the morphology is accompanied by up-regulation of PD-L1 expression and activation of EGFR and its downstream pathway, independently of cell line status mutation. To extend these in vitro findings, we performed an in vivo study using MC38 and CT26 MEKi resistant syngeneic models that we have previously generated. Combined treatment of MEKi, EGFR inhibitor (EGFRi) and PD-L1inhibitor (PD-L1i) resulted in a marked inhibition of tumor growth in both MC38–MR and CT26-MR xenograft model. Conclusions These results suggest a strategy to potentially overcome immunotherapy resistance in CMS4-like tumors and to improve the efficacy of MEK inhibition by co-treatment with other agents providing an additional therapeutic strategy via modulation of host immune responses. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Background In the era of precision medicine, cancer treatment strategies are aimed to be patient-tailored. Here, we report a translational study conducted on a NSCLC patient where the potentiality of ex vivo spheroidal cultures and peripheral blood biomarkers were investigated to analyze correspondence with treatment response. Methods We developed a protocol to generate ex vivo spheroidal cultures from patient’s surgical sample that has been used to assess drug sensitivity through cell proliferation MTT assay. Primary tumor tissue, patient-derived spheroids and patient’s circulating tumor DNA (ctDNA) were characterized through immunohistochemistry (IHC), immunofluorescence and next generation sequencing (NSG) analysis. Tumor infiltrating lymphocytes (TILs) from surgical specimen were analyzed by FACS and the analysis of TCR repertoire was conducted using Spectratyping technique. Moreover, peripheral blood samples collected at different time points underwent qPCR analysis to assess cytokines expression and flow cytometry to study peripheral blood mononuclear cells (PBMCs). All these data were correlated with clinical and radiological evaluations. Results Immunohistochemistry, immunofluorescence, NGS analysis and TCR repertoire assay showed elevated concordance among primary tumor tissue, spheroids and ctDNA. Cisplatin-based chemotherapy and anti-PD-1 treatment sensitivity assessed in spheroidal cultures allowed us to anticipate patient response to chemo- and immunotherapy. Furthermore, circulating cytokines expression levels and lymphocytes subpopulations profiling correlated with clinical and radiological response to first line anti-PD-1 therapy. Conclusions This approach demonstrated the feasibility of using spheroidal cultures, cytokines expression levels and PBMCs profiling to follow patient’s disease history and response to treatment in parallel with clinical and radiological evaluation. Legal entity responsible for the study Universita degli Studi della Campania Luigi Vanvitelli. Funding Has not received any funding. Disclosure F. Ciardiello: Advisory / Consultancy, Research grant / Funding (institution): Roche; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy, Research grant / Funding (institution): Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Sanofi; Advisory / Consultancy: Servier; Advisory / Consultancy: BMS; Advisory / Consultancy: Cellgene; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Ipsen. F. Morgillo: Advisory / Consultancy: MSD; Advisory / Consultancy: Lilly; Research grant / Funding (institution): AstraZeneca. All other authors have declared no conflicts of interest.

Background Anti-PD-1 antibodies represent nowadays a first-choice therapy for metastatic melanoma patients. Despite impressive results in terms of PFS and OS, a proportion of patients does not respond to anti-PD-1 therapy with an overall poor prognosis. Identification of predictive biomarkers is considered an important unmet clinical need to avoid expensive and potentially harmful drugs in patients who will not respond to them. In the last years, many studies have evaluated the role of cytokines on both blood and tissue samples as predictive biomarkers for immunotherapy, with encouraging results. Methods Blood samples from 18 patients with metastatic melanoma treated with anti-PD-1 antibodies as first line therapy were collected at baseline. 8 patients were classified as non-responders (best response: PD excluding pseudo-progression with median PFS of 2 months) and 10 patients as responders (best response: PR or CR, with median PFS of 17 months). mRNA expression levels of the main pro- and anti-inflammatory cytokines were evaluated by Real time quantitative PCR in PBMCs obtained from baseline blood samples. Unpaired two-tailed t-test was used for statistical analysis. Results IFN-γ mRNA expression levels were higher in responder patients (p 0.05). Combining data for each patient, we noticed a correlation between higher levels of IFN-γ and lower levels of IL-10 for responders and vice versa. Starting from these findings, we observed that the IFN-γ/IL-10 ratio was higher (median: 43,3 vs 5,2) in responders (p Conclusions Our data suggest an interesting correlation between IFN-γ/IL-10 ratio and response to anti-PD-1 therapy in melanoma patients. This correlation seems to be stronger than using IFN-γ expression levels alone probably because of the influence of anti-inflammatory cytokines. Since this is an exploratory and retrospective analysis of 18 patients, a larger population should be tested to validate our results. Legal entity responsible for the study Dipartimento di Medicina di Precisione, Universita degli studi della Campania Luigi Vanvitelli. Funding Has not received any funding. Disclosure F. Ciardiello: Advisory / Consultancy: Roche; Advisory / Consultancy: Amgen; Advisory / Consultancy: Merck; Advisory / Consultancy: Sanofi; Advisory / Consultancy: Bayer; Advisory / Consultancy: Pfizer; Advisory / Consultancy: Servier; Advisory / Consultancy: BMS; Advisory / Consultancy: Cellgene; Advisory / Consultancy: Lilly; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): Roche; Research grant / Funding (institution): Merck; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Takeda. T. Troiani: Research grant / Funding (institution): Roche; Research grant / Funding (institution): Sanofi; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Servier; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Bayer. All other authors have declared no conflicts of interest.

According to the consensus molecular subtypes (CMS), almost 23% of human colorectal cancer (CRC) are classified in the CMS4 group, characterized by a mesenchymal signature and the activation of transforming growth factor β (TGF-β) signaling. AXL is a tyrosine kinase receptor involved in epithelial to mesenchymal transition, angiogenesis and immune modulation in CRC. We have previously demonstrated that AXL gene is amplified in approximately 5% of human CRC, and that AXL inhibition causes a significant blockade of CRC cell proliferation and migration. Here we have evaluated the role of TGF-β signaling and the potential interaction between TGF-β and AXL in human CRC cell lines. We assessed the expression and activation of TGF-β and AXL in a panel of six human CRC cell lines by western blot (WB) and real time PCR. We tested the sensitivity of HCT116 and LOVO cells to treatment with galunisertib ( LY21209761), a selective TGF-β R1 inhibitor, by MTT, cell invasion, wound healing and soft-agar colony forming assays. Further, intracellular CRC cell signaling was evaluated following galunisertib treatment by WB. TGF-β receptors 1 and 2 were expressed in all human CRC cell lines (HCT116, SW480, LOVO, LIM 1215, SW48 and CaCo2), whereas AXL expression was restricted to HCT116, SW480, LOVO cells. Treatment with galunisertib had little or no effect on cancer cell growth, whereas it partially reduced TGF-β induced cell migration, invasion and colony formation in HCT116 and LOVO cells (that co-expressed both TGF-β receptors and AXL). Interestingly, TGF-β inhibition resulted in a concomitant significant activation of AXL and p38 MAPK in both cell lines, that could represent a cancer cell adaptive mechanism of resistance to galunisertib treatment. These results suggest a potential functional cross talk between TGF-β, AXL and p38 MAPK signals in human CRC cells. In this respect, further experiments are ongoing to better understand this interaction with the aim of identifying potential novel anti-AXL and anti-TGF-β therapeutic strategies. Citation Format: Davide Ciardiello, Pietro Paolo Vitiello, Nunzia Matrone, Valentina Belli, Claudia Cardone, Luca Poliero, Carola Borrelli, Gianluca Arrichiello, Giulia Martini, Vincenza Ciaramella, Giusi Barra, Floriana Morgillo, Teresa Troiani, Davide Melisi, Fortunato Ciardiello, Erika Martinelli. Inhibition of TGFβ in colorectal cancer cells is associated with a compensatory activation of AXL and p38 MAPK signaling pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2627.

Background: CHI3L1 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. Methods: A 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. Results: At 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. Conclusions: Here 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.

Pregnancy-associated plasma protein-A (PAPP-A) is a metalloproteinase with a controversial role in pathophysiology of cardiovascular disease. It seems involved in progression of atherosclerosis and is widely represented in atherosclerotic plaque. PAPP-A plasma levels are elevated in patients with acute coronary syndromes (ACS), thus it has been suggested that it might be a prognostic marker for developing major cardiovascular events. However, the pathophysiological link(s) between PAPP-A and ACS are still unknown. Several studies have indicated that tissue factor (TF) plays a pivotal role in the pathophysiology of ACS by triggering the formation of intracoronary thrombi following endothelial injury. This study investigates whether PAPP-A, at concentrations measurable in ACS patients, might induce TF expression in human endothelial cells in culture (HUVEC). In HUVEC, PAPP-A induced TF-mRNA transcription as demonstrated by real time PCR and expression of functionally active TF as demonstrated by FACS analysis and pro-coagulant activity assay. PAPP-A induced TF expression through the activation of Akt/NF-κB axis, as demonstrated by luciferase assay and by suppression of TF-mRNA transcription as well as of TF expression/activity by Akt and NF-κB inhibitors. These data indicate that PAPP-A promotes TF expression in human endothelial cells and support the hypothesis that this proteinase, besides being involved in progression of atherosclerosis, does not represent an independent risk factor for adverse cardiovascular events, but it rather might play an "active" role in the pathophysiology of ACS as an effector molecule able to induce a pro-thrombotic phenotype in endothelial cells.