Natural killer cells modulate motor neuron-immune cell cross talk in models of Amyotrophic Lateral Sclerosis.

In amyotrophic lateral sclerosis (ALS), immune cells and glia contribute to motor neuron (MN) degeneration. We report the presence of NK cells in post-mortem ALS motor cortex and spinal cord tissues, and the expression of NKG2D ligands on MNs. Using a mouse model of familial-ALS, hSOD1G93A, we demonstrate NK cell accumulation in the motor cortex and spinal cord, with an early CCL2-dependent peak. NK cell depletion reduces the pace of MN degeneration, delays motor impairment and increases survival. This is confirmed in another ALS mouse model, TDP43A315T. NK cells are neurotoxic to hSOD1G93A MNs which express NKG2D ligands, while IFNγ produced by NK cells instructs microglia toward an inflammatory phenotype, and impairs FOXP3+/Treg cell infiltration in the spinal cord of hSOD1G93A mice. Together, these data suggest a role of NK cells in determining the onset and progression of MN degeneration in ALS, and in modulating Treg recruitment and microglia phenotype.

Gut microbiota alterations affect glioma growth and innate immune cells involved in tumor immunosurveillance in mice.

Glioma is a CNS tumor with few therapeutic options. Recently, host microbiota has been involved in the immune modulation of different tumors, but no data are available on the possible effects of the gut-immune axis on brain tumors. Here, we investigated the effect of gut microbiota alteration in a syngeneic (GL261) mouse model of glioma, treating mice with two antibiotics (ABX) and evaluating the effects on tumor growth, microbe composition, natural killer (NK) cells and microglia phenotype. We report that ABX treatment (i) altered the intestinal microbiota at family level, (ii) reduced cytotoxic NK cell subsets, and (iii) altered the expression of inflammatory and homeostatic proteins in microglia. All these findings could contribute to the increased growth of intracranial glioma that was observed after ABX treatment. These results demonstrate that chronic ABX administration alters microbiota composition and contributes to modulate brain immune state paving the way to glioma growth.

IFN-γ/IL-6 and related cytokines in chronic spontaneous urticaria: evaluation of their pathogenetic role and changes during omalizumab therapy.

BACKGROUND: Recent studies highlight that high levels of cytokines may precede the onset of many systemic autoimmune disorders and may also be related to chronic spontaneous urticaria (CSU) activity. METHODS: Eight patients with CSU candidate to omalizumab therapy were enrolled. Four healthy controls were included with the purpose of comparing baseline cytokine levels. We evaluated serum levels of IFN-γ, IL-2, 4, 6, 8, and 10, TNF-α, and GM-CSF. For the patient group, venous blood samples were drawn at T0, T1 (1 week after first drug administration), T2 (after 3 months), T3 (after 6 months), and in case of relapse. Cytokine levels were measured using the human cytokines 8-plex kit. Disease activity and effect of therapy were calculated by means of Urticaria Activity Score 7. RESULTS: Higher levels of IL-6 and IFN-γ were found in patients with CSU compared to those observed in the control group. Moreover, a common trend between these cytokines and the clinical history of disease could be hypothesized, with a decrease in levels of IFN-γ and IL-6 following remission of CSU with omalizumab treatment. Levels of other tested cytokines were similar between patients and healthy subjects. CONCLUSION: IFN-γ and IL-6 are proinflammatory cytokines that are strongly related to autoimmunity. Despite being limited by the small sample size, our data offer new insight into a better understanding of the pathogenesis of CSU and support the need for further investigations.

1H-NMR metabolomics reveals the Glabrescione B exacerbation of glycolytic metabolism beside the cell growth inhibitory effect in glioma.

BACKGROUND: Glioma is the most common and primary brain tumors in adults. Despite the available multimodal therapies, glioma patients appear to have a poor prognosis. The Hedgehog (Hh) signaling is involved in tumorigenesis and emerged as a promising target for brain tumors. Glabrescione B (GlaB) has been recently identified as the first direct inhibitor of Gli1, the downstream effector of the pathway. METHODS: We established the overexpression of Gli1 in murine glioma cells (GL261) and GlaB effect on cell viability. We used 1H-nuclear magnetic resonance (NMR) metabolomic approach to obtain informative metabolic snapshots of GL261 cells acquired at different time points during GlaB treatment. The activation of AMP activated protein Kinase (AMPK) induced by GlaB was established by western blot. After the orthotopic GL261 cells injection in the right striatum of C57BL6 mice and the intranasal (IN) GlaB/mPEG5kDa-Cholane treatment, the tumor growth was evaluated. The High Performance Liquid Chromatography (HPLC) combined with Mass Spectrometry (MS) was used to quantify GlaB in brain extracts of treated mice. RESULTS: We found that GlaB affected the growth of murine glioma cells both in vitro and in vivo animal model. Using an untargeted 1H-NMR metabolomic approach, we found that GlaB stimulated the glycolytic metabolism in glioma, increasing lactate production. The high glycolytic rate could in part support the cytotoxic effects of GlaB, since the simultaneous blockade of lactate efflux with α-cyano-4-hydroxycinnamic acid (ACCA) affected glioma cell growth. According to the metabolomic data, we found that GlaB increased the phosphorylation of AMPK, a cellular energy sensor involved in the anabolic-to-catabolic transition. CONCLUSIONS: Our results indicate that GlaB inhibits glioma cell growth and exacerbates Warburg effect, increasing lactate production. In addition, the simultaneous blockade of Gli1 and lactate efflux amplifies the anti-tumor effect in vivo, providing new potential therapeutic strategy for this brain tumor.

Ca2+-activated K+ channels modulate microglia affecting motor neuron survival in hSOD1G93A mice.

Recent studies described a critical role for microglia in amyotrophic lateral sclerosis (ALS), where these CNS-resident immune cells participate in the establishment of an inflammatory microenvironment that contributes to motor neuron degeneration. Understanding the mechanisms leading to microglia activation in ALS could help to identify specific molecular pathways which could be targeted to reduce or delay motor neuron degeneration and muscle paralysis in patients. The intermediate-conductance calcium-activated potassium channel KCa3.1 has been reported to modulate the "pro-inflammatory" phenotype of microglia in different pathological conditions. We here investigated the effects of blocking KCa3.1 activity in the hSOD1G93AALS mouse model, which recapitulates many features of the human disease. We report that treatment of hSOD1G93A mice with a selective KCa3.1 inhibitor, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34), attenuates the "pro-inflammatory" phenotype of microglia in the spinal cord, reduces motor neuron death, delays onset of muscle weakness, and increases survival. Specifically, inhibition of KCa3.1 channels slowed muscle denervation, decreased the expression of the fetal acetylcholine receptor γ subunit and reduced neuromuscular junction damage. Taken together, these results demonstrate a key role for KCa3.1 in driving a pro-inflammatory microglia phenotype in ALS.

Environmental stimuli shape microglial plasticity in glioma.

In glioma, microglia and infiltrating macrophages are exposed to factors that force them to produce cytokines and chemokines, which contribute to tumor growth and to maintaining a pro-tumorigenic, immunosuppressed microenvironment. We demonstrate that housing glioma-bearing mice in enriched environment (EE) reverts the immunosuppressive phenotype of infiltrating myeloid cells, by modulating inflammatory gene expression. Under these conditions, the branching and patrolling activity of myeloid cells is increased, and their phagocytic activity is promoted. Modulation of gene expression depends on interferon-(IFN)-γ produced by natural killer (NK) cells. This modulation disappears in mice depleted of NK cells or lacking IFN-γ, and was mimicked by exogenous interleukin-15 (IL-15). Further, we describe a key role for brain-derived neurotrophic factor (BDNF) that is produced in the brain of mice housed in EE, in mediating the expression of IL-15 in CD11b+ cells. These data define novel mechanisms linking environmental cues to the acquisition of a pro-inflammatory, anti-tumor microenvironment in mouse brain.

WISP1 Is a Marker of Systemic and Adipose Tissue Inflammation in Dysmetabolic Subjects With or Without Type 2 Diabetes.

CONTEXT: Wnt1-inducible signaling pathway protein 1 (WISP1) is a novel adipokine participating in adipose tissue (AT) dysfunction; so far, no data on WISP1 in diabetes are available. OBJECTIVES: To evaluate plasma WISP1 in subjects with type 2 diabetes (T2D) and its correlates linked to AT inflammation. DESIGN AND PARTICIPANTS: For this cross-sectional study, 97 consecutive dysmetabolic patients were recruited at the diabetes outpatient clinics of Sapienza University in Rome; 71 of them had T2D, with (n = 35) or without (n = 36) obesity, and 26 were obese patients without diabetes. Twenty-one normal-weight nondiabetic individuals were enrolled as a control group. Study participants underwent clinical workup and blood sampling for metabolic/inflammatory characterization; magnetic resonance imaging (MRI) data on subcutaneous AT and visceral AT (VAT) area, hepatic fat content, and VAT homogeneity were available for most diabetic patients. RESULTS: Plasma WISP1 significantly increased throughout classes of obesity and correlated with greater VAT area, interleukin-8 (IL-8), and lower adiponectin levels, without differing between diabetic and nondiabetic participants. Higher IL-8 was the main determinant of increased WISP1. MRI-assessed VAT inhomogeneity was associated with higher WISP1, IL-8 and C-reactive protein levels, independent of obesity; high WISP1 strongly predicted VAT inhomogeneity (P < 0.001). CONCLUSIONS: WISP1 levels are increased in obese persons and are directly related to adiposity, independent of glycemic status or insulin resistance; moreover, they are strongly associated with increased plasma IL-8 and signal abnormalities of VAT. The overall data add insights to the mechanisms underlying metabolic alterations and may open a scenario for innovative therapeutic approaches for diabetes prevention and care.

Peripheral blood T cell alterations in newly diagnosed diffuse large B cell lymphoma patients and their long-term dynamics upon rituximab-based chemoimmunotherapy.

The importance of T cell-dependent immune responses in achieving long-term cure of chemoimmunotherapy-treated cancer patients is underscored by the recently described "vaccinal effect" exerted by therapeutic mAbs. In accordance, pre- and post-therapy peripheral blood lymphopenia represents a well-established negative prognostic factor in DLBCL. We analyzed the phenotypic and functional (IFNγ production, and Granzyme B (GrzB) cytotoxic granule marker expression) profile of peripheral blood T lymphocyte subsets ("conventional" CD4+ and CD8+, FOXP3+CD25bright Treg, and "innate-like" CD56+) in DLBCL patients at diagnosis, and assessed the long-term impact of R-CHOP chemoimmunotherapy, in a prospective study. At diagnosis, DLBCL patients showed lower lymphocyte counts, due to selective decrement of CD4+ T (including Treg) and B lymphocytes. While all T cell subsets transiently decreased during therapy, CD4+ T cell and Treg remained significantly lower than controls, up to 1 year after R-CHOP. Phenotypically skewed profile of CD4+ and CD8+ T cell subsets associated with higher frequencies of IFNγ+ and GrzB+ cells at diagnosis, that transiently decreased during therapy, and re-attained persistently elevated levels, till up to 1 year after therapy. Differently, the pre-therapy elevated levels of circulating monocytes, and of plasma IL-6 and IL-10 rapidly normalized upon R-CHOP. In sum, we describe a quantitatively and functionally altered status of the peripheral blood T cell compartment in DLBCL patients at diagnosis, that persists long-term after tumor eradication, and it is only transiently perturbed by R-CHOP chemoimmunotherapy. Moreover, data suggest the association of selected T cell functional features with DLBCL phenotype, and with therapy outcome.

The Glycoside Oleandrin Reduces Glioma Growth with Direct and Indirect Effects on Tumor Cells.

Oleandrin is a glycoside that inhibits the ubiquitous enzyme Na+/K+-ATPase. In addition to its known effects on cardiac muscle, recent in vitro and in vivo evidence highlighted its potential for anticancer properties. Here, we evaluated for the first time the effect of oleandrin on brain tumors. To this aim, mice were transplanted with human or murine glioma and analyzed for tumor progression upon oleandrin treatment. In both systems, oleandrin impaired glioma development, reduced tumor size, and inhibited cell proliferation. We demonstrated that oleandrin does the following: (1) enhances the brain-derived neurotrophic factor (BDNF) level in the brain; (2) reduces both microglia/macrophage infiltration and CD68 immunoreactivity in the tumor mass; (3) decreases astrogliosis in peritumoral area; and (4) reduces glioma cell infiltration in healthy parenchyma. In BDNF-deficient mice (bdnftm1Jae/J) and in glioma cells silenced for TrkB receptor expression, oleandrin was not effective, indicating a crucial role for BDNF in oleandrin's protective and antitumor functions. In addition, we found that oleandrin increases survival of temozolomide-treated mice. These results encourage the development of oleandrin as possible coadjuvant agent in clinical trials of glioma treatment.SIGNIFICANCE STATEMENT In this work, we paved the road for a new therapeutic approach for the treatment of brain tumors, demonstrating the potential of using the cardioactive glycoside oleandrin as a coadjuvant drug to standard chemotherapeutics such as temozolomide. In murine models of glioma, we demonstrated that oleandrin significantly increased mouse survival and reduced tumor growth both directly on tumor cells and indirectly by promoting an antitumor brain microenvironment with a key protective role played by the neurotrophin brain-derived neurotrophic factor.

Local allergic rhinitis in children: Novel diagnostic features and potential biomarkers.

BACKGROUND: Local allergic rhinitis (LAR) is a phenotype of rhinitis that has been poorly studied in children. It is characterized by the same symptoms of allergic rhinitis but with the absence of markers of systemic atopy. OBJECTIVE: To identify children affected by LAR and to analyze the pathogenesis of this disease. We chose to focus our attention on interleukin (IL) and thymic stromal lymphopoietin (TSLP). METHODS: We enrolled 20 children affected by nonallergic rhinitis (negative skin-prick test results and serum specific immunoglobulin E [sIgE] values). Each patient underwent a nasal allergen provocation test (NAPT) with dust mite and grass pollen. Before and after NAPT, nasal lavage was performed to detect sIgE, IL-5, and TSLP; anterior active rhinomanometry was used to evaluate changes in nasal obstruction. RESULTS: Two patients were positive to a nonspecific NAPT and, thus, were excluded from the study. Of the remaining 18 children, 12 (66.7%) had positive results to at least one NAPT. Among these 12 patients, nasal sIgE levels for Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Lolium perenne increased significantly after NAPT (D. pteronyssinus, p < 0.005; D. farinae, p < 0.05; L. perenne, p < 0.05). Nasal IL-5 levels showed a significant increase after NAPT (p ≤ 0.006), and this increase was significantly higher in children who had positive NAPT results than in those patients with negative NAPT results (p ≤ 0.03). Among the 12 children who had a positive NAPT result, nasal TSLP was detected in 4 patients (33.3%) and its levels showed a relevant increase after NAPT, even though the difference did not reach statistical significance (p ≤ 0.061). CONCLUSION: Observed results raise the importance of better refining the diagnostic protocol for LAR in children. Nasal TSLP and IL-5 levels offer new insights concerning localized allergic inflammation, although the role of nasal sIgE has still to be clarified.

KCa3.1 channel inhibition sensitizes malignant gliomas to temozolomide treatment.

Malignant gliomas are among the most frequent and aggressive cerebral tumors, characterized by high proliferative and invasive indexes. Standard therapy for patients, after surgery and radiotherapy, consists of temozolomide (TMZ), a methylating agent that blocks tumor cell proliferation. Currently, there are no therapies aimed at reducing tumor cell invasion. Ion channels are candidate molecular targets involved in glioma cell migration and infiltration into the brain parenchyma. In this paper we demonstrate that: i) blockade of the calcium-activated potassium channel KCa3.1 with TRAM-34 has co-adjuvant effects with TMZ, reducing GL261 glioma cell migration, invasion and colony forming activity, increasing apoptosis, and forcing cells to pass the G2/M cell cycle phase, likely through cdc2 de-phosphorylation; ii) KCa3.1 silencing potentiates the inhibitory effect of TMZ on glioma cell viability; iii) the combination of TMZ/TRAM-34 attenuates the toxic effects of glioma conditioned medium on neuronal cultures, through a microglia dependent mechanism since the effect is abolished by clodronate-induced microglia killing; iv) TMZ/TRAM-34 co-treatment increases the number of apoptotic tumor cells, and the mean survival time in a syngeneic mouse glioma model (C57BL6 mice implanted with GL261 cells); v) TMZ/TRAM-34 co-treatment reduces cell viability of GBM cells and cancer stem cells (CSC) freshly isolated from patients.Taken together, these data suggest a new therapeutic approach for malignant glioma, targeting both glioma cell proliferating and migration, and demonstrate that TMZ/TRAM-34 co-treatment affects both glioma cells and infiltrating microglia, resulting in an overall reduction of tumor cell progression.

Tumor-associated and immunochemotherapy-dependent long-term alterations of the peripheral blood NK cell compartment in DLBCL patients.

Natural Killer (NK) cells are a key component of tumor immunosurveillance and thus play an important role in rituximab-dependent killing of lymphoma cells via an antibody-dependent cellular cytotoxicity (ADCC) mechanism. We evaluated the phenotypic and functional assets of peripheral blood NK cell subsets in 32 newly-diagnosed diffuse large B-cell lymphoma (DLBCL) patients and in 27 healthy controls. We further monitored long-term modifications of patient NK cells for up to 12 months after rituximab-based immunochemotherapy. At diagnosis, patients showed a higher percentage of CD56dim and CD16+ NK cells, and a higher frequency of GrzB+ cells in CD56dim, CD56bright, and CD16+ NK cell subsets than healthy controls. Conversely, DLBCL NK cell killing and interferon γ (IFNγ) production capability were comparable to those derived from healthy subjects. Notably, NK cells from refractory/relapsed patients exhibited a lower "natural" cytotoxicity. A marked and prolonged therapy-induced reduction of both "natural" and CD16-dependent NK cytotoxic activities was accompanied by the down-modulation of CD16 and NKG2D activating receptors, particularly in the CD56dim subset. However, reduced NK cell killing was not associated with defective lytic granule content or IFNγ production capability. This study firstly describes tumor-associated and therapy-induced alterations of the systemic NK cell compartment in DLBCL patients. As these alterations may negatively impact rituximab-based therapy efficacy, our work may provide useful information for improving immunochemotherapeutic strategies.

Defective microglial development in the hippocampus of Cx3cr1 deficient mice.

Microglial cells participate in brain development and influence neuronal loss and synaptic maturation. Fractalkine is an important neuronal chemokine whose expression increases during development and that can influence microglia function via the fractalkine receptor, CX3CR1. Mice lacking Cx3cr1 show a variety of neuronal defects thought to be the result of deficient microglia function. Activation of CX3CR1 is important for the proper migration of microglia to sites of injury and into the brain during development. However, little is known about how fractalkine modulates microglial properties during development. Here we examined microglial morphology, response to ATP, and K(+) current properties in acute brain slices from Cx3cr1 knockout mice across postnatal hippocampal development. We found that fractalkine signaling is necessary for the development of several morphological and physiological features of microglia. Specifically, we found that the occurrence of an outward rectifying K(+) current, typical of activated microglia, that peaked during the second and third postnatal week, was reduced in Cx3cr1 knockout mice. Fractalkine signaling also influenced microglial morphology and ability to extend processes in response to ATP following its focal application to the slice. Our results reveal the developmental profile of several morphological and physiological properties of microglia and demonstrate that these processes are modulated by fractalkine signaling.

Enriched environment reduces glioma growth through immune and non-immune mechanisms in mice.

Mice exposed to standard (SE) or enriched environment (EE) were transplanted with murine or human glioma cells and differences in tumour development were evaluated. We report that EE exposure affects: (i) tumour size, increasing mice survival; (ii) glioma establishment, proliferation and invasion; (iii) microglia/macrophage (M/Mφ) activation; (iv) natural killer (NK) cell infiltration and activation; and (v) cerebral levels of IL-15 and BDNF. Direct infusion of IL-15 or BDNF in the brain of mice transplanted with glioma significantly reduces tumour growth. We demonstrate that brain infusion of IL-15 increases the frequency of NK cell infiltrating the tumour and that NK cell depletion reduces the efficacy of EE and IL-15 on tumour size and of EE on mice survival. BDNF infusion reduces M/Mφ infiltration and CD68 immunoreactivity in tumour mass and reduces glioma migration inhibiting the small G protein RhoA through the truncated TrkB.T1 receptor. These results suggest alternative approaches for glioma treatment.

Effect of surgery on pancreatic tumor-dependent lymphocyte asset: modulation of natural killer cell frequency and cytotoxic function.

OBJECTIVES: Tumor burden and invasiveness establish a microenvironment that surgery could alter. This study shows a comprehensive analysis of size, dynamics, and function of peripheral lymphocyte subsets in pancreatic cancer patients before and at different times after duodenopancreatectomy. METHODS: Lymphocyte frequency and natural cytotoxicity were evaluated by flow cytometry and in vitro assay on peripheral blood from initial and advanced-stage pancreatic cancer patients before (BS), at day 7 (PS7), and at day 30 (PS30) after surgery. RESULTS: An increase in natural killer (NK) cells and the diminution of B-cells occurred at PS30, whereas cytotoxicity decreased at PS7. The positive correlation between NK frequency and cytotoxicity at BS and PS7 revealed an altered NK behavior. The elevation of NK cell frequency at PS30, an initial defect in CD56bright NK, and the aberrant correlation between NK frequency and cytotoxicity remained significant in advanced-stage patients, whereas the diminution of NK cytotoxicity only affected initial stage patients. CONCLUSIONS: The NK cell functional ability is altered in presurgery patients; duodenopancreatectomy is associated with short-term impairment of NK function and with a long-term NK cell augmentation and reversion of the aberrant NK behavior, which may impact on immunosurveillance against residual cancer.

Increased IL-17, a Pathogenic Link between Hepatosplenic Schistosomiasis and Amyotrophic Lateral Sclerosis: A Hypothesis.

The immune system protects the organism from foreign invaders and foreign substances and is involved in physiological functions that range from tissue repair to neurocognition. However, an excessive or dysregulated immune response can cause immunopathology and disease. A 39-year-old man was affected by severe hepatosplenic schistosomiasis mansoni and by amyotrophic lateral sclerosis. One question that arose was, whether there was a relation between the parasitic and the neurodegenerative disease. IL-17, a proinflammatory cytokine, is produced mainly by T helper-17 CD4 cells, a recently discovered new lineage of effector CD4 T cells. Experimental mouse models of schistosomiasis have shown that IL-17 is a key player in the immunopathology of schistosomiasis. There are also reports that suggest that IL-17 might have an important role in the pathogenesis of amyotrophic lateral sclerosis. It is hypothesized that the factors that might have led to increased IL-17 in the hepatosplenic schistosomiasis mansoni might also have contributed to the development of amyotrophic lateral sclerosis in the described patient. A multitude of environmental factors, including infections, xenobiotic substances, intestinal microbiota, and vitamin D deficiency, that are able to induce a proinflammatory immune response polarization, might favor the development of amyotrophic lateral sclerosis in predisposed individuals.

Trasmembrane chemokines CX3CL1 and CXCL16 drive interplay between neurons, microglia and astrocytes to counteract pMCAO and excitotoxic neuronal death.

Upon noxious insults, cells of the brain parenchyma activate endogenous self-protective mechanisms to counteract brain damage. Interplay between microglia and astrocytes can be determinant to build a physiological response to noxious stimuli arisen from injury or stress, thus understanding the cross talk between microglia and astrocytes would be helpful to elucidate the role of glial cells in endogenous protective mechanisms and might contribute to the development of new strategy to mobilize such program and reduce brain cell death. Here we demonstrate that chemokines CX3CL1 and CXCL16 are molecular players that synergistically drive cross-talk between neurons, microglia and astrocytes to promote physiological neuroprotective mechanisms that counteract neuronal cell death due to ischemic and excitotoxic insults. In an in vivo model of permanent middle cerebral artery occlusion (pMCAO) we found that exogenous administration of soluble CXCL16 reduces ischemic volume and that, upon pMCAO, endogenous CXCL16 signaling restrains brain damage, being ischemic volume reduced in mice that lack CXCL16 receptor. We demonstrated that CX3CL1, acting on microglia, elicits CXCL16 release from glia and this is important to induce neroprotection since lack of CXCL16 signaling impairs CX3CL1 neuroprotection against both in vitro Glu-excitotoxic insult and pMCAO. Moreover the activity of adenosine receptor A3R and the astrocytic release of CCL2 play also a role in trasmembrane chemokine neuroprotective effect, since their inactivation reduces CX3CL1- and CXCL16 induced neuroprotection.

CX3CL1 and CX3CR1 expression in tertiary lymphoid structures in salivary gland infiltrates: fractalkine contribution to lymphoid neogenesis in Sjogren's syndrome.

OBJECTIVES: Primary SS is an autoimmune disease characterized by chronic lymphocytic inflammation and ectopic germinal centre (GC) formation within salivary glands. Fractalkine (CX3CL1), associated with the pathogenesis of RA, is the sole member of the CX3C chemokine (CK) family and acts as an adhesion and chemotactic molecule. The objectives of this work are to determine to what extent CX3CL1 and its receptor CX3CR1 expression might be altered in salivary glands obtained from patients and to establish whether these CKs might be involved in SS ectopic lymphoneogenesis. METHODS: We assessed the presence of CX3CL1 protein in sera by ELISA in 21 patients with primary SS, 11 patients with Sicca syndrome (Sicca), 20 RA patients and 10 blood donors. Histological evaluation was performed on sequential sections of salivary gland tissue. Using TaqMan RT-PCR we studied CX3CL1 and CX3CR1 mRNA expression in salivary gland tissues from a molecular point of view. RESULTS: Increased serum levels of CX3CL1 protein were observed in SS patients compared with controls (P < 0.0001) and in RA patients compared with controls (P < 0.0001), but no difference was found between Sicca patients and controls (P = 0.22). We identified histologically the cells expressing CX3CL1 and CX3CR1 in salivary glands of SS patients and we localized the molecule within tertiary lymphoid structures. Finally, the mRNA levels of the CK and its receptor were up-regulated in SS salivary glands. CONCLUSION: We believe that our findings point to the need for future studies on CX3CL1 and CX3CR1 proteins as contributors to the formation of ectopic GCs and possibly as a new tool in the evaluation and diagnosis of SS.

Functional cross talk between CXCR4 and PDGFR on glioblastoma cells is essential for migration.

Glioblastoma (GBM) is the most common and aggressive form of brain tumor, characterized by high migratory behavior and infiltration in brain parenchyma which render classic therapeutic approach ineffective. The migratory behaviour of GBM cells could be conditioned by a number of tissue- and glioma-derived cytokines and growth factors. Although the pro-migratory action of CXCL12 on GBM cells in vitro and in vivo is recognized, the molecular mechanisms involved are not clearly identified. In fact the signaling pathways involved in the pro-migratory action of CXCL12 may differ in individual glioblastoma and integrate with those resulting from abnormal expression and activation of growth factor receptors. In this study we investigated whether some of the receptor tyrosine kinases commonly expressed in GBM cells could cooperate with CXCL12/CXCR4 in their migratory behavior. Our results show a functional cross-talk between CXCR4 and PDGFR which appears to be essential for GBM chemotaxis.

Modulatory Effect of Gliadin Peptide 10-mer on Epithelial Intestinal CACO-2 Cell Inflammatory Response.

Celiac Disease (CD) is a chronic inflammatory enteropathy, triggered in genetically susceptible individuals by dietary gluten. Gluten is able to elicit proliferation of specific T cells and secretion of inflammatory cytokines in the small intestine. In this study we investigated the possibility that p10-mer, a decapeptide from durum wheat (QQPQDAVQPF), which was previously shown to prevent the activation of celiac peripheral lymphocytes, may exert an inhibitory effect on peptic-tryptic digested gliadin (PT-Gly)-stimulated intestinal carcinoma CACO-2 cells. In these cells, incubated with PT-Gly or p31-43 α-gliadin derived peptide in the presence or in the absence of p10-mer, IRAK1 activation and NF-kB, ERK1/2 and p38 MAPK phosphorylation were measured by immunoblotting, Cyclooxigenase 2 (COX-2) activity by PGE-2 release assay, and production of cytokines in the cell supernatants by ELISA. Our results showed that pre-treatment of CACO-2 cells with p10-mer significantly inhibited IRAK1 activation and NF-kB, ERK1/2 and p38 MAPK phosphorylation, as well as COX-2 activity (i.e. PGE-2 release) and production of the IL-6 and IL-8 pro-inflammatory cytokines, induced by gliadin peptides. These findings demonstrate the inhibitory effect of the p10-mer peptide on inflammatory response in CACO-2 cells. The results of the present study show that this p10-mer peptide can modulate "in vitro" the inflammatory response induced by gliadin peptides, allowing to move towards new therapeutic strategies. Turning off the inflammatory response, may in fact represent a key target in the immunotherapy of celiac disease.