Targeting CXCR4 reverts the suppressive activity of T-regulatory cells in renal cancer

With the intent to identify biomarkers in renal cell carcinoma (RCC) the functional status of T-regulatory cells (Tregs) was investigated in primary RCC. Tregs were isolated from tumoral-(TT), peritumoral tissue-(PT) and peripheral blood-(PB) of 42 primary RCC patients and function evaluated through effector T cells (Teff) proliferation, cytokines release and demethylation of Treg Specific Region (TSDR). The highest value of Tregs was detected in TT with the uppermost amount of effector-Tregs-(CD4+CD25hiFOXP3hiCD45RA-). PB-RCC Tregs efficiently suppress Teff proliferation compared to healthy donor (HD)-Tregs and, at the intrapatient evaluation, TT-derived Tregs were the most suppressive. Higher demethylation TSDR was detected in TT- and PB-RCC Tregs vs HD-Tregs (P <0,001). CXCR4 is highly expressed on Tregs, thus we wished to modulate Tregs function through CXCR4 inhibition. CXCR4 antagonism, elicited by a new peptidic antagonist, Peptide-R29, efficiently reversed Tregs suppression of Teff proliferation. Thus Tregs functional evaluation precisely reflects Tregs status and may be a reliable biomarker of tumoral immune response. In addition, treatment with CXCR4 antagonist, impairing Tregs function, could improve the anticancer immune response, in combination with conventional therapy and/or immunotherapy such as checkpoints inhibitors

Gliadin-Mediated Proliferation and Innate Immune Activation in Celiac Disease Are Due to Alterations in Vesicular Trafficking

Background and Objectives: Damage to intestinal mucosa in celiac disease (CD) is mediated both by inflammation due to adaptive and innate immune responses, with IL-15 as a major mediator of the innate immune response, and by proliferation of crypt enterocytes as an early alteration of CD mucosa causing crypts hyperplasia. We have previously shown that gliadin peptide P31-43 induces proliferation of cell lines and celiac enterocytes by delaying degradation of the active epidermal growth factor receptor (EGFR) due to delayed maturation of endocytic vesicles. IL-15 is increased in the intestine of patients affected by CD and has pleiotropic activity that ultimately results in immunoregulatory cross-talk between cells belonging to the innate and adaptive branches of the immune response. Aims of this study were to investigate the role of P31-43 in the induction of cellular proliferation and innate immune activation. Methods/Principal Findings: Cell proliferation was evaluated by bromodeoxyuridine (BrdU) incorporation both in CaCo-2 cells and in biopsies from active CD cases and controls. We used real-time PCR to evaluate IL-15 mRNA levels and FACS as well as ELISA and Western Blot (WB) analysis to measure protein levels and distribution in CaCo-2 cells. Gliadin and P31-43 induce a proliferation of both CaCo-2 cells and CD crypt enterocytes that is dependent on both EGFR and IL-15 activity. In CaCo-2 cells, P31-43 increased IL-15 levels on the cell surface by altering intracellular trafficking. The increased IL-15 protein was bound to IL15 receptor (IL-15R) alpha, did not require new protein synthesis and functioned as a growth factor. Conclusion: In this study, we have shown that P31-43 induces both increase of the trans-presented IL-15/IL5R alpha complex on cell surfaces by altering the trafficking of the vesicular compartments as well as proliferation of crypt enterocytes with consequent remodelling of CD mucosa due to a cooperation of IL-15 and EGFR

New CXCR4 Antagonist Peptide R (Pep R) Improves Standard Therapy in Colorectal Cancer

he chemokine receptor CXCR4 is overexpressed and functional in colorectal cancer. To investigate the role of CXCR4 antagonism in potentiating colon cancer standard therapy, the new peptide CXCR4 antagonist Peptide R (Pep R) was employed. Human colon cancer HCT116 xenograft-bearing mice were treated with chemotherapeutic agents (CT) 5-Fluorouracil (5FU) and oxaliplatin (OX) or 5FU and radio chemotherapy (RT-CT) in the presence of Pep R. After two weeks, CT plus Pep R reduced by 4-fold the relative tumor volume (RTV) as compared to 2- and 1.6-fold reductions induced, respectively, by CT and Pep R. In vitro Pep R addition to CT/RT-CT impaired HCT116 cell growth and further reduced HCT116 and HT29 clonal capability. Thus, the hypothesis that Pep R could target the epithelial mesenchyme transition (EMT) process was evaluated. While CT decreased ECAD and increased ZEB-1 and CD90 expression, the addition of Pep R restored the pretreatment expression. In HCT116 and HT29 cells, CT/RT-CT induced a population of CD133+CXCR4+ cells, supposedly a stem-resistant cancer cell population, while Pep R reduced it. Taken together, the results showed that targeting CXCR4 ameliorates the effect of treatment in colon cancer through inhibition of cell growth and reversal of EMT treatment-induced markers, supporting further clinical studies

Rapid targeted mutational analysis of human tumours: a clinical platform to guide personalized cancer medicine

Targeted cancer therapy requires the rapid and accurate identification of genetic abnormalities predictive of therapeutic response. We sought to develop a high-throughput genotyping platform that would allow prospective patient selection to the best available therapies, and that could readily and inexpensively be adopted by most clinical laboratories. We developed a highly sensitive multiplexed clinical assay that performs very well with nucleic acid derived from formalin fixation and paraffin embedding (FFPE) tissue, and tests for 120 previously described mutations in 13 cancer genes. Genetic profiling of 250 primary tumours was consistent with the documented oncogene mutational spectrum and identified rare events in some cancer types. The assay is currently being used for clinical testing of tumour samples and contributing to cancer patient management. This work therefore establishes a platform for real-time targeted genotyping that can be widely adopted. We expect that efforts like this one will play an increasingly important role in cancer management

Gliadin Peptide P31-43 Localises to Endocytic Vesicles and Interferes with Their Maturation

BACKGROUND: Celiac Disease (CD) is both a frequent disease (1:100) and an interesting model of a disease induced by food. It consists in an immunogenic reaction to wheat gluten and glutenins that has been found to arise in a specific genetic background; however, this reaction is still only partially understood. Activation of innate immunity by gliadin peptides is an important component of the early events of the disease. In particular the so-called "toxic" A-gliadin peptide P31-43 induces several pleiotropic effects including Epidermal Growth Factor Receptor (EGFR)-dependent actin remodelling and proliferation in cultured cell lines and in enterocytes from CD patients. These effects are mediated by delayed EGFR degradation and prolonged EGFR activation in endocytic vesicles. In the present study we investigated the effects of gliadin peptides on the trafficking and maturation of endocytic vesicles. METHODS/PRINCIPAL FINDINGS: Both P31-43 and the control P57-68 peptide labelled with fluorochromes were found to enter CaCo-2 cells and interact with the endocytic compartment in pulse and chase, time-lapse, experiments. P31-43 was localised to vesicles carrying early endocytic markers at time points when P57-68-carrying vesicles mature into late endosomes. In time-lapse experiments the trafficking of P31-43-labelled vesicles was delayed, regardless of the cargo they were carrying. Furthermore in celiac enterocytes, from cultured duodenal biopsies, P31-43 trafficking is delayed in early endocytic vesicles. A sequence similarity search revealed that P31-43 is strikingly similar to Hrs, a key molecule regulating endocytic maturation. A-gliadin peptide P31-43 interfered with Hrs correct localisation to early endosomes as revealed by western blot and immunofluorescence microscopy. CONCLUSIONS: P31-43 and P57-68 enter cells by endocytosis. Only P31-43 localises at the endocytic membranes and delays vesicle trafficking by interfering with Hrs-mediated maturation to late endosomes in cells and intestinal biopsies. Consequently, in P31-43-treated cells, Receptor Tyrosine Kinase (RTK) activation is extended. This finding may explain the role played by gliadin peptides in inducing proliferation and other effects in enterocytes from CD biopsies

Tau association with synaptic vesicles causes presynaptic dysfunction

Tau is implicated in more than 20 neurodegenerative diseases, including Alzheimer's disease. Under pathological conditions, Tau dissociates from axonal microtubules and missorts to pre- and postsynaptic terminals. Patients suffer from early synaptic dysfunction prior to Tau aggregate formation, but the underlying mechanism is unclear. Here we show that pathogenic Tau binds to synaptic vesicles via its N-terminal domain and interferes with presynaptic functions, including synaptic vesicle mobility and release rate, lowering neurotransmission in fly and rat neurons. Pathological Tau mutants lacking the vesicle binding domain still localize to the presynaptic compartment but do not impair synaptic function in fly neurons. Moreover, an exogenously applied membrane-permeable peptide that competes for Tau-vesicle binding suppresses Tau-induced synaptic toxicity in rat neurons. Our work uncovers a presynaptic role of Tau that may be part of the early pathology in various Tauopathies and could be exploited therapeutically.status: publishe

Relationship between proliferative effects and activation of innate immunity induced by gliadin

Celiac Disease (CD) is both a frequent disease (1:100) and an interesting model of a disease induced by food. It consists in an immunogenic reaction to wheat gluten and glutenins that has been found to arise in a specific genetic background; however, this reaction is still only partially understood. Activation of innate immunity by gliadin peptides is an important component of the early events of the disease. In particular the so-called “toxic” A-gliadin peptide P31-43 induces several pleiotropic effects including Epidermal Growth Factor Receptor (EGFR)-dependent actin remodelling and proliferation in cultured cell lines and in enterocytes from CD patients. These effects are mediated by delayed EGFR degradation and prolonged EGFR activation in endocytic vesicles. In the present study we investigated the effects of gliadin peptides on the trafficking and maturation of endocytic vesicles. We observed that both P31-43 and the control P57-68 peptide labelled with fluorochromes were found to enter CaCo-2 cells and interact with the endocytic compartment in pulse and chase, time-lapse, experiments. P31-43 was localised to vesicles carrying early endocytic markers at time points when P57-68-carrying vesicles mature into late endosomes. In time-lapse experiments the trafficking of P31-43-labelled vesicles was delayed, regardless of the cargo they were carrying. Furthermore in celiac enterocytes, from cultured duodenal biopsies, P31-43 trafficking is delayed in early endocytic vesicles. A sequence similarity search revealed that P31-43 is strikingly similar to Hrs, a key molecule regulating endocytic maturation. A-gliadin peptide P31-43 interfered with Hrs correct localisation to early endosomes as revealed by western blot and immunofluorescence microscopy. P31-43 and P57-68 enter cells by endocytosis. Only P31-43 localises at the endocytic membranes and delays vesicle trafficking by interfering with Hrs-mediated maturation to late endosomes in cells and intestinal biopsies. Consequently, in P31-43-treated cells, Receptor Tyrosin Kinase (RTK) activation is extended. This finding may explain the role played by gliadin peptides in inducing proliferation and other effects in enterocytes from CD biopsies. Damage to the intestinal mucosa in celiac disease is mediated both by inflammation due to the adaptive and innate immune responses, with IL-15 as a major mediator of the innate immune response, and by proliferation of crypt enterocytes as an early alteration of CD mucosa causing crypts hyperplasia.We investigated the role of P31-43 in the induction of cellular proliferation and innate immune activation. In this work it has been shown that gliadin and P31-43 induce a proliferation of both CaCo2 cells and CD crypt enterocytes that is dependent on both EGFR and IL-15 activity. In CaCo-2 cells, P31-43 increased IL-15 levels on the cell surface by interfering with its intracellular trafficking. The increased IL-15 protein was linked to IL15 receptor (IL-15R) alpha, which did not require new protein synthesis and therefore functioned as a growth factor. In this study, we have shown that P31-43 induces both an increase of the trans-presented IL-15/IL5R alpha complex on cell surfaces by interfering with trafficking of vesicular compartments as well as a proliferation of crypt enterocytes with consequent remodelling of CD mucosa due to a cooperation of IL-15 and EGFR. Celiac disease is condition where the regulation of the mucosal immune response to dietary gliadin might be altered. The transcription factor Foxp3 has been identified as a marker of a subset of regulatory T cells (Treg). In this study we have investigated the presence and the suppressive function of Treg cells in the celiac small intestinal mucosa, their correlation with the disease state and the inducibility by gliadin in an organ culture system; moreover, we tried to define whether interleukin 15, overexpressed in CD, could influence the regulatory activity of such cells. We observed a higher density of CD4+CD25+Foxp3+ T cells were seen in duodenal biopsies from active CD patients in comparison to treated CD and non-CD controls. In coculture CD4+CD25+ T cells were functionally suppressive, but their activity was impaired by IL-15. Cells from CD subjects showed increased sensitivity to the IL15 action likely due to enhanced expression of IL15 receptor. Finally, we demonstrated an expansion of Foxp3 in treated CD mucosa following in vitro challenge with gliadin. These data suggest that CD4+CD25+Foxp3+ T cells are induced in situ by gliadin. However, their suppressor capacity might be impaired in vivo by IL-15, this phenomenon contributing to maintain and expand the local inflammatory response in CD

M.V. Barone, M. Nanayakkara, D. Zanzi, S. Santagata, G. Lania, V. Discepolo, M. Ten-Eikelder, S. Auricchio

Background and AimsWe previously observed that A-gliadin peptide P31-43 induces effects similar to Epidermal growthfactor (EGF) both in cultured cell lines and in enterocytes from celiac disease (CD) patients. Wealso showed that the effect is mediated by delayed EGF degradation and prolonged EGF receptor(EGFR) activation in endocytic vesicles. Here we address the molecular mechanisms underlyinggliadin peptide effects on trafficking and maturation of vesicles responsible for EGFR endocytosis.MethodsA sequence similarity search revealed that P31-43 is strikingly similar to a region of Hrs, a keymolecule involved in endocytic maturation. Western blot and immunofluorescence microscopy wereused to determine Hrs localization to endocytic vesicles and cytosol. Pulse and chase labelling intime-lapse experiments allowed to follow uptake and sub-cellular localization of gliadin peptides inCaCo 2 cells and enterocytes from CD patients and controls.ResultsA-gliadin peptide P31-43 interferes with Hrs localization to early endosomes. Both P31-43 and thecontrol P56-68 peptide enter CaCo 2 cells and interact with the endocytic compartment, but P31-43 is localized to vesicles carrying early endocytic markers at time points when P56-68-carryingvesicles mature into late endosomes. Dynamic analysis shows that P31-43 labelled vesicles areslowed down in time-lapse experiments. The effect is independent of the cargo they carry: dextrancontaining vesicles, behave similarly to EGFR containing ones. Markers of recycling pathwayTrasferrin receptor and Lamp, are increased on the surface of P31-43 treated cells together withEGFR. Gliadin peptide P31-43 enters epithelial cells and colocalize with EEA1 both in CD biopsiesand controls coltured for 24 hours. Pulse and chase experiments show a delay of trafficking of P31-43 peptide in EEA1 positive vesicles only in CD biopsies, but not in controlsConclusionsGliadin peptide P31-43 delays vesicle trafficking by interfering with Hrs mediated maturation to lateendosomes and also promotes the recycling pathway. As a consequence, in P31-43 treated cells,EGFR activation is extended, more transferrin and EGFR receptors find their way to the cellsurface. In CD biopsies trafficking of this peptide is delayed. This may help explaining the roleplayed by gliadin peptides in CD pathogenesis