Farnesoid X Receptor and its ligands inhibit the function of platelets

Objective - While initially seemingly paradoxical due to the lack of nucleus, platelets possess a number of transcription factors that regulate their function through DNA-independent mechanisms. These include the Farnesoid X Receptor (FXR), a member of the superfamily of ligand-activated transcription factors that has been identified as a bile acid receptor. In this study, we show that FXR is present in human platelets and FXR ligands, GW4064 and 6-ECDCA, modulate platelet activation nongenomically. Approach and Results - FXR ligands inhibited the activation of platelets in response to stimulation of collagen or thrombin receptors, resulting in diminished intracellular calcium mobilization and secretion, fibrinogen binding and aggregation. Exposure to FXR ligands also reduced integrin alphaIIbbeta3 outside-in signaling and thereby reduced the ability of platelets to spread and to stimulate clot retraction. FXR function in platelets was found to be associated with the modulation of cGMP levels in platelets and associated downstream inhibitory signaling. Platelets from FXR-deficient mice were refractory to the actions of FXR agonists on platelet function and cyclic nucleotide signaling, firmly linking the non-genomic actions of these ligands to the FXR receptor. Conclusion – This study provides support for the ability of FXR ligands to modulate platelet activation. The athero-protective effects of GW4064, with its novel antiplatelet effects, indicate FXR as a potential target for prevention of athero-thrombotic disease

Cholangiopathy and biliary fibrosis in Cyp2c70-deficient mice are fully reversed by ursodeoxycholic acid

BACKGROUND AND AIMS: Bile acids (BAs) aid intestinal fat absorption and exert systemic actions by receptor-mediated signaling. BA receptors have been identified as drug targets for liver diseases. Yet, differences in BA metabolism between humans and mice hamper translation of pre-clinical outcomes. Cyp2c70-ablation in mice prevents synthesis of mouse/rat-specific muricholic acids (MCAs), but potential (patho)physiological consequences of their absence are unknown. We therefore assessed age- and gender-dependent effects of Cyp2c70-deficiency in mice. METHODS: The consequences of Cyp2c70-deficiency were assessed in male and female mice at different ages. RESULTS: Cyp2c70-/- mice were devoid of MCAs and showed high abundances of chenodeoxycholic and lithocholic acids. Cyp2c70-deficiency profoundly impacted microbiome composition. Bile flow and biliary BA secretion were normal in Cyp2c70-/- mice of both sexes. Yet, the pathophysiological consequences of Cyp2c70-deficiency differed considerably between sexes. Three-week old male Cyp2c70-/- mice showed high plasma BAs and transaminases, which spontaneously decreased thereafter to near-normal levels. Only mild ductular reactions were observed in male Cyp2c70-/- mice up to 8 months of age. In female Cyp2c70-/- mice, plasma BAs and transaminases remained substantially elevated with age, gut barrier function was impaired and bridging fibrosis was observed at advanced age. Addition of 0.1% ursodeoxycholic acid to the diet fully normalized hepatic and intestinal functions in female Cyp2c70-/- mice. CONCLUSION: Cyp2c70-/- mice show transient neonatal cholestasis and develop cholangiopathic features that progress to bridging fibrosis in females only. These consequences of Cyp2c70-deficiency are restored by treatment with UDCA, indicating a role of BA hydrophobicity in disease development

A novel IgE antibody targeting the prostate-specific antigen as a potential prostate cancer therapy

Prostate cancer (PCa) is the second leading cause of cancer deaths in men in the United States. The prostate-specific antigen (PSA), often found at high levels in the serum of PCa patients, has been used as a marker for PCa detection and as a target of immunotherapy. The murine IgG1 monoclonal antibody AR47.47, specific for human PSA, has been shown to enhance antigen presentation by human dendritic cells and induce both CD4 andCD8 T-cell activation when complexed with PSA. In this study, we explored the properties of a novel mouse/human chimeric anti-PSA IgE containing the variable regions of AR47.47 as a potential therapy for PCa. Our goal was to take advantage of the unique properties of IgE in order to trigger immune activation against PCa.Fil: Daniels-Wells, Tracy R. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América;Fil: Helguera, Gustavo Fernando. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Departamento de Tecnologia Farmaceutica; Argentina; University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América;Fil: Leuchter, Richard K. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América;Fil: Quintero, Rafael. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América;Fil: Kozman, Maggie. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América;Fil: Rodríguez, José A.. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América; University of California. The Molecular Biology Institute; Estados Unidos de América;Fil: Ortiz-Sánchez, E. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América; Biomedical Research in Cancer. Basic Research Division. National Institute of Cancerology; Mexico.;Fil: Martínez-Maza, Otonel. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América;Fil: Schultes, Brigit C.. Advanced Immune Therapeutics; Estados Unidos de América;Fil: Nicodemus Christopher. Advanced Immune Therapeutics; Estados Unidos de América;Fil: Penichet, Manuel. University of California. David Geffen School of Medicine. Department of Surgery. Division of Surgical Oncology; Estados Unidos de América; University of California. The Molecular Biology Institute; Estados Unidos de América

Targeting HER2/neu with a fully human IgE to harness the allergic reaction against cancer cells

Breast and ovarian cancer are two of the leading causes of cancer deaths among women in the United States. Overexpression of the HER2/neu oncoprotein has been reported in patients affected with breast and ovarian cancers, and is associated with poor prognosis. To develop a novel targeted therapy for HER2/neu expressing tumors, we have constructed a fully human IgE with the variable regions of the scFv C6MH3-B1 specific for HER2/neu. This antibody was expressed in murine myeloma cells and was properly assembled and secreted. The Fc region of this antibody triggers in vitro degranulation of rat basophilic cells expressing human FcεRI (RBL SX-38) in the presence of murine mammary carcinoma cells that express human HER2/neu (D2F2/E2), but not the shed (soluble) antigen (ECDHER2) alone. This IgE is also capable of inducing passive cutaneous anaphylaxis in a human FcεRIα transgenic mouse model, in the presence of a cross-linking antibody, but not in the presence of soluble ECDHER2. Additionally, IgE enhances antigen presentation in human dendritic cells and facilitates cross-priming, suggesting that the antibody is able to stimulate a secondary T-cell anti-tumor response. Furthermore, we show that this IgE significantly prolongs survival of human FcεRIα transgenic mice bearing D2F2/E2 tumors. We also report that the anti-HER2/neu IgE is well tolerated in a preliminary study conducted in Macaca fascicularis (cynomolgus) monkeys. In summary, our results suggest that this IgE should be further explored as a potential therapeutic against HER2/neu overexpressing tumors, such as breast and ovarian cancers.Fil: Daniels, Tracy R.. University of California at Los Angeles; Estados UnidosFil: Leuchter, Richard K.. University of California at Los Angeles; Estados UnidosFil: Quintero, Rafaela. University of California; Estados UnidosFil: Helguera, Gustavo Fernando. University of California at Los Angeles; Estados Unidos. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, José A.. University of California at Los Angeles; Estados UnidosFil: Martínez Maza, Otoniel. University of California at Los Angeles; Estados UnidosFil: Schultes, Birgit C.. Advanced Immune Therapeutics, Inc.; Estados Unidos. Momenta Pharmaceuticals, Inc.; Estados UnidosFil: Nicodemus, Christopher F.. Advanced Immune Therapeutics, Inc.; Estados UnidosFil: Penichet, Manuel L.. University of California at Los Angeles; Estados Unido

Metabolic and Innate Immune Cues Merge into a Specific Inflammatory Response via the UPR

Erratum in : Metabolic and Innate Immune Cues Merge into a Specific Inflammatory Response via the UPR. [Cell. 2019]International audienceInnate immune responses are intricately linked with intracellular metabolism of myeloid cells. Toll-likereceptor (TLR) stimulation shifts intracellular metabolism toward glycolysis, while anti-inflammatorysignals depend on enhanced mitochondrial respiration. How exogenous metabolic signals affect theimmune response is unknown. We demonstrate that TLR-dependent responses of dendritic cells (DC)are exacerbated by a high fatty acid (FA) metabolic environment. FA suppress the TLR-inducedhexokinase activity and perturb tricarboxylic acid cycle metabolism. These metabolic changesenhance mitochondrial reactive oxygen species (mtROS) production and, in turn, the unfolded proteinresponse (UPR) leading to a distinct transcriptomic signature, with IL-23 as hallmark. Interestingly,chemical or genetic suppression of glycolysis was sufficient to induce this specific immune response.Conversely, reducing mtROS production or DC-specific deficiency in XBP1 attenuated IL-23expression and skin inflammation in an IL-23-dependent model of psoriasis. Thus, fine-tuning of innateimmunity depends on optimization of metabolic demands and minimization of mtROS-induced UPR

Cellular and molecular changes and immune response in the intestinal mucosa during Trichinella spiralis early infection in rats

Background:: The main targets of the host's immune system in Trichinella spiralis infection are the adult worms (AW), at the gut level, and the migrant or newborn larvae (NBL), at systemic and pulmonary levels. Most of the studies carried out in the gut mucosa have been performed on the Payer's patches and/or the mesenteric lymph nodes but not on the lamina propria, therefore, knowledge on the gut immune response against T. spiralis remains incomplete. Methods: This study aimed at characterizing the early mucosal immune response against T. spiralis, particularly, the events taking place between 1 and 13 dpi. For this purpose, Wistar rats were orally infected with muscle larvae of T. spiralis and the humoral and cellular parameters of the gut immunity were analysed, including the evaluation of the ADCC mechanism exerted by lamina propria cells. Results: A marked inflammation and structural alteration of the mucosa was found. The changes involved an increase in goblet cells, eosinophils and mast cells, and B and T lymphocytes, initially displaying a Th1 profile, characterised by the secretion of IFN-γand IL-12, followed by a polarization towards a Th2 profile, with a marked increase in IgE, IgG1, IL-4, IL-5 and IL-13 levels, which occurred once the infection was established. In addition, the helminthotoxic activity of lamina propria cells demonstrated the role of the intestine as a place of migrant larvae destruction, indicating that not all the NBLs released in the gut will be able to reach the muscles. Conclusions: The characterization of the immune response triggered in the gut mucosa during T. spiralis infection showed that not only an effector mechanism is directed toward the AW but also towards the NBL as a cytotoxic activity was observed against NBL exerted by lamina propria cells.Fil: Saracino, María Priscila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Vila, Cecilia Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Cohen, Melina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Gentilini, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Falduto, Guido Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Calcagno, Marcela Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Roux, Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiológicas; ArgentinaFil: Venturiello, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; ArgentinaFil: Malchiodi, Emilio Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentin

Probiotic Microbes Sustain Youthful Serum Testosterone Levels and Testicular Size in Aging Mice

The decline of circulating testosterone levels in aging men is associated with adverse health effects. During studies of probiotic bacteria and obesity, we discovered that male mice routinely consuming purified lactic acid bacteria originally isolated from human milk had larger testicles and increased serum testosterone levels compared to their age-matched controls. Further investigation using microscopy-assisted histomorphometry of testicular tissue showed that mice consuming Lactobacillus reuteri in their drinking water had significantly increased seminiferous tubule cross-sectional profiles and increased spermatogenesis and Leydig cell numbers per testis when compared with matched diet counterparts This showed that criteria of gonadal aging were reduced after routinely consuming a purified microbe such as L. reuteri. We tested whether these features typical of sustained reproductive fitness may be due to anti-inflammatory properties of L. reuteri, and found that testicular mass and other indicators typical of old age were similarly restored to youthful levels using systemic administration of antibodies blocking pro-inflammatory cytokine interleukin-17A. This indicated that uncontrolled host inflammatory responses contributed to the testicular atrophy phenotype in aged mice. Reduced circulating testosterone levels have been implicated in many adverse effects; dietary L. reuteri or other probiotic supplementation may provide a viable natural approach to prevention of male hypogonadism, absent the controversy and side-effects of traditional therapies, and yield practical options for management of disorders typically associated with normal aging. These novel findings suggest a potential high impact for microbe therapy in public health by imparting hormonal and gonad features of reproductive fitness typical of much younger healthy individuals.National Institutes of Health (U.S.) (Grant P30-ES002109)National Institutes of Health (U.S.) (Grant U01 CA164337)National Institutes of Health (U.S.) (Grant RO1CA108854

Epithelial damage and tissue γδ T cells promote a unique tumor-protective IgE response

IgE is an ancient and conserved immunoglobulin isotype with potent immunological function. Nevertheless, the regulation of IgE responses remains an enigma, and evidence of a role for IgE in host defense is limited. Here we report that topical exposure to a common environmental DNA-damaging xenobiotic initiated stress surveillance by γδTCR+ intraepithelial lymphocytes that resulted in class switching to IgE in B cells and the accumulation of autoreactive IgE. High-throughput antibody sequencing revealed that γδ T cells shaped the IgE repertoire by supporting specific variable-diversity-joining (VDJ) rearrangements with unique characteristics of the complementarity-determining region CDRH3. This endogenous IgE response, via the IgE receptor FcεRI, provided protection against epithelial carcinogenesis, and expression of the gene encoding FcεRI in human squamous-cell carcinoma correlated with good disease prognosis. These data indicate a joint role for immunosurveillance by T cells and by B cells in epithelial tissues and suggest that IgE is part of the host defense against epithelial damage and tumor development

AllergoOncology: Danger signals in Allergology and Oncology. A European Academy of Allergy and Clinical Immunology (EAACI) Position Paper

The immune system interacts with many nominal ‘danger’ signals, endogenous danger-associated (DAMP), exogenous pathogen (PAMP) and allergen (AAMP)-associated molecular patterns. The immune context under which these are received can promote or prevent immune activating or inflammatory mechanisms and may orchestrate diverse immune responses in allergy and cancer. Each can act either by favouring a respective pathology or by supporting the immune response to confer protective effects, depending on acuity or chronicity. In this Position Paper under the collective term danger signals or DAMPs, PAMPs and AAMPs, we consider their diverse roles in allergy and cancer and the connection between these in AllergoOncology. We focus on their interactions with different immune cells of the innate and adaptive immune system and how these promote immune responses with juxtaposing clinical outcomes in allergy and cancer. While danger signals present potential targets to overcome inflammatory responses in allergy, these may be reconsidered in relation to a history of allergy, chronic inflammation and autoimmunity linked to the risk of developing cancer, and with regard to clinical responses to anti-cancer immune and targeted therapies. Cross-disciplinary insights in AllergoOncology derived from dissecting clinical phenotypes of common danger signal pathways may improve allergy and cancer clinical outcomes