L’inhibition HDAC induite par le valproate améliore la cytotoxicité directe des monocytes contre les cellules de mésothéliome pleural malin

Malignant pleural mesothelioma (MPM) is a rare cancer affecting mesothelial cells in the pleura. MPM is incurable and treatments only prolong patient’s survival by a few months. Monocytes are innate immunity cells that constitute the first line of defence against tumor cells. In MPM, monocytes exert immunosuppressive functions through the tumor-associated macrophages (TAMs) and the monocyte myeloid-derived suppressor cells (M-MDSCs). Their presence is associated to a bad prognosis in MPM patients. Despite their immunosuppressive functions, monocytes are also able to exert antitumor functions through phagocytosis, antibody-dependent cell-mediated cytotoxicity, cytokine and reactive substance production. The objectives of the thesis consist, on one side, to study the cytotoxic activity of monocytes against MPM cells and, on the other side, to modulate this activity by means of epigenetic regulators. Results show that monocytes exert a cytotoxic activity against MPM cells. In addition, monocyte treatment with VPA, a histone deacetylase inhibitor, significantly increases monocyte migration, their aggregation to tumor cells and their cytotoxicity against MPM cells. Finally, the molecular mechanisms of VPA involve a downregulation of the membrane receptors associated with the M2 phenotype, including CD163, CD206 and CD209. Monocyte treatment with VPA may thus be explored as a novel approach to improve MPM therapy

HDAC Inhibition with Valproate Improves Direct Cytotoxicity of Monocytes against Mesothelioma Tumor Cells

peer reviewedThe composition of the tumor microenvironment (TME) mediates the outcome of chemo- and immunotherapies in malignant pleural mesothelioma (MPM). Tumor-associated macrophages (TAMs) and monocyte myeloid-derived immunosuppressive cells (M-MDSCs) constitute a major fraction of the TME. As central cells of the innate immune system, monocytes exert well-characterized functions of phagocytosis, cytokine production, and antibody-dependent cell-mediated cytotoxicity (ADCC). The objective of this study was to evaluate the ability of monocytes to exert a direct cytotoxicity by cell-to-cell contact with MPM cells. The experimental model is based on cocultures between human blood-derived monocytes sorted by negative selection and mesothelioma cell lines. Data show (i) that blood-derived human monocytes induce tumor cell death by direct cell-to-cell contact, (ii) that VPA is a pharmacological enhancer of this cytotoxic activity, (iii) that VPA increases monocyte migration and their aggregation with MPM cells, and (iv) that the molecular mechanisms behind VPA modulation of monocytes involve a downregulation of the membrane receptors associated with the M2 phenotype, i.e., CD163, CD206, and CD209. These conclusions, thus, broaden our understanding about the molecular mechanisms involved in immunosurveillance of the tumor microenvironment and open new prospects for further improvement of still unsatisfactory MPM therapies

BLV: Lessons on vaccine development

Vaccination against retroviruses is a challenge because of their ability to stably integrate into the host genome, undergo long-term latency in a proportion of infected cells and thereby escape immune response. Since clearance of the virus is almost impossible once infection is established, the primary goal is to achieve sterilizing immunity. Besides efficacy, safety is the major issue since vaccination has been associated with increased infection or reversion to pathogenicity. In this review, we discuss the different issues that we faced during the development of an efficient vaccine against bovine leukemia virus (BLV). We summarize the historical failures of inactivated vaccines, the efficacy and safety of a live-attenuated vaccine and the economical constraints of further industrial development.Fil: Abdala, Alejandro Ariel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Alvarez, Irene. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Brossel, Hélène. Université de Liège; BélgicaFil: Calvinho, Luis Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Carignano, Hugo Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Franco, Lautaro Nahuel. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Gazon, Hélène. Université de Liège; BélgicaFil: Gillissen, Christelle. Université de Liège; BélgicaFil: Hamaidia, Malik. Université de Liège; BélgicaFil: Hoyos, Clotilde. Université de Liège; BélgicaFil: Jacques, Jean Rock. Université de Liège; BélgicaFil: Joris, Thomas. Université de Liège; BélgicaFil: Laval, Florent. Université de Liège; BélgicaFil: Petersen Cruceño, Marcos Iván. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Porquet, Florent. Université de Liège; BélgicaFil: Porta, Natalia Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Ruiz, Vanesa. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Safari, Roghaiyeh. Université de Liège; BélgicaFil: Suárez Archilla, Guillermo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Trono, Karina Gabriela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Gastronómicas. Instituto de Virología E Innovaciones Tecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Willems, Luc. Université de Liège; Bélgic

Contribution of lysine deacetylases to the therapy of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare cancer arising from mesothelial cells from the pleura. The first line chemotherapy of the epithelioid subtype of MPM is based on a combined regimen of cisplatin and an antifolate (pemetrexed). Recently, immunotherapy with two checkpoint inhibitors (PD-1, nivolumab and CTLA-4, ipilimumab) showed promising results for the sarcomatoid subtype. Despite this major breakthrough, the median overall survival of patients only reached 18.1 months, compared to 14 months in standard chemotherapy. With an objective response rate of 40%, only a subset of patients benefits from immunotherapy. Therefore, options for second line treatment are still mandatory. We previously proposed a therapy based on the combination of a topoisomerase inhibitor (doxorubicin) and a lysine deacetylase inhibitor (valproate, VPA) (Scherpereel et al, European Respiratory Journal 37:129-135). We identified one of the key determinants that modulates the chemoresistance (Staumont et al, Cancers 12:1484). In this study, we aimed to further investigate the mechanisms involved by analyzing the effect of VPA on the tumor microenvironment and more particularly on the interactions between monocytes and tumor cells. We showed that VPA affects the viability of doxorubicin-treated mesothelioma cells and promotes their apoptosis. The use of caspase and calpeptin inhibitors demonstrated that apoptosis occurs through a caspase-dependent mechanism involving both intrinsic and extrinsic pathway. Western blot analysis revealed that the combination of VPA and doxorubicin increases the expression of clived-Bid, Bax and cytochrome c while decreasing the expression of Bcl-2 and Bcl-XL. Transcriptomic analysis unveiled that epithelioid mesothelioma cells express more p21, Fas, Bbc3 and TP53INP1 upon treatment compared to the sarcomatoid subtype. To investigate the role of the microenvironment, we designed two models to study the influence of tumor-associated monocytes. Mesothelioma cells were co-cultured with THP-1 monocytes differentiated in presence of PMA. Flow cytometry, confocal microscopy and live imaging demonstrated that THP-1-derived monocytes are able to interact and kill tumor cells. Furthermore, VPA promotes the interaction between monocytes and tumor cells and fosters the cytotoxic activity of monocytes. In contrast to PMA, VPA does not affect the motility of THP-1 monocytes. These observations were validated and extended to primary monocytes isolated from peripheral blood. Increased cytotoxicity of primary monocytes is correlated with a reduced frequency of CD16+ cells. In this model, VPA augments the average speed of primary monocytes. Finally, RNA sequencing highlighted the key mechanisms involved in monocyte antitumor activity. In conclusion, we demonstrate that VPA directly affects the survival of tumor cells and indirectly modulates the cytotoxic activity of monocytes in the microenvironment

Les monocytes possèdent une activité cytotoxique directe envers les cellules de mésothéliome pleural malin

Parmi les symptômes du mésothéliome, les effusions pleurales impactent significativement la qualité de vie des patients. Ce liquide pleural est infiltré par plusieurs types cellulaires, dont notamment des lymphocytes CD4+ et CD8+, des macrophages ou des monocytes. Le rôle de ces cellules dans les mécanismes associés à la dynamique tumorale est imparfaitement compris. L’environnement tumoral favorise notamment la différenciation de monocytes en macrophages associés aux tumeurs (TAM). L’infiltration de ces TAMs dans les tumeurs est corrélée à un mauvais pronostic du patient. Nous nous sommes intéressés à l’interaction des monocytes avec les cellules de mésothéliome pleural malin, indépendamment de leur différenciation en macrophages. En particulier, nous avons étudié l'activité cytotoxique directe des monocytes envers des cellules de mésothéliome. Des cocultures de la lignée monocytaire THP-1 avec des cellules M14K et ZL34 ont été analysées par cytométrie en flux et microscopie Incucyte. Les résultats démontrent que les monocytes interagissent avec les cellules de mésothéliome et exercent une activité cytotoxique par contact direct. L'interférence ARN montre par ailleurs que ce mécanisme implique la méthyltransférase EZH2 du complexe PRC2 et la déméthylase JMJD3. Des expériences actuellement en cours visent à étudier ce phénomène dans des cultures de monocytes primaires isolées du sang périphérique

Endocrine and Metabolic Biomarkers Predicting Early Childhood Obesity Risk

There is growing evidence of long-term effects of early dietary intervention in infancy on later obesity risk. Many studies showed reduced risk of obesity with breastfeeding in infancy, which could be related to the reduced protein intake with human milk compared to infant formula. In a randomized controlled trial (Childhood Obesity Project), we were able to show that infant formula with reduced protein content results in lower BMI both at 2 and 6 years. These effects seem to be mediated mainly by branched-chain amino acids which stimulate the insulin-like growth factor (IGF)-1 axis and insulin release. In this trial, we also showed an influence of high-protein diet on larger kidney size, which seems to be partly explained by a significant effect of free IGF-1 on kidney volume. The IGF-1 axis was shown to regulate early growth, adipose tissue differentiation and early adipogenesis in animals and in humans. Leptin and adiponectin can also be regarded as important endocrine regulators of obesity. These markers were tested in observational studies. Leptin seems to be closely correlated with BMI but changes in adiponectin require further exploration. Still, there is a lack of good data or some results are contradictory to indicate the role of either leptin or adiponectin in infancy for determining later obesity risk.0SCOPUS: ar.kinfo:eu-repo/semantics/publishe