Identification and Characterisation of the Murine Homologue of the Gene Responsible for Cystinosis, Ctns

BACKGROUND: Cystinosis is an autosomal recessive disorder characterised by an intralysosomal accumulation of cystine, and affected individuals progress to end-stage renal failure before the age of ten. The causative gene, CTNS, was cloned in 1998 and the encoded protein, cystinosin, was predicted to be a lysosomal membrane protein. RESULTS: We have cloned the murine homologue of CTNS, Ctns, and the encoded amino acid sequence is 92.6% similar to cystinosin. We localised Ctns to mouse chromosome 11 in a region syntenic to human chromosome 17 containing CTNS. Ctns is widely expressed in all tissues tested with the exception of skeletal muscle, in contrast to CTNS. CONCLUSIONS: We have isolated, characterised and localised Ctns, the murine homologue of CTNS underlying cystinosis. Furthermore, our work has brought to light the existence of a differential pattern of expression between the human and murine homologues, providing critical information for the generation of a mouse model for cystinosis

HLA-G gene editing: a novel therapeutic alternative in cancer immunotherapy

Cancer immunotherapies based mainly on the blockade of immune-checkpoint (IC) molecules by anti-IC antibodies offer new alternatives for treatment in oncological diseases. However, a considerable proportion of patients remain unresponsive to them. Hence, the development of novel clinical immunotherapeutic approaches and/or targets are crucial. In this context, targeting the immune-checkpoint HLA-G/ILT2/ILT4 has caused great interest since it is abnormally expressed in several malignancies generating a tolerogenic microenvironment. Here, we used CRISPR/Cas9 gene editing to block the HLA-G expression in two tumor cell lines expressing HLA-G, including a renal cell carcinoma (RCC7) and a choriocarcinoma (JEG-3). Different sgRNA/Cas9 plasmids targeting HLA-G exon 1 and 2 were transfected in both cell lines. Downregulation of HLAG was reached to different degrees, including complete silencing. Most importantly, HLA-G – cells triggered a higher in vitro response of immune cells with respect to HLA-G + wild type cells. Altogether, we demonstrated for the first time the HLA-G downregulation through gene editing. We propose this approach as a first step to develop novel clinical immunotherapeutic approaches in cancer.Fil: Palma, María Belén. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Cátedra de Citología, Histología y Embriología; Argentina. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina.Fil: Tronik-Le Roux, Diana. Saint-Louis Hospital; Francia. Université de Paris; Francia.Fil: Amín, Guadalupe. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina.Fil: Castañeda, Sheila. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina.Fil: Möbbs, Alan M. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina.Fil: Scarafia, María Agustina. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina.Fil: La Greca, Alejandro. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina.Fil: Daouya, Marina. Saint-Louis Hospital; Francia. Université de Paris; Francia.Fil: Poras, Isabelle. Saint-Louis Hospital; Francia. Université de Paris; Francia.Fil: Inda, Ana María. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Cátedra de Citología, Histología y Embriología; Argentina. Comisión de Investigaciones Científicas; Argentina.Fil: Moro, Lucía Natalia. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Carosella, Edgardo D. Saint-Louis Hospital; Francia. Université de Paris; Francia.Fil: García, Marcela N. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Cátedra de Citología, Histología y Embriología; Argentina.Fil: Miriuka, Santiago G. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Cátedra de Citología, Histología y Embriología; Argentina. Fleni. Laboratorio de Investigación Aplicada a las Neurociencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

HLA-G gene editing in tumor cell lines as a novel alternative in cancer immunotherapy

Cancer immunotherapies based mainly on the blockade of immune-checkpoint (IC) molecules by anti-IC antibodies offer new alternatives for treatment in oncological diseases. However, a considerable proportion of patients remain unresponsive to them. Hence, the development of novel clinical immunotherapeutic approaches and/or targets are crucial.W In this context, targeting the immune-checkpoint HLA-G/ILT2/ILT4 has caused great interest since it is abnormally expressed in several malignancies generating a tolerogenic microenvironment. Here, we used CRISPR/Cas9 gene editing to block the HLA-G expression in two tumor cell lines expressing HLA-G, including a renal cell carcinoma (RCC7) and a choriocarcinoma (JEG-3). Different sgRNA/Cas9 plasmids targeting HLA-G exon 1 and 2 were transfected in both cell lines. Downregulation of HLA-G was reached to different degrees, including complete silencing. Most importantly, HLA-G − cells triggered a higher in vitro response of immune cells with respect to HLA-G + wild type cells. Altogether, we demonstrated for the first time the HLA-G downregulation through gene editing. We propose this approach as a first step to develop novel clinical immunotherapeutic approaches in cancer.Fil: Palma, Maria Belen. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Ciencias Morfológicas. Cátedra de Citología y Embriología A; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Tronik Le Roux, Diana. Saint-Louis Hospital; Francia. Universite de Paris 1 - Pantheon Sorbonne.; FranciaFil: Amin, Guadalupe. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Castañeda, Sheila Lucia. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Möbbs, Alan Miqueas. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scarafia, Maria Agustina. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: la Greca, Alejandro Damián. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Daouya, Marina. Hôpital Saint-louis; Francia. Universite de Paris 1 - Pantheon Sorbonne.; FranciaFil: Poras, Isabelle. Hôpital Saint-louis; Francia. Universite de Paris 1 - Pantheon Sorbonne.; FranciaFil: Inda, Ana María. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Ciencias Morfológicas. Cátedra de Citología y Embriología A; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Moro, Lucía Natalia. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carosella, Edgardo Delfino. Hôpital Saint-louis; Francia. Universite de Paris 1 - Pantheon Sorbonne.; FranciaFil: García, Marcela Nilda. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Departamento de Ciencias Morfológicas. Cátedra de Citología y Embriología A; ArgentinaFil: Miriuka, Santiago Gabriel. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

RREB-1 Is a Transcriptional Repressor of HLA-G

Abstract The nonclassical HLA-G is a molecule specifically involved in immune tolerance with highly restricted tissue distribution in healthy conditions. Yet it is overexpressed in numerous tumors and in allografts with better acceptance. Major mechanisms involved in regulation of HLA-G transcription are still poorly described. Thus, to characterize these mechanisms we have developed a specific proteomic approach to identify proteins that bind differentially to the HLA-G gene promoter by promoter pull-down assay followed by spectrometry mass analysis. Among specific binding factors, we focused on RREB-1, a ras-responsive element binding protein 1. We demonstrated that RREB-1 represses HLA-G transcriptional activity and binds three ras response elements within the HLA-G promoter. RREB-1 protein, specifically in HLA-G-negative cells, interacts with subunits of CtBP complex implicated in chromatin remodeling. This demonstration is the first of a repressor factor of HLA-G transcriptional activity taking part in HLA-G repression by epigenetic mechanisms.</jats:p

Hypoxia inducible factor-1 mediates the expression of the immune checkpoint HLA-G in glioma cells through hypoxia response element located in exon 2

International audienceHLA-G is an immune checkpoint molecule with specific relevance in cancer immunotherapy. It was first identified in cytotrophoblasts, protecting the fetus from maternal rejection. HLA-G tissue expression is very restricted but induced in numerous malignant tumors such as glioblastoma, contributing to their immune escape. Hypoxia occurs during placenta and tumor development and was shown to activate HLA-G. We aimed to elucidate the mechanisms of HLA-G activation under conditions combining hypoxia-mimicking treatment and 5-aza-2’deoxycytidine, a DNA demethylating agent used in anti-cancer therapy which also induces HLA-G. Both treatments enhanced the amount of HLA-G mRNA and protein in HLA-G negative U251MG glioma cells. Electrophoretic Mobility Shift Assays and luciferase reporter gene assays revealed that HLA-G upregulation depends on Hypoxia Inducible Factor-1 (HIF-1) and a hypoxia responsive element (HRE) located in exon 2. A polymorphic HRE at –966 bp in the 5’UT region may modulate the magnitude of the response mediated by the exon 2 HRE. We suggest that therapeutic strategies should take into account that HLA-G expression in response to hypoxic tumor environment is dependent on HLA-G gene polymorphism and DNA methylation state at the HLA-G locus

Are the Immune Properties of Mesenchymal Stem Cells from Wharton’s Jelly Maintained during Chondrogenic Differentiation?

International audienceBackground: Umbilical mesenchymal stem/stromal cells (MSCs), and especially those derived from Wharton’s jelly (WJ), are a promising engineering tool for tissue repair in an allogeneic context. This is due to their differentiation capacity and immunological properties, like their immunomodulatory potential and paracrine activity. Hence, these cells may be considered an Advanced Therapy Medicinal Product (ATMP). The purpose of this work was to differentiate MSCs from WJ (WJ-MSCs) into chondrocytes using a scaffold and to evaluate, in vitro, the immunomodulatory capacities of WJ-MSCs in an allogeneic and inflammatory context, mimicked by IFN-γ and TNF-α priming during the chondrogenic differentiation. Methods: Scaffolds were made from hydrogel composed by alginate enriched in hyaluronic acid (Alg/HA). Chondrogenic differentiation, immunological function, phenotype expression, but also secreted soluble factors were the different parameters followed during 28 days of culture. Results: During chondrocyte differentiation, even in an allogeneic context, WJ-MSCs remained unable to establish the immunological synapse or to induce T cell alloproliferation. Moreover, interestingly, paracrine activity and functional immunomodulation were maintained during cell differentiation. Conclusion: These results show that WJ-MSCs remained hypoimmunogenic and retained immunomodulatory properties even when they had undergone chondrocyte differentiation