HLA-G*0105N null allele encodes functional HLA-G isoforms.

Expression of the nonclassical HLA class I antigen, HLA-G, is associated with immune tolerance in view of its role in maintaining the fetus in utero, allowing tumor escape, and favoring graft acceptance. Expressed on invasive trophoblast cells, HLA-G molecules bind inhibitory receptors on maternal T lymphocytes and NK cells, thereby blocking their cytolytic activities and protecting the fetus from maternal immune system attack. The HLA-G gene consists of 15 alleles, including a null allele, HLA-G*0105N. HLA-G*0105N presents a single base deletion, preventing translation of both membrane-bound (HLA-G1) and full-length soluble isoforms (HLA-G5) as well as of the spliced HLA-G4 isoform. The identification of healthy subjects homozygous for this HLA-G null allele suggests that the HLA-G*0105N allele may generate other HLA-G isoforms, such as membrane-bound HLA-G2 and -G3 and the soluble HLA-G6 and -G7 proteins, which may substitute for HLA-G1 and -G5, thus assuming the immune tolerogeneic function of HLA-G. To investigate this point, we cloned genomic HLA-G*0105N DNA and transfected it into an HLA-class I-positive human cell line. The results obtained indicated that HLA-G proteins were indeed present in HLA-G*0105N-transfected cells and were able to protect against NK cell lysis. These findings emphasize the role of the other HLA-G isoforms as immune tolerogeneic molecules that may also contribute to maternal tolerance of the semiallogenic fetus as well as tumor escape and other types of allogeneic tissue acceptance

Methods for Establishing a Renal Cell Carcinoma Tumor Spheroid Model With Immune Infiltration for Immunotherapeutic Studies

Tumor spheroids play an increasingly important role in cancer research. Their ability to recapitulate crucial features of tumor biology that are lost in the classically used 2D models along with their relative simplicity and handiness have made them the most studied 3D tumor model. Their application as a theranostic tool or as a means to study tumor-host interaction is now well-established in various cancers. However, their use in the field of Renal Cell Carcinoma (RCC) remains very limited. The aim of this work is to present methods to implement a basic RCC spheroid model. These methods cover the steps from RCC tumor dissociation to spheroid infiltration by immune cells. We present a protocol for RCC dissociation using Liberase TM and introduce a culture medium containing Epithelial Growth Factor and Hydrocortisone allowing for faster growth of RCC primary cells. We show that the liquid overlay technique allows for the formation of spheroids from cell lines and from primary cultures. We present a method using morphological criteria to select a homogeneous spheroid population based on a Fiji macro. We then show that spheroids can be infiltrated by PBMCs after activation with OKT3 or IL-15. Finally, we provide an example of application by implementing an immune spheroid killing assay allowing observing increased spheroid destruction after treatment with PD-1 inhibitors. Thus the straightforward methods presented here allow for efficient spheroid formation for a simple RCC 3D model that can be standardized and infused with immune cells to study immunotherapies

Régulation de la fonction lymphocytaire T en rejet d'allogreffe (implications des molécules HLA - G et PKC bêta)

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Démonstration in vivo du rôle de la molécule HLA-G dans l'échappement des tumeurs solides au système immunitaire

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Fonctions immunologiques de la molécule HLA-G (implications en Transplantation et Cancérologie)

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Expression et fonction des molécules HLA-G dans des cellules normales trophoblastiques et érythropoïétiques et dans des cellules tumorales de mélanome

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Démonstration du rôle tolérogène de la molécule HLA-G en transplantation

Face aux thérapeutiques actuelles confrontées au risque de rejet de greffe, nos recherches ont porté sur la compréhension des mécanismes par lesquels la molécule HLA de classe I, non classique, HLA-G induit un état de tolérance entre donneur et receveur. Après double transplantation foie-rein, l'expression de HLA-G par les greffons est associée à une meilleure acceptation de la double greffe. Nous montrons que HLA-G est également retrouvée au niveau des cellules immunocompétentes (lymphocytes T CD4+ et CD8+) du receveur circulant en périphérie. Par ailleurs, la présence d'une forme soluble de HLA-G, à un taux très élevé dans le sérum de ces patients, a pu être directement associée à un mécanisme actif de tolérance, conduisant au non-rejet de greffes tissulairesPARIS5-BU-Necker : Fermée (751152101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF