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Clemenceau, B.

Publications and source records attributed to Clemenceau, B..

3 recordsLinked to original sources

Functional diversity of Vγ9Vδ2 T cells overcomes glioblastoma state plasticity and antigen heterogeneity

Glioblastoma (GBM) is characterized by a high degree of cellular plasticity and intra-tumoral heterogeneity, which frequently leads to the failure of standard therapies, including immunotherapies. While chimeric antigen receptor (CAR) T cells offer a potent means of MHC-independent tumor recognition, their efficacy is hampered by the coexistence of distinct molecular states, gathered as proneural (PN) and mesenchymal (MES) phenotypes. Here, we demonstrate that gangliosides GD2 and O-acetylated GD2 (OAcGD2) are preferentially expressed by PN cells whereas MES cells display reduced expression due to upregulated ganglioside catabolism. Conversely, MES cells are known to exhibit high expression of stress-induced ligands recognized by V{gamma}9V{delta}2 T cells. We show that while engineering V{delta}2T cells with GD2- or OAcGD2-specific CAR enables the elimination of PN cells, it also facilitates the immune escape of MES cells in heterogeneous 3D-tumoroid models. Mechanistically, we reveal a hierarchy of receptor engagement, where CAR signaling predominates leading to the structural and functional exclusion of endogenous TCR from the immunological synapse. To address this receptor competition, we propose a strategy that leverages the functional effector diversity by combining untransduced and CAR-engineered V{delta}2T cells. This dual approach provides a dynamic safety net by ensuring the simultaneous elimination of PN and MES cells and preventing the selective outgrowth of resistant cells. Our findings establish a conceptual framework for designing off-the-shelf immunotherapies tailored to the metabolic and phenotypic plasticity of resistant solid tumors.

cancer biology↗

Clonal analysis of SepSecS-specific CD4 T cells reveals a new HLA-DPA1*02:01/HLA-DPB1*01:01-restricted immunodominant epitope in autoimmune hepatitis

Autoreactive CD4 T cells, recognizing liver-self-antigens such as SepSecS, are main drivers of the chronic inflammatory response during autoimmune hepatitis (AIH). Previous studies have uncovered immunodominant SepSecS epitopes often associated with HLA-DRB1*03 or HLA-DRB1*04 restriction, two alleles enriched in AIH population. However, HLA restriction of numerous SepSecS epitopes remains incomplete and it is still unclear if immunodominant epitopes could be presented by non-HLA-DR molecules. Here, we investigated epitope recognition of SepSecS-specific TCRs isolated from AIH patients, and their HLA restriction by generating TCR hybridoma cell lines. Seventeen TCRs recognized eight SepSecS epitopes with four distinct HLA restrictions, including a novel HLA-DPA1*02:01/DPB1*01:01-restricted SepSecS epitope. TCR clustering analysis using GLIPH2 algorithm suggested that this epitope is recognized by multiple distinct TCRs in HLA-DPA1*02:01[~]HLA-DPB1*01:01 patients. Our study provides new insights into liver-self-antigen T cell reactivity during AIH, which could offer potential therapeutic strategies by targeting autoreactive CD4 T cells.

immunology↗

Targeting pediatric High-Grade Gliomas with OAcGD2-CAR Vδ2 T cells

PurposePediatric high-grade gliomas (pHGG) belong to a family of rare childrens cancers which are treated with radiotherapy, based on adult high-grade glioma standard of care. However, new treatments are definitively required since actual ones are unable to extend survival by more than a few months in most patients. In this study, we investigate a Chimeric Antigen Receptor (CAR)-T cell immunotherapy targeting the OAcGD2 ganglioside, using either conventional {beta} or V{delta}2 T cells as effectors. Materials and methodsUsing relevant human primary models of pHGG, we first characterized the innate V{delta}2 T cell immunoreactivity. Then, following the validation of OAcGD2 expression in these tumor cells, we evaluated both {beta} and V{delta}2 OAcGD2-CAR-T cell immunoreactivity using various methods including videomicroscopy, FACS and cytotoxicity assays. ResultsWe showed that pHGG primary cells are not spontaneously recognized and killed by V{delta}2 T cells but significantly expressed the OAcGD2 ganglioside. Accordingly, both {beta} and V{delta}2 T cells engineered to express a CAR against the OAcGD2 efficiently killed pHGG cells in 2D and 3D models. Importantly, only V{delta}2 T cells transduced with the complete OAcGD2-CAR eliminated pHGG cells, in contrast to conventional {beta} CAR-T cells that killed tumor cells even in the absence of CAR expression, highlighting the allogeneic potential of V{delta}2 CAR-T cells. ConclusionOur study demonstrates the preclinical relevance of targeting OAcGD2 in pHGG using CAR-T cells. Furthermore, we also clearly demonstrate the clinical benefits of using V{delta}2 T cells as CAR effectors in allogeneic settings allowing an off-the-shelf immunotherapy.

cancer biology↗