Project description:Background: Angioimmunoblastic T-cell lymphoma (AITL) is a malignancy with very poor survival outcome, in need of new more specific therapeutic regimen. The drivers of malignancy in this disease are CD4+ follicular helper T cells (Tfh). The metabolism of these malignant Tfh cells was not yet elucidated. Therefore, we decided to identify their metabolic requirements with the objective to propose a novel therapeutic option. Methods: To reveal the prominent metabolic pathways used by the AITL lymphoma cells, leveraged on our previously established AITL mouse model by crossing metabolomic and proteomic data of murine AITL cells. We confirmed these results using AITL patient and healthy T cell expression data. Results: Strikingly, the mAITL Tfh cells were highly dependent on the second branch of the Kennedy pathway, the choline lipid pathway, responsible for the production of the major membrane constituent phosphatidylcholine. Moreover, gene expression data from Tfh cells isolated from AITL patient tumors, confirmed the upregulation of the choline lipid pathway. Several enzymes involved in this pathway such as choline kinase, catalyzing the first step in the phosphatidylcholine pathway, respectively, are upregulated in multiple tumors other than AITL. Here we showed that treatment of our mAITL preclinical mouse model with the fatty acid oxydation inhibitor, etomoxir, significantly increased their survival and even reverted the exhausted CD8 T cells in the tumor into potent cytotoxic anti-tumor cells. Specific inhibition of Chok confirmed the importance of the phosphatidylcholine production pathway in the neoplastic CD4+ T cells, since it irradicated almost all the mAITL Tfh cells from the tumors. Finally, the same inhibitor induced in human AITL lymphoma biopsies cell death of the majority of the hAITL PD-1high neoplastic cells. Conclusion: Our results suggest that interfering with the choline metabolism in AITL might represent a new therapeutic strategy for these patients.
Project description:Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma that originates from T follicular helper (Tfh) cells and is characterized by a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL but their contribution to tumorigenesis is poorly understood. We have developed an AITL mouse model that is driven by Idh2 and Tet2 mutations and in which Tfh cells exhibit aberrant transcriptomic and epigenetic programming. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered crosstalk with normal germinal center B cells that promotes B clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. This altered Tfh-B cell communication could explain the unique relationship between Idh2 mutation and the prototypical AITL TME. Our mouse model also recapitulates important features of human IDH2-mutated AITL, providing a rationale for exploring the therapeutic targeting of Tfh-TME crosstalk for AITL treatment.
Project description:Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma that originates from T follicular helper (Tfh) cells and is characterized by a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL but their contribution to tumorigenesis is poorly understood. We have developed an AITL mouse model that is driven by Idh2 and Tet2 mutations and in which Tfh cells exhibit aberrant transcriptomic and epigenetic programming. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered crosstalk with normal germinal center B cells that promotes B clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. This altered Tfh-B cell communication could explain the unique relationship between Idh2 mutation and the prototypical AITL TME. Our mouse model also recapitulates important features of human IDH2-mutated AITL, providing a rationale for exploring the therapeutic targeting of Tfh-TME crosstalk for AITL treatment.
Project description:Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma that originates from T follicular helper (Tfh) cells and is characterized by a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL but their contribution to tumorigenesis is poorly understood. We have developed an AITL mouse model that is driven by Idh2 and Tet2 mutations and in which Tfh cells exhibit aberrant transcriptomic and epigenetic programming. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered crosstalk with normal germinal center B cells that promotes B clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. This altered Tfh-B cell communication could explain the unique relationship between Idh2 mutation and the prototypical AITL TME. Our mouse model also recapitulates important features of human IDH2-mutated AITL, providing a rationale for exploring the therapeutic targeting of Tfh-TME crosstalk for AITL treatment.
Project description:Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma that originates from T follicular helper (Tfh) cells and is characterized by a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL but their contribution to tumorigenesis is poorly understood. We have developed an AITL mouse model that is driven by Idh2 and Tet2 mutations and in which Tfh cells exhibit aberrant transcriptomic and epigenetic programming. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered crosstalk with normal germinal center B cells that promotes B clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. This altered Tfh-B cell communication could explain the unique relationship between Idh2 mutation and the prototypical AITL TME. Our mouse model also recapitulates important features of human IDH2-mutated AITL, providing a rationale for exploring the therapeutic targeting of Tfh-TME crosstalk for AITL treatment.
Project description:Human peripheral monocytes have been categorized into three subsets based on differential expression levels of CD14 and CD16. However, the factors that influence the distribution of monocyte subsets and the roles which each subset plays in autoimmunity are not well studied. To compare the gene expression profiling 1) on intermediate monocytes CD14++CD16+ monocytes between healthy donors and autoimmune uveitis patients and 2) among 3 monocyte subsets in health donors, here we purified circulating intermediate CD14++CD16+ monocytes from 5 patients with autoimmune uveitis (labeled as P1-5) and 4 healthy donors (labeled as HD1-4) by flow cytometry and isolated total RNA to proceed microarray assay. In addition, we also purified CD14+CD16++ (non-classical monocytes) and CD14++CD16- (classical monocytes) from 4 healthy donors to do microarray. We demonstrate that CD14++CD16+ monocytes from patients and healthy control donors share a similar gene expression profile. The CD14+CD16++ cells (non-classical monocytes) display the most distinctive gene expression profiling when compared to intermediate CD14++CD16+ monocytes and classical CD14++CD16- monocytes.
Project description:Microarray analysis of bone marrow multipotent mesenchymal stromal cells isolated from type 1 diabetes patients and healthy donors.