Suchergebnisse

Graft versus host disease (GvHD) is the main complication of allogeneic hematopoietic stem cell transplantation (HSCT). Here we report studies of a patient with chronic GvHD (cGvHD) carrying persistent CD4 T cell clonal expansion harboring somatic mTOR, NFKB2, and TLR2 mutations. In the screening cohort (n = 134), we detect the mTOR P2229R kinase domain mutation in two additional cGvHD patients, but not in healthy or HSCT patients without cGvHD. Functional analyses of the mTOR mutation indicate a gain-of-function alteration and activation of both mTORC1 and mTORC2 signaling pathways, leading to increased cell proliferation and decreased apoptosis. Single-cell RNA sequencing and real-time impedance measurements support increased cytotoxicity of mutated CD4 T cells. High throughput drug-sensitivity testing suggests that mutations induce resistance to mTOR inhibitors, but increase sensitivity for HSP90 inhibitors. Our findings imply that somatic mutations may contribute to aberrant T cell proliferations and persistent immune activation in cGvHD, thereby paving the way for targeted therapies. + + ; This work was supported by the European Research Council (M-IMM project), Academy of Finland (Decisions 287224, 314442), Finnish special governmental subsidy for health sciences, research and training, Sigrid Juselius Foundation, Instrumentarium Science foundation, Helsinki Institute of Life Sciences Fellow funding, Cancer Foundation Finland, and Finnish Cancer Institute. T.L. was supported by the Academy of Finland (Decisions 311081 and 314557). This study was supported by Finnish Functional Genomics Center, University of Turku, Åbo Akademi University and Biocenter Finland. IT Center for Science LTD (CSC) is acknowledged for their help and computing resources.

T-cell prolymphocytic leukemia (T-PLL) is a poor prognostic disease with very limited options of efficient therapies. Most patients are refractory to chemotherapies and despite high response rates after alemtuzumab, virtually all patients relapse. Therefore, there is an unmet medical need for novel therapies in T-PLL. As the chemokine receptor CCR7 is a molecule expressed in a wide range of malignancies and relevant in many tumor processes, the present study addressed the biologic role of this receptor in T-PLL. Furthermore, we elucidated the mechanisms of action mediated by an anti-CCR7 monoclonal antibody (mAb) and evaluated whether its anti-tumor activity would warrant development towards clinical applications in T-PLL. Our results demonstrate that CCR7 is a prognostic biomarker for overall survival in T-PLL patients and a functional receptor involved in the migration, invasion, and survival of leukemic cells. Targeting CCR7 with a mAb inhibited ligand-mediated signaling pathways and induced tumor cell killing in primary samples. In addition, directing antibodies against CCR7 was highly effective in T-cell leukemia xenograft models. Together, these findings make CCR7 an attractive molecule for novel mAb-based therapeutic applications in T-PLL, a disease where recent drug screen efforts and studies addressing new compounds have focused on chemotherapy or small molecules. ; Funding for this work was by grant PI015/02085 and PI18/01163 from the Fondo de Investigaciones Sanitarias, Ministerio de Sanidad y Consumo, Spain to CMC who was also cofinanced by FEDER funds. CCM and FT were supported by RTC-2015-3318-1 (Ministerio de Economía y Competitividad, Spain). MH was funded by the German Research Foundation (DFG; HE3553/ 4–2) as part of the collaborative research group on mature T-cell lymphomas, "CONTROL-T" (FOR1961). The José Carreras Leukemia Foundation (03F/2016), the Köln Fortune Program, and the Fritz Thyssen foundation (10.15.2.034MN) supported MH and AS. The Köln Fortune Program also supported LW. SM was supported by the Finnish Cancer Organizations, the Finnish Cancer Institute, Academy of Finland and the Sigrid Juselius Foundation. SM and MH are supported by the ERAPerMed program 'JAK- STAT-TARGET'. MLT was granted by SAF2016–75442-R (Agencia Estatal de Investigación/ European Regional Development Fund, European Union, Spain).