Effect Of JAK2v617f Gene Mutation On Dendritic Cells And Its Role In JAK2v617f(+)MPN

BackgroundClassical Ph-MPN is mainly divided into polycythemia vera(PV),essential thrombocythemia(ET),and primary myelofibrosis(MF).Although MPN is mainly driven by JAK2v617f,CALR and MPL mutation genes,some patients can progress from PV/ET to MF with the increase of driver gene load,clonal evolution,increase of myelofibrosis,chronic inflammation and epigenetic regulation,but the specific mechanism is still unclear,and the targeted therapy is relatively lack.With the progress of research,the impact of tumor immunity and tumor microenvironment on the progression of hematological tumors has been gradually realized.In the tumor microenvironment,the deficiency of immune surveillance mainly by dendritic cells(DCs)and the weakening of immune killing mainly by T cells are important reasons leading to the continuous development of tumors.The application of CD47 monoclonal antibody and PD-1/PD-L1 can effectively eliminate the immune rheostat("immunostat")phenomenon in the microenvironment,and the effect is obvious in the treatment of myeloid leukemia and lymphoma,especially in relapsed/refractory patients.Therefore,it is particularly important to clarify the tumor immune characteristics of MPN and to implement targeted therapy for the key nodes of MPN immune deficiency to delay or reverse the progression of MPN.Purpose1.To characterize the immunophenotypes of the tumor microenvironment of JAK2v617f(+)MPN by examining the functional status of DCs and T cells in bone marrow and peripheral blood of JAK2v617f(+)MPN in the disease background.2.To explore the relationship between abnormal tumor immunity and disease progression in MPN using mouse models.3.Optimize the existing treatment strategies according to the research results,explore new targets for MPN tumor immunotherapy,solve the clinical problems of treatment intolerance and/or drug resistance in some patients,and provide basis and direction for reducing or erasing the tumor burden and delaying or reversing the disease process.MethodI.The number of DCs and T cells in bone marrow and peripheral blood was measured by Flow cytometry.2.The expression levels of CD83,CD80,CD86,HLA-DR and HLA-ABC on DCs were detected to reflect the maturation and function of DCs.The antigen presentation ability of DCs was detected by the activation and proliferation of T cells after co-culture with T cells.3.In vivo experiments in CD11cDTR mice confirmed that DCs depletion could directly reduce the number of T cells,weaken the proliferation ability and Th1 and Tc1 polarization.4.The differential genes between JAK2v617f(+)MPN DCs and normal DCs were identified by RNA-seq sequencing,and the phenotype was further verified and rescued.5.Excavate and verify new targets of clinical immunotherapy according to experimental results.Results1.The number of CD3+T cells,CD4+T cells,CD8+T cells in bone marrow and peripheral blood of JAK2v617f(+)MPN patients was decreased,and the proliferation ability of T cells was weakened.However,the expression of CD57,PD-1 and Tim3 on CD4+T cells and CD8+T cells,the apoptosis of T cells,the level of IL-2 secretion and the subsets of T cells did not change significantly.2.The proportion and number of DCs in bone marrow and peripheral blood of J4K2v617f(+)MPN patients were decreased,the maturation(activation)of DCS was decreased,the expression of HLA molecules and co-stimulatory molecules was weakened,the ability of antigen presentation was weakened,and the ability of migration was weakened.Transcriptome analysis showed that the differences between JAK2v617f(+)MPN DCs and normal DCs mainly focused on viral infection,antigen processing,antigen presentation and immune response initiation.3.The reduction of DCs can directly reduce the number of T cells,weaken the proliferation ability and Thl and Tcl polarization.4.The differentiation ratio of monocytes and DCs was biased during hematopoiesis in JAK2v617f(+)MPN,resulting in the reduction of DCs number.5.JAK2-STAT3 signaling pathway is involved in mediating the weakened function of DCs.IFNa2b and STAT-3 inhibitors can restore the functional defects of DCs.ConclusionJAK2v617f mutation activates JAK2-STAT3 signaling pathway in DCs,affects the function of DCs,leads to the reduction of immune surveillance level of MPN,and weakens the anti-tumor immunity of T cells in MPN.IFNa2b and/or STAT3 inhibitors can effectively restore the function of DCs,reverse the anti-tumor immune deficiency of MPN,and delay or reverse the progression of MPN.BackgroundPrimary immune thrombocytopenia(ITP)is an acquired autoimmune disease characterized by increased platelet destruction and/or decreased platelet production.About 40-60%of newly diagnosed ITP patients achieve remission for more than 6 months or even more than 1 year after first-line treatment,but most patients will experience a chronic or relapsing/remitting course.There are few clinical studies on the drug selection and efficacy evaluation of relapse treatment in patients with chronic ITP or persistent ITP.ObjectiveTo evaluate the efficacy and safety of intravenous immunoglobulin(IVIg)combined with corticosteroids versus monotherapy in the treatment of relapsed ITP in adults.MethodsClinical data of 205 adult patients with relapsed ITP treated with first-line combination therapy or monotherapy from multiple centers in China from January 2010 to December 2022 were retrospectively analyzed.The clinical characteristics,efficacy and safety of the patients were evaluated.ResultsThe proportion of patients with platelet count in CR(71.83%)was significantly higher than that in IVIg group(43.48%)and corticosteroids group(23.08%).The mean maximum of platelet count in combination group(178×109/L)was significantly higher than that in IVIg group(109×109/L)and corticosteroids group(76×109/L).The average days of platelet counts reaching 30×109/L,50×109/L and 100×109/L in the combination group were 2 days,3 days and 4 days,which were significantly shorter than those in the single drug groups.The proportion curves reaching 30×109/L,50×109/L,and 100×109/L per day during treatment were also significantly different from those in the single drug groups.There were no significant differences in the effective rate,clinical characteristics and adverse events among the three groups.ConclusionThe onset time and efficacy of IVIg combined with corticosteroids in the treatment of relapsed ITP in adults were significantly better than those of first-line drug monotherapy groups,which provides clinical evidence and reference for the clinical application of first-line drug combination in the treatment of relapsed ITP in adults.