Immune thrombocytopenia (ITP) is a hemorrhagic autoimmune disease characterized by antibody-mediated platelet injury. ITP has complicated immunopathological mechanisms that need further elucidation. It is well known that the costimulatory molecules OX40 ligand (OX40L) and OX40 play essential roles in the immunological mechanisms of autoimmune diseases. Previously, we discovered that the expression of OX40L and OX40 is significantly increased in the peripheral blood mononuclear cells (PBMCs) of ITP patients. In our present study, OX40L-induced follicular helper T (Tfh) cells exhibited an activated phenotype with elevated expression of inducible T-cell costimulator (ICOS), programmed cell death protein-1 (PD-1), and cluster of differentiation 40 ligand (CD40L) in vitro. Moreover, aberrant OX40L‒OX40 expression might promote the Tfh1-to-Tfh2 shift in vivo, inducing the generation of autoantibodies by enhancing the helper function of Tfh cells for B lymphocytes in a mouse model, which might accelerate the progression of ITP. Additionally, signal transduction through the OX40L‒OX40 axis might be related to the activation of tumor necrosis factor receptor-associated factor (TRAF)‒nuclear factor-κB (NF-κB) and Janus kinase (JAK)‒signal transducer and activator of transcription (STAT) signaling pathways. Overall, OX40L‒OX40 signaling is proposed as a potential novel therapeutic target for ITP.
Animals ; OX40 Ligand/physiology* ; Purpura, Thrombocytopenic, Idiopathic/immunology* ; Cell Differentiation ; Mice ; T-Lymphocytes, Helper-Inducer/cytology* ; T Follicular Helper Cells/cytology* ; Signal Transduction ; Receptors, OX40 ; Mice, Inbred C57BL ; Humans ; Female

Objective To explore the significance of interleukin-17C(IL-17C)-mediated follicular helper T cell (Tfh) differentiation in atopic dermatitis (AD) model. Methods BALB/c mice were divided into control group, AD model group, low-dose MOR106 (anti-IL-17C huIgG1)(MDR106-L)treatment group and high-dose MOR106 (MOR106-H) treatment group, 8 mice in each group. Except for the control group, all the other groups were treated with 2, 4- dinitrochlorobenzene (DNCB) to establish AD models. The low-dose and high-dose MOR106 groups were treated with 5 mg/kg or 10 mg/kg MOR106 respectively. The differentiation of Tfh cell subsets in peripheral blood of mice was analyzed by flow cytometry, and the expression of Janus kinase 2/signal transducer and activator of transcription 3(JAK2/STAT3) signal pathway protein in skin tissue was detected by Western blot analysis. Results Compared with the control group, the dermatitis severity score, mass difference between two ears, spleen mass and spleen index of DNCB group increased significantly, while those of MOR106-L group and MOR106-H group decreased significantly. Compared with the control group, the Tfh subgroup of AD mice showed deregulated differentiation, resulting in a significant increase in the percentage of CD4⁺CXCR5⁺IFN-γ⁺Tfh1 cells, CD4⁺CXCR5⁺IL-17A⁺Tfh17 and CD4⁺CXCR5⁺IL-21⁺Tfh21 cells, and a significant decrease in the percentage of CD4⁺CXCR5⁺IL-10⁺Tfh10 cells and CD4⁺CXCR5⁺FOXP3⁺Tfr cells in peripheral blood. The protein levels of phosphorylated JAK2(p-JAK2) and p-STAT3 were significantly increased. MOR106 effectively reversed these changes of Tfh1, Tfh10, Tfh17, Tfh21 and Tfr cells in peripheral blood of AD mice. Compared with AD group, the levels of p-JAK2 and p-STAT3 protein in low-dose and high-dose MOR106 treatment groups decreased significantly. Conclusion MOR106 can reduce the inflammatory response of AD mice by blocking JAK2/STAT3 signaling pathway and inhibiting the differentiation of Tfh cells mediated by IL-17C.
Animals ; Mice ; Dermatitis, Atopic/drug therapy* ; Interleukin-17 ; T Follicular Helper Cells ; Janus Kinase 2 ; Dinitrochlorobenzene ; Inflammation ; Cell Differentiation ; Signal Transduction

B-Lymphocytes ; Graft vs Host Disease ; Humans ; Immunoglobulin D ; T Follicular Helper Cells ; T-Lymphocytes, Helper-Inducer

OBJECTIVE: To explore the role of follicular helper T cell (Tfh)/ follicular regulatory T cell (Tfr) imbalance in B-cell lymphoma (BCL). METHODS: Sixteen BCL patients who were admitted to the Department of Hematology of The First People's Hospital of Yichang and 20 healthy people from December 2019 to November 2020 were enrolled and respectively divided into observation group and control group. The levels of Tfh and Tfr in peripheral blood were detected by flow cytometry. The changes of Tfh, Tfr, and Tfh/Tfr ratio were compared and the relationship between Tfh/Tfr ratio and efficacy, prognosis was analyzed. RESULTS: Compared with the healthy controls, Tfh and Tfh/Tfr ratio in peripheral blood of the BCL patients increased (P<0.05, P<0.01), while levels of Tfr was decreased (P<0.01). After chemotherapy, Tfh and Tfh/Tfr ratio in peripheral blood of the BCL patients decreased significantly than before chemotherapy (P<0.01), but Tfr was no significant difference. Multivariate analysis showed that Tfh and Tfh/Tfr ratio were positively correlated with international prognostic index (IPI) score and Ann Arbor stage (r=0.626, 0.564, 0.573, 0.608, respectively), while Tfr negatively (r=－0.504, －0.542, respectively). According to the average value of Tfh/Tfr ratio at initial diagnosis, BCL patients were divided into Tfh/Tfr high ratio group and low ratio group. It was found that the complete remission (CR) rate, overall response rate (ORR), and survival time in the high ratio group were significantly lower than the low ratio group (P<0.01). CONCLUSION There is an imbalance of Tfh/Tfr ratio in peripheral blood of the BCL patients, and those with a high Tfh/Tfr ratio have lower CR, ORR and shorter survival time.
Flow Cytometry ; Humans ; Lymphoma, B-Cell ; T Follicular Helper Cells ; T-Lymphocytes, Helper-Inducer ; T-Lymphocytes, Regulatory