Changes And Significance Of Follicular Helper T Cells And Follicular Regulatory T Cells In Invasive Fungal Disease

Objective:Follicular helper T cells（Tfh）and follicular regulatory T cells（Tfr）are newly discovered subtypes of helper T（CD4⁺T）cells in recent years,which play an important role in the formation of germinal centers,the proliferation and differentiation of B cells and the production of antibodies.CD4⁺T cells play an important role in invasive fungal diseases（IFD）.However,the roles of Tfh cells,Tfr cells and their subsets in IFD are still unclear.By analyzing the changes in the frequency of Tfh cells,Tfr cells and their subsets in the peripheral blood of patients with IFD,the influence of these cells on disease progression was discussed,and the basis for the diagnosis,treatment,prognosis and vaccine development of invasive fungal infections was provided.Methods:The peripheral blood of 96 patients with fungal infection from a tertiary hospital from May 2020 to January 2022 was collected,and multicolor flow cytometry was used to detect Tfh cells,Tfr cells and their subsets in the peripheral blood of patients.At the same time,the peripheral blood of 80 normal physical examination patients was collected as a control,and the changes of Tfh cells,Tfr cells and their subsets in the normal control group and the invasive fungal disease group were compared;The collected96 cases were classified according to different strains,and the frequency of Tfh cells and Tfr cells in the control group and the fungal infection group with different strains was compared.Result:1.A total of 96 cases of IFD were collected in this study,50 males and 46 females;80normal healthy controls,40 males and 40 females.These included 21 Candida infections,48 Aspergillus infections,16 Cryptococcus infections,5 Pneumocystis infections,and 6other fungal infections.2.Compared with normal controls,the frequency of CD4⁺T cells was decreased in IFD patients.3.Compared with normal controls,in IFD patients,the frequency of CD4⁺CXCR5⁺CD25^lowCD127^{intermediate-high}Tfh cells was decreased,the frequency of Tfh1was decreased,Tfh2 cells were increased.4.Compared with normal controls,in IFD patients,the frequency of CD4⁺CXCR5⁺CD25^{intermediate-high}CD127^lowTfr cells was increased,the frequency of Tfr1-like was increased,Tfr2-like was decreased.5.Compared with normal controls,in the Candida infection case group,the frequency of CD4⁺T cells,Tfh1 cells,and Tfr2-like cells were decreased;in the Aspergillus infection group,the frequency of CD4⁺T cells,Tfh cells,Tfh1 cells,and Tfr2-like cells were decreased,and the frequency of Tfh2 cells,Tfr cells,and Tfr1-like cells were increased;in the Cryptococcus infection group,the frequency of CD4⁺T cells,Tfh cells,and Tfh1cells were decreased,and Tfr cells were increased;in the Pneumocystis infection case group,CD4⁺T cells were decreased;in other fungal infection case groups,Tfh cells were decreased,Tfr cells were increased.6.CD4⁺T cells are positively correlated with platelet count and lymphocyte count,Tfh1is negatively correlated with white blood cell count,neutrophil count,and neutrophil percentage,and Tfh1 is positively correlated with lymphocyte percentage;Tfh17 is positively correlated with the total number of white blood cells,neutrophil count;Tfr2-like was positively correlated with platelet count;Tfr17-like was positively correlated with the total number of leukocytes,and Tfr17-like was positively correlated with neutrophil count and neutrophil percentage.Conclusion:CD4⁺T cells,Tfh cells,Tfr cells and their subsets play an important role in the occurrence and progression of IFD patients,and provide a basis for the diagnosis,treatment and vaccine development of IFD.