| Objective: The study aims at investigatimg the changes of quantity,subtypes and functional markers expression and cytolytic function of NK cells in MDS patients,the effects of NK cells on the pathogenesis of MDS were also analyzed,Which will probably provide a basis for future cell therapy and target therapy of MDS.Background: Myelodysplastic Syndromes(MDS)is a group of cancerous bone marrow hematopoietic failure disease,characterized by cytopenias,inefficient hematopoiesis,dysplastic in one or more myeloid cell lineages and increased risk in of development of acute myeloid leukemia.Natural killer cells(NK cells)is a lymphocyte,accounting for peripheral blood lymphocytes in the total 10%-15%,because the cytoplasm contains astragalus particles,it is also known as large particles of lymph cell.Its immunophenotype is CD3-TCR-CD56+,is an important component of innate immunity and adaptive immunity,with early production of cytokines,chemokines and non-allergens can dissolve the target cells,so it plays an important role.in the body anti-virus,anti-tumor immunity.In recent years,with the progress of MDS pathogenesis,It has been reported that the number of NK cells is reduced,functional declined,and is associated with the progression of MDS.In this study,the number of NK cells and the receptor expression of NK cells in peripheral blood of patients with MDS were detected by flow cytometry.The cytotoxicity of NK cells was detected by co-culture method,and the correlation between MDS and related clinical indexes was also analyzed.Methods: 35 patients with MDS and 34 normal controls in Tianjin Medical University General Hospital from September 2015 to June 2016 were enrolled in this study.First section The percentage and quantity of NK cells(CD3CD56)?CD56NK cells(CD3-CD56brightCD16+)?CD56dimNK cells(CD3-CD56dimCD16-)in peripheral blood lymphocytes,the percentage of CD56 brightNK cells and CD56 dimNK cells in NK cells of MDS patients,and normal controls were detected by flow cytometry.The eppression of functional markers on NK cell surface,including activation receptors(NKp30/NKp46),inhibitory receptors(NKG2A)were analyzed based on isotype control with mouse Ig G1.After treatment,the above indicators were also detected.These indicators in high-risk MDS(H-MDS)and low-risk MDS(L-MDS)patients were also compared.The correlation between these changes and hematopoietie functions,including the number of neutrophil(ANC),and hemoglobin in peripheral blood and the primitive cells in bone marrow were evaluated.Second section CD3-CD56+NK cells were sorted from the blood of MDS patients and normals controls(cultured overnight with interleukin-2 1000 U/m L)and stained target cells were mixed at a ratio of 10:1 in a volume of 200 m L.After incubation for 6 h,cells were harvested and stained with propidium iodide.The cytolytic function was detected by flow cytometry.Results: First section(1)The percentage of NK cells and CD56 dim NK cells of MDS patients was significantly lower than that of normal controls(8.19±5.30 vs 13.81±5.96,P<0.001)and(7.95 ± 6.14 vs 12.78 ± 5.74,P=0.001).The percentage of CD56 bright NK cells was higher than that of controls(0.68±0.33 vs 0.53 ± 0.22,P<0.05).The percentage of NKT cells and T cells had no significant difference among the 2 groups.The percentage of CD56 dimNK cells in NK cells of MDS patients was significantly lower than that of controls(93.59 ± 3.56 vs 95.40 ± 2.48,P=0.024).The percentage of CD56 brightNK cells in NK cell of MDS patients was significantly higher than that of controls(6.41 ± 3.56 vs 4.59 ± 2.48,P=0.024).The ratio of CD56bright/CD56 dim in MDS was significantly higher than that of controls(7.0 ± 4.14 vs 4.88 ± 2.77,P=0.001).The quantity of NK,CD56 dimNK,CD56bright cells was significantly lower than that of normal control(125.16 ± 94.39 vs 295.86 ± 119.12,P<0.0001)?(127.88 ± 103.00 vs 281.34 ± 136.53,P<0.0001),(10.83 ± 4.53 vs 6.24 ± 4.66,P<0.001).(2)The expression of NKp30 and NKp46 of MDS patients was significantly 1ower than that of controls(74.35 ± 15.36 vs 84.89 ± 8.73,P=0.01)and(75.92 ± 18.77 vs 89.63 ± 9.12,P<0.0001),respectively.The expression of NKG2A in MDS patients had no significant difference with the controls(37.31 ± 19.59 vs 37.45 ± 14.24,P?0.0).(3)After treatment with 3 patients with MDS,percentage of NK cells and CD56 dim NK ells gradually recovered as the condition improved,and as the disease progressed,percentage of NK cells and CD56 dim NK cells decreased further.(4)In MDS group,the percentage of NK cells and CD56 dimNK cells in peripheral blood lymphocytes in H-MDS group was significantly lower than that of L-MDS group(5.41±0.97 vs 10.13±1.83,P=0.0)and(4.64±0.94 vs 8.81±1.14,P=0.02),respectively.The expression of NKG2 A,NKp30,NKp46 on NK cells had no significant difference with the two groups(31.97±2.74 vs 44.71±9.16,P=0.16),(71.26 ± 5.11 vs 77.44 ± 6.81,P=0.47),(75.70 ± 6.46 vs 78.70 ± 5.28,P=0.74),respectively.(5)The percentage of NK and CD56 dim NK cell was negatively correlated with the primitive cells in bone marrow(r=-0.53,P=0.04)and(r=-0.68,P=0.01),but positively correlated with ANC(r=0.52 and 0.53,P<0.01)and Hb(r=0.35 and 0.50,P<0.05).The expression of NKp46 was negatively correlated with primitive cells in bone marrow(r=0.584,P<0.05).Second section After co-culture,the apoptosis rate of K562 cell in MDS group was lower than the control group(7.73±4.0 vs 3.14±2.47,P=0.029).Conclusions: MDS patients with the reduced number,imbalanced subtype and decreased activated receptors of NK cells,leading to its lack of activation,decreased immune function,resulting in decreased immune surveillance function,can not effectively remove the MDS malignant clones,leading to disease progression. |
PDF Full Text Request