Th1/Th2细胞对再生障碍性贫血CD34^+细胞体外扩增和集落形成的影响

The effects of Th1/Th2 cells on in vitro expansion and colony forming of CD34^+ cells of aplastic anemic patient

目的探讨Th1/Th2细胞平衡偏离及平衡回复对重型再生障碍性贫血(sAA)骨髓CD34+细胞体外扩增和集落生成的影响。方法以1例确诊的sAA患者为研究对象。(1)分离骨髓单个核细胞,用免疫磁珠法富集CD34+细胞、CD4+(Th)细胞。(2)以流式细胞术(FCM)检测CD4+细胞中Th1、Th2细胞比例。(3)扩增CD34+细胞并再次富集以获足量CD34+细胞,分为4组对照组;Th细胞作用组;Th细胞+IFN-γ作用组;Th细胞+IL-4作用组。(4)各组扩增培养10d,继以集落生成试验,测定各组CD34+细胞扩增率和集落产率。(5)患者经免疫抑制治疗后随访,用FCM监测Th1/Th2细胞比。结果(1)患者经5个月治疗获缓解。(2)缓解前、后Th1/Th2比分别是22.47和12.27,正常对照组为8.98±4.45。(3)CD34+细胞扩增率,以对照组最高,其次为Th细胞+IL-4组、Th细胞组,Th细胞+IFN-γ组的最低。(4)各组CD34+细胞集落产率与其扩增率数值平行相关,即对照组最多,其次为Th细胞+IL-4组、Th细胞组,Th细胞+IFN-γ组的最少。结论Th1细胞反应亢进直接抑制sAA患者CD34+细胞在体外的自我更新和增殖分化,IL-4能拮抗这种造血抑制效应,这可能是通过调节Th1/Th2平衡而间接实现的。

AIM： To investigate the effects of both Th1/Th2 imbalance and its re-attainment on in vitro expansion and hematopoiesis of CD34^＋ cells from a severe aplastic anemia （sAA） patient. METHODS： A preliminary-diagnosed sAA patient was studied. （ 1 ） Bone marrow mononuclear cells （BMMNC） were isolated and CD34^＋ and CD4^＋ cells were enriched by magnetic beads respectively. （2）The Th1/Th2 cell ratio within CD4^＋ subset was detected by flow cytometery （ FCM ）. （ 3 ） Enriched-CD34^＋ cells were expanded and re-enriched for enough cells to be divided into four groups： control, Th cell treatment, Th cell and IFN-γ treatment, and Th cell and IL-4 treatment, respectively. （4） After expansion for 10 d, colony-forming unit assay was performed on cells in each group. （5）Patient＇s Th1/Th2 ratio was followed up by FCM after immunotherapy. RESULTS： （ 1 ） Symptom remission was achieved after therapy for 5 moth. （2）Th1/Th2 cell ratio of the patient before and after remission was 22.47 and 12.27, respectively, while that of healthy controls was 8.98 ± 4.45. （3） The CD34^＋ cell expansion rates as well as CFU numbers, from high to low, were ranked as control, Th cell and IL-4 contained group, Th cell contained, and Th cell and IFN-γ contained group. CONCLUSION： Predominant Th1 cells seem to directly inhibit the self-renewal, proliferation and lineage differentiation of CD34^＋ cells in vitro, which can be counteracted by IL-4, probably mediated by switching Th1/Th2 balance.