摘要
目的观察第三方未成熟树突状细胞(imDC)负载同种异体抗原后对其免疫特性的影响。方法从健康足月新生儿脐血中分离单核细胞,采用重组人粒细胞巨噬细胞集落刺激因子 (rhGM-SCF)和重组人白细胞介素(rhIL)4联合培养7 d,诱导其分化成imDC,并通过光学显微镜和扫描电镜观察细胞形态、检测细胞表型及混合淋巴细胞反应(MLR);将培养的细胞与异体淋巴细胞抗原共同孵育,并给予共刺激分子阻断剂细胞毒性T淋巴细胞相关抗原4免疫球蛋白(CTLA-4Ig)处理,检测抗原负载前后的细胞表型变化,通过MLR比较致敏前后T淋巴细胞增殖的能力。结果 (1)培养后细胞具有典型的imDC特征,CD1α、CD83、CD80、CD86等成熟标志呈低表达,分别为 21．42％、0．59％、5．39％、3．85％;人类白细胞DR抗原(HLA-DR)的表达率为60．66％,MLR结果提示其不能刺激同种异体T淋巴细胞增殖。(2)负载抗原后的DC表现出成熟特性,CD1a、CD83、 CD80、CD86及HLA-DR表达明显增高,分别为65．51％、42．20％、56．45％、38．52％、76．44％(P< 0．05);能够刺激T淋巴细胞增殖[刺激指数(SI)>2．00]。(3)给予共刺激阻断剂CTLA-4Ig致耐处理后,SI由2．51下降到0．39,可明显抑制T淋巴细胞增殖。结论第三方imDC负载抗原后能表现出成熟特性;经CTLA-4Ig致耐处理,不能刺激未致敏T淋巴细胞增殖。有望诱导受体针对供者抗原的特异性免疫耐受。
Objective To investigate the influence of allogeneic antigen loading on the immune characteristics of the third party immature dendritic cells （ inDCs）. Methods Mononuclear cells were isolated from the cord blood of healthy infants. They were induced and differentiated into immature dendritic cells with rhGM-SCF and rhIL- 4 for 7 days. Then the morphology of the cells was examined with light microscope and scanning electron microscope, their immunological phenotype was examined with flow cytometry, and MLR was also performed. The cells were co-cultured with the allogeneic lymphocyte antigen. Then parts of the DCs loaded with allogeneic antigen were treated by co-stimulatory blocking agent （ CTLA- 4Ig）. The phenotype of DCs was examined and compared before and after incubation, and T lymphocyte proliferation before and after sensitization by mixed lymphocyte reaction（MLR）. Results （1） The cells exhibited the typical morphology of DC, with low expression of CD1α（21.42% ） ,CD83（0. 59% ） ,CD80（5.39% ） and CD86 （3.85%）. The expression rate of HLA-DR was 60.66% , and MLR results indicated that they did not have the ability to induce the stimulation of allogeneic naive T lymphocyte proliferation. （2） The DCs loaded with allogeneic antigen exhibited mature property, with high expression of CD1α （ 65. 51% ） , CD83 （42. 20% ） , CD80（56.45% ） , CD86 （38.52%） and HLA-DR （ 76.44% ） , which were capable to stimulate T lymphocyte proliferation（ SI 〉 2.00）. （3） After treatment with CTLA- 4Ig, the SI decreased from 2.51 to 0. 39, and the T cell proliferation was suppressed significantly. Conclusion The third party imDCs exhibited mature characteristics after loading with allogeneic antigen. They lose the property to stimulate the proliferation of allogeneic naive T lymphocytes after CTLA- 4Ig treatment, and it may lead to induction of antigen-specific immune tolerance to donor in the recipient.
出处
《中华烧伤杂志》
CAS
CSCD
北大核心
2006年第2期113-116,共4页
Chinese Journal of Burns
基金
国家自然科学基金资助项目(30271341)
关键词
树突细胞
抗原
阻断疗法
免疫耐受
Dendritic cells
Antigen
Blocking therapy
Immune tolerance
