| 摘要: |
| 【目的】 探讨细胞毒性T细胞（CTL）表位肽SIINFEKL浓度和树突状细胞（DC）数量对CD8+ T细胞活化和增殖的影响。【方法】 用小鼠重组粒细胞集落刺激性生物因子（GM-CSF）和IL-4诱导骨髓细胞来源的DC增殖和分化，将所得成熟树突状细胞（maDC）和SIINFEKL抗原肽，与免疫磁珠法分离的OT-I小鼠CD8+T细胞共培养。用不同质量浓度的SIINFEKL（100，10，1，0.1，0.01和0.001 ng/mL）或不同数量的DC（DC/T比例分别为1/20和1/5）与CD8+T细胞共培养，刺激CD8+ T细胞增殖分化。于共培养不同时间收集细胞，流式细胞术测定CD8+ T细胞的数量、分裂速度、细胞表面活化分子的表达丰度，碘化丙叮（PI）染色测定细胞活力。【结果】 在任一DC/T比例下，SIINFEKL浓度过低，均不能引起CD8+ T细胞的充分增殖，而高于CD8+ T细胞最佳增殖浓度的SIINFEKL则导致CD8+ T细胞数量减少；在SIINFEKL质量浓度为0.001~0.1 ng/mL时，增加DC数量能促进CD8+ T细胞的扩增；而SIINFEKL质量浓度为1~100 ng/mL时，提高DC数量反而导致CD8+ T细胞数量减少；高浓度抗原和DC数量能有效诱导CD8+ T细胞的活化和分裂增殖，但过量刺激会使细胞死亡，导致CD8+ T细胞数量减少。【结论】 CD8+ T细胞的增殖受DC数量和抗原肽浓度的共同调节，要获得持久有效的CD8+ T细胞免疫，必须保证CD8+ T细胞得到足够的抗原信号，同时避免抗原信号过强导致的细胞活化后死亡。 |
| 关键词: 抗原浓度 树突状细胞 CD8+ T细胞 |
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| Influence of antigen dose and DC number on CD8+ T cell differentiation and proliferation of OT-I ransgenic mice |
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| Abstract: |
| 【Objective】The study was to investigate the influence of peptide SIINFEKL concentration and Dendritic Cell (DC) number on primary CD8+ T cell differentiation and proliferation. 【Method】 Bone marrow derived DCs were generated from bone marrow cells in the presence of GM-CSF and IL-4. OT-I mice CD8+ T cells were isolated by anti-mCD8 conjugated magnetic microbeads, and stimulated by SIINFEKL peptides and mature dendritic cells（maDC）.Serial diluted peptides SIINFEKL（100，10,1,0.1,0.01,0.001 ng/mL） and different amounts of DCs（DC/T ratio of 1/20,1/5） were co-cultured with CD8+ T cells to stimulate the activation of CD8+ T cells.Then the cell number,division rate and activated surface marker of co-cultured CD8+ T cells were analyzed by flow cytometry,and cell vitality was measured by propidium iodide (PI) stain. 【Result】 Deficient peptides result in insufficient CD8+ T cell proliferation,while excess peptides impair live CD8+ T cell number.CD8+ T cell proliferation was more pronounced when more DCs were used to present peptides ranging from 0.001 ng/mL to 0.1 ng/mL and fewer DCs were used to present peptides ranging from 1 ng/mL to 100 ng/mL.High concentration of peptide antigen or large numbers of DCs lead to the fully activation and division of CD8+ T cells but followed a remarkable decrease in CD8+ T cell number,which may be caused by activation induced cell death (AICD). 【Conclusion】 Effective CD8+ T cell activation and proliferation depend on the optimal intensity of antigenic signals,which is controlled by the amount of both peptide antigen and DCs.To induce effective and prolonged cellular immune responses,the antigenic stimulation should meet the minimum requirement of activation,and elaborately evaluate to avoid AICD. |
| Key words: antigen concentration DC CD8+ T cell |
