蛋白转导域介导BCR/ABL抗原对CML患者T细胞的活化作用

目的：研究蛋白转导域(PTD)介导的BCR／ABL抗原对慢性髓细胞白血病(CML)患者T细胞的特异性活化作用。方法：利用基因工程技术，将PTD基因与CML b3a2 bcr／abl基因融合并原核表达。将纯化的PTD—BCR／ABL融合蛋白与CML患者外周血单个核细胞(PBMC)体外共孵育，用流式细胞仪分别检测CD4^ 、CD8^ T细胞上活化抗原CD25的表达。结果：终浓度为100mg／L的PTD—BCR／ABL抗原体外刺激4d后，10例CML患者中，5例表现为CD8^ T细胞活化，2例表现为CD4^ T细胞活化，其中有1例CD8^ 和CD4^ T细胞同时活化；而作为对照的BCR／ABL抗原刺激组无一例表现为CD8^ 或CD4^ T细胞活化。结论：PTD能将外源性BCR／ABL抗原转导入抗原呈递细胞内，加工呈递后激活抗原特异性CD8^ 及CD4^ T细胞，为CML特异性CD8^ 、CD4^ T细胞的体外活化及细胞免疫治疗开辟一条新的途径。

Activation effects of BCR/ABL antigen on CML T cells mediated by protein transduction domain

AIM: To study the activation effect of BCR/ABL antigen on T cells from CML patients mediated by protein transduction domain (PTD). METHODS: The fused plasmid containing PTD gene and b3a2 bcr/abl gene of CML was constructed by genetic engineering technique and was expressed in E.coli . The PBMCs from CML patients were stimulated in vitro with purified PTD BCR/ABL antigen and then expression of the activation antigen CD25 on CD8 + and CD4 + T cells after stimulation was detected by flow cytometry (FCM). RESULTS: After stimulation with 100 mg/L of PTD BCR/ABL antigen (final concentration) for 4 days in vitro , CD8 + T cells were activated in 5 of 10 CML patients and CD4 + T cells were activated in 2 of 10 patients. Both CD8 + and CD4 + T cells were activated simultaneously in one of them. However, neither CD4 + nor CD8 + T cells was activated in BCR/ABL antigen stimulation group as control. CONCLUSION: Using a PTD mediated antigen transduction system, exogenous BCR/ABL antigen can be transferred into APCs and be processed and presented onto surface of APCs to activate Ag specific CD8 + and CD4 + T cells in vitro . The strategy outlined in this paper may provide a new approach for priming Ag specific CD8 + and CD4 + T cells in vitro and immunotherapy of CML.