CD3／CD28协同刺激诱导抵抗和清除HIV-1感染的检验研究与细胞亚群分析

目的通过CD3／CD28抗体协同刺激活化原代CD4^＋ T细胞，以复制具有抵抗和清除HIV-1能力的“Levine现象”，建立相关机理研究的实验模式，分析效应细胞的亚群特征。方法从外周血单个核细胞中分选高纯度的CD4’T细胞，以PHA／IL-2为对照，经CD3／CD28抗体刺激培养后，以CD45RO、CD62L和CCR7进行单细胞流式分析，鉴定细胞亚群及CCR5、CXCR4表达水平，以实时荧光定量法测定培养上清中的病毒载量。结果CD3／CD28抗体刺激下CD4^＋ T细胞明显增殖活化，原态细胞减少，明显转为记忆细胞表型，特别是M2亚群和TCM亚群细胞增多，未发现典型的TEMRA亚群。与PHA／IL-2相反，CD3／CD28抗体明显下调CCR5，并使早期感染者的病毒载量始终维持低于检出线水平（〈50IU／m1）。结论本研究以“Levine现象”为线索，验证和复制了诱导靶细胞抵抗和清除HIV-1感染的研究体系，为进一步探索新的防治HIV／AIDS的细胞分子机理奠定了基础。

CD3/CD28 costimu lation-induced resistance to HIV-1 infection and cell subsets analysis

Objective To set up a novel research model by reproducing “Levine phenomenon” which harbours an unusual anti-HIV/AIDS activity. Methods CD4 ＋ T cells were purified from peripheral blood mononuclear cells by negative selection using MACS system. Cells were then stimulated with CD3/CD28 antibodies immobilized on polystyrene beads with PHA/IL-2 as control for 6 days. Cellular phenotypes were analyzed by flow cytometry. Viral load of HIV-infected cells in culture was monitored by Real-time PCR. Results Costimulated cells showed higher expression of activation markers and switched their naive phenotypes to memory predominance with decreased CCR5 expression. With continuous costimulation,in viral production cells from an early infected individual was suppressed to undetectable level. Conclusion The anti-HIV system described by Levine et al can be readily estabhshed de novo in house and serves as a useful model for novel antiviral mechanisms.