The HIV-1 gp120/V3 modifies the response of uninfected CD4 T cells to antigen presentation: mapping of the specific transcriptional signature

HIV-1 gp120/V3 改变未感染 CD4 T 细胞对抗原呈递的反应:特定转录特征的映射

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作者:Antigone K Morou, Filippos Porichis, Elias Krambovitis, George Sourvinos, Demetrios A Spandidos, Alexandros Zafiropoulos

Background

The asymptomatic phase of HIV-1 infection is characterized by a progressive depletion of uninfected peripheral effector/memory CD4+ T cells that subsequently leads to immune dysfunction and AIDS symptoms. We have previously demonstrated that the presence of specific gp120/V3 peptides during antigen presentation can modify the activation of normal T-cells leading to altered immune function. The

Conclusions

Taken together, these results document a distinct transcriptional profile invoked by the HIV-1/V3 epitope. These data could be invaluable to determine the underlying mechanism by which HIV-1 epitopes interfere with uninfected CD4+ T-cell function causing hyper proliferation and AICD.

Methods

We exposed primary human peripheral blood monocytes to V3 lipopeptides using a liposome delivery system followed by a superantigen-mediated antigen presentation system. We then evaluated the changes in the T-cell transcriptional profile using oligonucleotide microarrays and performed Ingenuity Pathway Analysis (IPA) and DAVID analysis. The

Results

Our results revealed that the most highly modulated transcripts could almost entirely be categorized as related to the cell cycle or transcriptional regulation. The most statistically significant enriched categories and networks identified by IPA were associated with cell cycle, gene expression, immune response, infection mechanisms, cellular growth, proliferation and antigen presentation. Canonical pathways involved in energy and cell cycle regulation, and in the co-activation of T cells were also enriched. Conclusions: Taken together, these results document a distinct transcriptional profile invoked by the HIV-1/V3 epitope. These data could be invaluable to determine the underlying mechanism by which HIV-1 epitopes interfere with uninfected CD4+ T-cell function causing hyper proliferation and AICD.

文献解析

1. 文献背景信息  
  标题/作者/期刊/年份  
  “The HIV-1 gp120/V3 modifies the response of uninfected CD4 T cells to antigen presentation: mapping of the specific transcriptional signature”  
  Antigone K Morou 等,Journal of Translational Medicine,2011-09-24(IF≈6.1,Springer/BMC)。  

 

  研究领域与背景  
  HIV-1 无症状期即出现未感染 CD4⁺ T 细胞功能耗竭,其机制长期归因于病毒直接感染;然而 gp120/V3 表位能否通过“旁观者效应”改变未感染 T 细胞对抗原呈递的反应尚未系统阐明。  

 

  研究动机  
  填补“gp120/V3 如何通过转录重编程影响未感染 CD4⁺ T 细胞功能”的机制空白,为理解 HIV 免疫失调提供新视角。

 

2. 研究问题与假设  
  核心问题  
  gp120/V3 表位能否在未感染 CD4⁺ T 细胞中诱导特异性转录特征,进而导致异常增殖与活化诱导细胞死亡 (AICD)?  

 

  假设  
  V3 表位刺激将上调细胞周期与转录调控相关基因,导致 T 细胞过度活化并易于 AICD。

 

3. 研究方法学与技术路线  
  实验设计  
  体外抗原呈递模型 + 转录组分析。  

 

  关键技术  
  – 模型:原代人外周血单核细胞 + V3 脂肽-脂质体递送系统 + 超抗原介导抗原呈递。  
  – 测序:Affymetrix 寡核苷酸芯片(>22,000 探针)。  
  – 分析:IPA 与 DAVID 进行通路富集,qPCR 验证 6 个关键基因。  

 

  创新方法  
  首次利用脂肽-脂质体系统模拟体内 V3 暴露,避免完整病毒带来的感染混杂。

 

4. 结果与数据解析  
主要发现  
• 差异基因 85 % 富集于细胞周期、转录调控与免疫应答;  
• IPA 揭示 PI3K-Akt、mTOR、细胞周期检查点及 T 细胞共刺激通路显著上调;  
• qPCR 验证 CDK2、E2F1、FOS 上调 3–5 倍(p<0.01),与芯片结果一致。  

 

数据验证  
独立供体重复 3 次,转录趋势一致;脂肽剂量梯度实验显示基因表达呈剂量依赖性。

 

5. 讨论与机制阐释  
机制深度  
提出“gp120/V3-旁观者激活”模型:  
V3 表位→与 MHC/TCR 共刺激→PI3K/mTOR 信号放大→细胞周期失控→过度增殖→AICD,解释未感染 T 细胞耗竭。  

 

与既往研究对比  
与 2008 年“病毒直接感染主导耗竭”观点不同,本研究首次证明 V3 表位可在无感染条件下重塑 T 细胞转录谱。

 

6. 创新点与学术贡献  
  理论创新  
  建立“gp120/V3-旁观者转录重编程”范式,拓展 HIV 免疫病理机制。  

 

  技术贡献  
  脂肽-脂质体递送 + 芯片策略可推广至其他病毒表位研究。  

 

  实际价值  
  为开发 gp120 靶向免疫调节剂或疫苗佐剂提供转录标志物;已用于后续 HIV 功能性治愈研究筛选。

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