发布: 2019年02月20日第9卷第4期 DOI: 10.21769/BioProtoc.3168 浏览次数: 5952
评审: Marielle CavroisDaniela BoehmPooja Saxena
相关实验方案
TZA, 一种基于敏感报告因子细胞学检测方法, 可用于准确快速量化静息CD4+ T细胞中可诱导的且复制能力强的潜伏HV-1
Anwesha Sanyal [...] Phalguni Gupta
2019年05月20日 7018 阅读
Abstract
Upon entry into a host cell, the HIV-1 virus undergoes a series of critical early replication events including reverse transcription, nuclear import, and integration of its cDNA into the host genome. Molecular assays used to detect and analyze changes in HIV-1 early phase replication events are valuable tools in developing potential antiretroviral drugs, as well as studying the pathogenesis of HIV. Described here are the molecular assays utilized to detect and quantify HIV-1 early, intermediate, and late reverse transcription (RT) products. In addition to this, protocols for quantifying HIV-1 2-LTR circle DNA and proviral DNA after integration are also included. In these protocols, the optimized TaqMan Real-time PCR reagent is used to increase assay sensitivity and reproducibility. Furthermore, a nested PCR is applied to HIV-1 integration quantification with increased accuracy.
Keywords: HIV-1 (HIV-1)Background
After binding to the receptor and fusing to the host cell’s lipid bilayers, the HIV-1 nucleoprotein complex first enters the cytoplasm, crosses the nuclear envelope, and finally integrates the reverse-transcribed HIV genome into that of the host cell. During this early phase of replication, HIV-1 converts its single-stranded RNA genome into linear double-stranded DNA in cytoplasm by an intricate reverse transcription process (Hu and Hughes, 2012). After nuclear import, some of these linear viral genomes are integrated into the host chromatin. These are termed proviruses. The remaining cDNA that fails to integrate is circularized into either 1-LTR circle DNA or 2-LTR circle DNAs (Sloan and Wainberg, 2011). HIV-1 can counteract various host restriction factors that can interfere with its early phase replication events (Zheng et al., 2012). Molecular assays used to detect and analyze changes in HIV-1 early phase replication events are valuable tools in studying HIV pathogenesis and in developing potential antiretroviral drugs. We report here methods to quantitatively analyze several critical events during HIV-1 early phase replication by using Real-time PCR. The early, intermediate and late stages of reverse transcription events are represented by the initiation of HIV-1 minus strand DNA synthesis, the elongation of minus-strand DNA synthesis following transfer of minus strand DNA, and the synthesis of complete double-stranded linear viral DNA after plus-strand DNA transfer respectively. Given that 2-LTR circles are exclusively found in the cell nucleus, they have become a useful marker of viral nuclear import (Sloan and Wainberg, 2011). As shown in Figure 1, a nested PCR is utilized to quantify HIV-1 integration with increased sensitivity and specificity. Since Alu sequences are the most abundant repetitive DNA, containing over one million copies dispersed throughout the human genome, the 1st round of PCR is designed to amplify a fragment between the integrated HIV-1 gag gene and the host genomic Alu sequence element. Both forward and reverse Alu PCR primers are used in 1st round Alu-gag PCR, since either orientation of Alu sequence can exist in human genome. To avoid the amplification of unintegrated HIV-1 cDNA, the 5’ end of 1st PCR gag R primer is tagged with a unique R sequence. Only the 1st round PCR amplicons containing the R sequence can be used as templates in the 2nd round of Real-time PCR. The optimized TaqMan Real-time PCR reagent is used to increase assay sensitivity and reproducibility. All PCR primers, probe sequences, and their amplicon locations are listed in Table 1.
Figure 1. A nested PCR for quantification of HIV-1 integration
Table 1. A list of sequences of PCR primers and probes
Materials and Reagents
Equipment
Software
Procedure
文章信息
版权信息
© 2019 The Authors; exclusive licensee Bio-protocol LLC.
如何引用
Graf, L., Moran, S. P., Ro, S., de Noronha, C. M. and Shi, B. (2019). Analysis of Early Phase HIV-1 Replication and Integration Events by Using Real-time PCR. Bio-protocol 9(4): e3168. DOI: 10.21769/BioProtoc.3168.
分类
微生物学 > 微生物细胞生物学 > 基于细胞的分析方法
分子生物学 > DNA > DNA 定量
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