Establishment of a real-time PCR assay for detection of the activity of HIV-1 reverse transcriptase

Objective To reconstruct the initiative procedure of HIV-1 reverse transcription in vitro and establish a methodology of assessing activity of HIV-1 reverse transcriptase (RT) with real-time PCR Methods The tRNALys-3 gene was amplified from genome in healthy individuals through polymerase chain reaction (PCR), and then T7 transcription promoter was added in 5'-terminal of the tRNALys-3. The tRNA[Lys-3 cRNA product was obtained by applying T7 RNA polymerase through a transcription reaction. The 5'-LTR-PBS DNA was also obtained by transcription reaction from the HIV-1 infectious clone and inserted into pGEM-T easy vectors. 5'-LTR-PBS cRNA was obtained by applying SP6 RNA polymerase whose combining site was located in pGEM-T easy vectors. Then the two RNA samples was catalyzed by two kinds of standard reverse transcriptases (SuperScript Ⅲ and HIV-1 standard reverse transcriptase, respectively) and the cDNA was synthesised. The relative activity of RT was determined with the real-time PCR. Results The tRNALys-3 primer and the SP6-5'-LTR-PBS RNA were procured accurately, whose length were 93bp and 872 bp, respectively. After the following serial dilution of Super Script Ⅲ and HIV-1 standard reverse transeriptase:1 : 10, 1: 100, 1:1 000, 1:10 000, each step of reverse transcription process worked successfully. Real-time PCR results showed that Ct values of the two groups were 13.9, 18. 3, 20. 9, 24. 9 and 20. 4, 25. 5, 28. 7, 32. 5 respectively. Conclusion A novel real-time PCR method is developed to assay the RT activity directly through reconstructing the initiation of HIV reproduction, which may be helpful for clinical management, screening of new antiretroviral drugs, and drug resistance test. Key words: HIV-1; HIV reverse transcriptase; Polymerase chain reaction