tailieunhanh - Báo cáo y học: " A Leu to Ile but not Leu to Val change at HIV-1 reverse transcriptase codon 74 in the background of K65R mutation leads to an increased processivity of K65R+L74I enzyme and a replication competent virus"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: A Leu to Ile but not Leu to Val change at HIV-1 reverse transcriptase codon 74 in the background of K65R mutation leads to an increased processivity of K65R+L74I enzyme and a replication competent virus | Chunduri et al. Virology Journal 2011 8 33 http content 8 1 33 J VIROLOGY JOURNAL RESEARCH Open Access A Leu to Ile but not Leu to Val change at HIV-1 reverse transcriptase codon 74 in the background of K65R mutation leads to an increased processivity of K65R L74I enzyme and a replication competent virus 12 1 3 HimaBindu Chunduri David Rimland Viktoria Nurpeisov Clyde S Crumpacker Prem L Sharma 1 Abstract Background The major hurdle in the treatment of Human Immunodeficiency virus type 1 HIV-1 includes the development of drug resistance-associated mutations in the target regions of the virus. Since reverse transcriptase RT is essential for HIV-1 replication several nucleoside analogues have been developed to target RT of the virus. Clinical studies have shown that mutations at RT codon 65 and 74 which are located in P3-P4 linkage group of finger sub-domain of RT are selected during treatment with several RT inhibitors including didanosine deoxycytidine abacavir and tenofovir. Interestingly the co-selection of K65R and L74V is rare in clinical settings. We have previously shown that K65R and L74V are incompatible and a R K reversion occurs at codon 65 during replication of the virus. Analysis of the HIV resistance database has revealed that similar to K65R L74V the double mutant K65R L74I is also rare. We sought to compare the impact of L V versus L I change at codon 74 in the background of K65R mutation on the replication of doubly mutant viruses. Methods Proviral clones containing K65R L74V L74I K65R L74V and K65R L74I RT mutations were created in pNL4-3 backbone and viruses were produced in 293T cells. Replication efficiencies of all the viruses were compared in peripheral blood mononuclear PBM cells in the absence of selection pressure. Replication capacity RC of mutant viruses in relation to wild type was calculated on the basis of antigen p24 production and RT activity and paired analysis by student t-test was performed among RCs of .