Phenotypic resistance properties of HIV-1 CRF01_AE strain main drug resistance mutations to integrase inhibitors / 中华微生物学和免疫学杂志

ABSTRACT

Objective:To analyze the effects of the main drug resistance mutations in the integrase (IN) region on the resistance of HIV-1 CRF01_AE strains, and compare the differences with subtype B strains.Methods:Seven IN region mutations or combined mutations (T66K, F121Y, Q148K, N155H, G118R, R263K, Q148K/N155H) were selected from the HIV drug resistance database of Stanford University in the United States, and introduced to the IN region of HIV-1 B subtype infectious clone pNL4-3 and CRF01_AE infectious clone pGX002 by seamless cloning, homologous recombination and point mutation. The mutant plasmids were transfected into 293T cells for virus packaging. The culture was expanded in MT2 cells and infectious titers were detected. Half maximal inhibitory concentrations (IC 50) of four integrase inhibitors (INSTIs), raltegravir (RAL), elvitegravir (EVG), dolutegravir (DTG) and bictegravir (BIC), against 14 mutant viruses were detected and compared with the IC 50 against the wild-type viruses. Results:B subtype and CRF01_AE plasmids carrying seven IN region mutations or combined mutations were successfully constructed, and 14 recombinant viruses were packaged with an infectious titer of 10 4-10 6 median tissue culture infective dose (TCID 50)/ml. The recombinant viruses replicated efficiently in MT2 cells. The concentrations of HIV-1 p24 antigen contained in the supernatants of cell culture reached 830-2 700 ng/ml. Five mutations or combined mutations (T66K, F121Y, Q148K, N155H, Q148K/N155H) caused CRF01_AE and B subtype strains to be highly resistant to RAL and EVG, resulting in an increase in the IC 50 by 200 times and 2 000 times or more as compared with the IC 50 against the wild-type viruses. The same mutation-caused fold changes of IC 50 of RAL and EVG against CRF01_AE were significantly lower than that of subtype B ( P<0.01). Q148K/N155H mutation caused B subtype and CRF01_AE to be highly resistant to DTG and BIC, with IC 50 increased by more than 50 times. Other mutations had little effects on the sensitivity to DTG and BIC. Conclusions:Fourteen HIV-1 strains carrying seven INSTI resistance mutations based on B subtype and CRF01_AE were constructed. Five mutations resulted in high resistance to RAL and EVG, and there was a high level of cross-resistance. Resistance to RAL and EVG caused by the same mutation was higher in B subtype than in CRF01_AE. The combined mutation of Q148K and N155H was associated with greater resistance to DTG and BIC, indicating that the genetic barrier of DTG and BIC resistance was high. DTG and BIC could effectively inhibit the strains carrying INSTI resistance mutations without obvious subtype difference.