Cells and virus

MT4 lymphocytes were grown in RPMI 1640 medium supplemented with 10% heat-inactivated FBS at 37°C in 5% CO₂. Cells were used at the exponential phase of growth and with viability at least 95%. The Countess™ automated Cell Counter (Thermo Fisher Scientific, Waltham, MA, USA) was used to determine cell counts and viability.

Stock virus was prepared by harvesting supernatant of HIV-infected MT4 lymphocytes at day 5 post-infection. The virus was titrated by conventional methods and stored at −80°C until use.53 All work involving HIV culture was performed in the appropriate biosafety conditions.54,55