Transduced CEMss-CCR5 cells were then infected with HIV-1 strains Bru-3 and Bru-Yu2 at multiple of infection of 0.01 as described before [23] and cultured in the complete DMEM medium for 75 to 105 days, except for cells transduced with secretory scFvs (AB65 and X5) and infected with Bru-3 (the culture of these cells was terminated on day 27 post infection). Here, CCR5 is linked to infection.