G to A hypermutation in newly synthesized DNA of viruses generated from cells containing CEM15. a, DNA sequence alignment in HIV-1 U3-R region. The clones with the most-identical sequences from the total clones (n = 8) are listed. Viruses were from 293T (top) cells or passaged in SupT1 (bottom) cells. In the top panel, the rows are: (1) wild-type viruses, with CEM15, to infect C8166 cells; (2) wild-type viruses, with CEM15, to process ERT; (3) wild-type viruses, without CEM15, to infect C8166 cells; (4) Δvif viruses, with CEM15, to infect C8166 cells; (5) Δvif viruses, with CEM15, to process ERT; (6) Δvif viruses, without CEM15, to infect C8166 cells. In the bottom panel, the rows are: (7) wild-type viruses, without CEM15; (8) wild-type viruses, with CEM15. b, Comparison of G to A mutation frequency in newly synthesized DNA (301 nucleotides in U3-R-U5 region, n = 8). The G to A mutation frequency of Δvif viruses from 293T or SupT1 cells containing CEM15 is significantly higher than that of others (asterisk, P < 0.001, t-test). c, Comparison of G to A mutation frequency in the viral DNA after passage (n = 8). The G to A mutation frequency of wild-type viruses passaged in SupT1 cells containing CEM15 is significantly higher than that in SupT1 cells without CEM15 (asterisk, P < 0.001, t-test). d, The wild-type virions, after various passages in SupT1 cells containing CEM15, were purified. After normalization with HIV-1 p24, the virion-associated Vif protein was detected by western blot.