(A) Lysates of MT4 cells infected with recombinant Sendai virus (SeV) expressing hemagglutinin (HA)-tagged human TRIM5α with 249D (lane D) and with 249G (lane G) were visualized by western blotting with an antibody against HA. Representative results of three independent experiments are shown. (B) MT4 cells were infected with SeV expressing TRIM5α lacking the PRYSPRY domain [SPRY(−); white circles], MT4-derived human TRIM5α (249D; black squares), human TRIM5α (249G; black triangles), or rhesus monkey TRIM5α (Rh; black circles). Nine hours after SeV infection, cells were inoculated with HIV-1 strain NL4-3 or HIV-2 strain GH123, and culture supernatants were periodically assayed for levels of p24 or p25, respectively. Data points are means for triplicate samples with SD. Three and six days after infection, statistically significant differences (p<0.05) of HIV-1 and HIV-2 growth were observed between human TRIM5α (249D) and human TRIM5α (249G) by unpaired t test. Representative data of at least three independent experiments are shown.