Effect of Rac1-dependent cell signaling on production of Env-deleted HIV-1 particles. (A to D) Effect of Rac1, Dia1, Wave2, IRSp53, or Arp3 depletion on production of mature particles. Jurkat T cells were transfected with pNL4.3ΔEnv and with the siRNA control or siRNA against Rac1, Dia1, Wave2, IRSp53, or Arp3. (A) Immunoblot analysis of pr55Gag and CAp24 in cell lysates and in virus particles. Tubulin was used as a loading control. (B) Extracellular virus production measured by quantification of immunoblot images, corresponding to the ratio of extracellular CAp24 to intracellular pr55Gag and CAp24. Bars show mean values and standard deviations resulting from two independent experiments. The statistical significances of differences were calculated by an unpaired t test. **, P value of <0.01; *, P value of <0.05. (C) Cell viability measured by using trypan blue. (D) Quantification of protein depletion after siRNA treatment by using ImageJ software, relative to the tubulin loading control. Bars show mean values and standard deviations resulting from three independent experiments. (E to H) Effect of Rac1, Dia1, Wave2, IRSp53, or Arp3 depletion on production of mature particles in PBLs. PBLs were transfected with pNL4.3ΔEnv and with the siRNA control or siRNA against Rac1, Dia1, Wave2, IRSp53, or Arp3. (E) Immunoblot analysis of HIV-1 pr55Gag and CAp24 in cell lysates and in virus particles. Tubulin was using as a loading control. (F) Extracellular virus production calculated as described above for panel B. Bars show mean values and standard deviations resulting from two independent experiments. (G) Cell viability measured by dead cell counting using trypan blue. (H) Quantification of protein depletion after siRNA treatment.