Figure 1.

Autophagy is required for optimal HIV yields in macrophages. (A) Pharmacological blockage of autophagy inhibits release of infectious virions. Human peripheral blood MDM were infected with SF162 HIV-1 for 10 d, then washed and incubated with control media or 3MA for 4.5 h. Culture supernatants containing HIV particles were used for a MAGI infectivity assay as described in Materials and methods. (B) Relative viral release was calculated as a ratio of extracellular-to-intracellular Gag-derived core antigen capsid protein CA (p24) and normalized to the control. (C) Western blot showing siRNA knockdown of Beclin 1, 7 d after transfection in MDM. (D) Human MDM were transfected with siRNA to Beclin 1 and infected with SF162 HIV-1 for 7 d, then p24 yields were quantified. (E) Western blots showing siRNA knockdown of Beclin 1 and Atg7 48 h after transfection in U937 cells. (F) Knockdown of autophagy regulators Atg7 and Beclin 1 inhibits basal viral yields released from macrophages. U937 cells were cotransfected with Beclin 1 or Atg7 siRNA and pMSMBA (a clone of NL4-3). Data indicate means; error bars indicate ±SEM (n ≥ 3). *, P < 0.05; **, P < 0.01; †, P > 0.05 (analysis of variance [ANOVA]). (G) U937 cells were knocked down for Beclin 1 expression and infected with VSV-G–pseudotyped HIV. Cell lysates were performed for Gag processing analysis. *, P < 0.05, paired t test.