Autophagy is involved in T cell death after binding of HIV-1 envelope proteins to CXCR4
J. Clin. Invest. Lucile Espert, et al. 116:2161 doi:10.1172/JCI26185 [Go to this article.]

Figure 2
Autophagy is induced by cell-expressed Env, and Beclin 1 is accumulated during this process. (A) UC blood CD4⁺ T lymphocytes were purified by negative selection using the CD4⁺ Rosette separation technique. Cells were cocultured for 3 days with HEK or HEK.Env or treated with 1 μM Rapa and examined by TEM. Autophagic (vacuolated) cells were defined as cells that had 5 or more autophagic vacuoles. The percentage of autophagic cells and the number of vacuoles in the target cell sections were analyzed from at least 100 randomly chosen TEM fields by 2 investigators. Scale bars: 1 μm; 250 nm (indicated enlargements). (B) UC blood CD4⁺ T cells were transfected with GFP-LC3, cocultured with HIV_NL4-3-infected or uninfected CEM cells, and examined by epifluorescence. Data are representative of 3 independent experiments; more than 100 cells were counted by 2 investigators. Cells with autophagosomes were defined as cells that had 5 or more LC3 spots in the cytoplasm. Magnification shown. (C) Beclin 1 expression was analyzed in UC blood CD4⁺ T cells cocultured with effector HEK cells with or without Env expression. Fold induction was calculated as the intensity of the Beclin 1 immunoblot obtained in cells cocultured with effector cells expressing Env compared with effector cells that do not express Env. Ratios were normalized to that obtained with anti-actin Ab. Data are representative of at least 3 independent experiments. **P < 0.01; ***P < 0.001.