Ultrastructural Analysis of HIV-1-Infected PBMCs

For TEM analysis, HIV-1-infected PBMCs treated or not with 100 ng/mL of IL-27 during 48 h were fixed in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.2) for 1 h at 25°C and postfixed with a solution of 1% OsO₄ containing 0.8% potassium ferricyanide and 2.5 mM CaCl₂ in the same buffer for 20 min at 25°C. Then, the samples were dehydrated in an ascending acetone series and embedded in Polybed 812 resin (Polysciences, USA). Ultrathin sections were obtained, stained with uranyl acetate and lead citrate, and examined with the transmission electron microscope JEM 1011 (Jeol, Tokyo, Japan) at the Fiocruz Electronic Microscopy Platform.