Intercellular HIV-1 Nef transfer.

Nef.GFP-expressing Jurkat (0.5 x 10⁶) were co-cultured with 0.5 x 10⁶ of SP-DilC-labeled Jurkat (A, top panels), SP-DilC-labeled THP-1 (B), or HPA (C) in a volume of 200 μl medium in a 24-well plate (i.e., at a cell density of 0.5 x 10⁶/ml) for 16 hr. GFP-expressing Jurkat were used as a control (A, bottom panels). HPA were identified by GFAP staining, and DAPI staining was also performed to discern HPA from Nef.GFP-expressing Jurkat by the size of the nuclei (C). Nef transfer from Nef.GFP-expressing Jurkat to Jurkat (A), THP-1 (B) and HPA (C) was shown by arrows.