Distinct localizations of the TCR and HTLV Env receptor in activated CD4⁺ lymphocytes.

(A) Unstimulated or αCD3/αCD28-stimulated CD4⁺lymphocytes were incubated with an αCD4 mAb, detected with a goat antimouse IgG-Cy3, and the HTLV Env SU RBD fused to EGFP (H_RBD-EGFP). Cells were examined by confocal immunofluorescence microscopy. (B) Capping was induced in prestimulated CD4⁺ lymphocytes using an αCD3 mAb. After a 30-minute induction at room temperature, cells were fixed and incubated with a goat αmouse IgG-Cy3 and H_RBD-EGFP to visualize the localization of CD3 and the HTLV receptor, respectively. Original magnification, × 100.