Caveolin-1 is consistently expressed in HTLV-1–infected T-cell lines and primary ATL cells. (A) Expression of caveolin-1, caveolin-2, Tax, and HBZ in HTLV-1–infected T-cell lines. RT-PCR analysis was carried out for caveolin-1, caveolin-2, Tax, HBZ, and β-actin (loading control). Western blot analysis was performed for caveolin-1, Tax, and actin. The dotted line indicates the grouping of images from different parts of the same gel. Representative results of 3 separate experiments with similar results. (B) RT-PCR analysis for expression of caveolin-1 and caveolin-2 in normal PBMCs and primary ATL cells. Normal PBMCs from healthy donors (n = 2) and freshly isolated primary ATL cells (> 90% leukemic cells) from patients (n = 9) were examined as indicated. Representative results of 3 separate experiments with similar findings. (C) Expression of caveolin-1 and IL-2Rα in PHA-stimulated or unstimulated PBMCs. Normal PBMCs were treated with PHA for 3 days (PHA-PBMC). Representative results of 3 separate experiments with similar findings. (D) Immunohistochemical staining of caveolin-1 in ATL lymph node and skin lesions. Tissue sections from ATL lymph nodes (n = 6) and skin lesions (n = 10) were stained with anti–caveolin-1 antibody. Tissue sections were counterstained with methyl green. Representative results from a single donor. Original magnification, ×400. Cav indicates caveolin.