Assessment of HTLV-1 infection in inoculated rabbits. Rabbits were inoculated with approximately 1 × 10⁷ irradiated 729HTLV-1, 729HTLV-1ΔPBM-infected cells, or uninfected control cells. At weeks 0, 2, 4, 6, and 8 after inoculation, rabbit PBMCs and sera were isolated from blood. HTLV-1–specific serologic response. Sera from inoculated rabbits were tested for reactivity to specific HTLV-1 proteins by Western blot. A representative rabbit from the positive wtHTLV-1–inoculated group (R1-R5) and negative control group (R18-R22), and 3 HTLV-1ΔPBM–inoculated rabbits (R40-R42) are shown. Viral proteins and 729 cell–specific proteins (^**) are labeled on the left.