FIG. 1.

Detection of reverse-transcribed HTLV-1 RNA by PCR and effects of the HTLV-1 Env synthetic peptides on transmission of cell-free HTLV-1. (A) MOLT-4 cells were infected with serially diluted cell-free HTLV-1, lysed after incubation for 20 h, and examined by PCR amplification using the pXO 7302-7326 and pXO 7504-7481 primers (lanes 1 to 3). MOLT-4 cells were infected with cell-free HTLV-1 treated with HTLV-1-seronegative human serum (normal human serum [NHS]) or with HTLV-1-seropositive human serum (α-HTLV-1) for 1 h at 37°C. Lane 6, mock-infected control. PCR amplification was performed without template DNA (lane 7). (B) MOLT-4 cells were infected with HTLV-1 for 1 h in the presence of the Env gp46 or gp21 synthetic peptides at 10 μM. Amino acid positions of Env (the initiation codon of Met is 1) are shown above each lane. The amino acid sequences of the peptides are listed in Table 1. β-Globin DNA was amplified as a control to confirm the efficiency of the amplification of each sample.