PROTECTION OF RABBITS AGAINST HTLV-II INFECTION WITH A SYNTHETIC PEPTIDE CORRESPONDING TO HTLV-II NEUTRALIZATION REGION

Rabbit immune sera raised against synthetic peptides of the HTLV-II en velope gp46 region were examined for HTLV-II neutralization ability by HTLV-vesicular stomatitis virus (VSV) pseudotype assay and syncytium inhibition assay. HTLV-II neutralization activity was detected in the sera against HTLV-II Env gp46, 80-103 but not in those to HTLV-II Env gp46, 171-196. Three rabbits immunized with the synthetic peptide of H TLV-II Env gp46, 80-103 and three non-immunized rabbits were challenge d with intravenous inoculation of an HTLV-II-producing human cell line (MOT, 1 x 10(7) cells). The non-immunized rabbits showed seroconversi on for HTLV-II after 2 weeks and maintained persistent infection but t he immunized rabbits were protected from HTLV-II infection. Nested or repeated polymerase chain reaction revealed the presence of HTLV-II pr ovirus sequences in the non-immunized rabbits but not in the immunized rabbits. These results suggest that peptide vaccination with a synthe tic peptide corresponding to the HTLV-II neutralization region is usef ul for preventing HTLV-II infection.