RT Journal Article SR Electronic T1 C-terminal region of human T cell lymphotropic virus type I (HTLVI) p19 core protein is immunogenic in humans and contains an HTLVI-specific epitope. JF The Journal of Immunology JO J. Immunol. FD American Association of Immunologists SP 2393 OP 2397 VO 136 IS 7 A1 Palker, T J A1 Scearce, R M A1 Copeland, T D A1 Oroszlan, S A1 Haynes, B F YR 1986 UL http://www.jimmunol.org/content/136/7/2393.abstract AB To study the human host response to viral structural proteins during HTLV type I infection, five synthetic peptides matching the N-terminal and C-terminal regions of HTLVI p19 core protein were used to identify antigenic sites on p19 that were immunogenic in man. In radioimmunoassay and immunoprecipitation experiments, antibodies in 16 of 18 HTLVI+ patient sera reacted with a synthetic peptide matching the C-terminal 11-amino acid sequence of p19, whereas only two sera contained antibodies that reacted with other N- or C-terminal region p19 synthetic peptides. Polyclonal rabbit antisera to N- and C-terminal peptides reacted with a native viral protein of 19,000 daltons and with gag-encoded precursors of p19. Six monoclonal antibodies against native viral p19 were screened for reactivity to the five synthetic peptides. One of six antibodies (13B12) reacted with the C-terminal synthetic peptide of p19. Antibody 13B12 did not react with HTLVII or HTLVIII proteins or with HTLVIII-infected cells, nor did it cross-react with a wide variety of HTLV-uninfected normal host tissues. Thus, the C-terminus of p19 contains an antigen that is highly immunogenic in most HTLVI-infected patients and is HTLVI specific.