title: Identification of a novel neutralization epitope on envelope gp46 antigen of human T-cell-leukemia virus-type-II (HTLV-II).
abstract: Having observed that multiple neutralization epitopes of human T-cell-leukemia-virus-type-I (HTLV-I) envelope gp46 clustered in a region between amino acids 187 and 199, we speculated that a region of HTLV-II gp46 corresponding to the HTLV-I-neutralization region may contain HTLV-II-specific neutralization epitopes. To test this, we immunized a NZW rabbit and BALB/c mice with a synthetic peptide containing the HTLV-II gp46 amino acids 182 to 199 (pep182-199) conjugated to OVA. The serum from the rabbit reacted to the HTLV-II gp46 and neutralized HTLV-II-mediated syncytium formation. One monoclonal antibody (MAb), M2E186N1, generated from the BALB/c mice, stained specifically the surface of HTLV-II-positive cells and reacted with HTLV-II gp46 by Western blot. This MAb was of the IgA isotype and inhibited HTLV-II- but not HTLV-I-mediated syncytium formation at a final antibody concentration of 200 micrograms/ml; it also neutralized an HTLV-II-VSV pseudotype virus specifically. Epitope mapping by ELISA using overlapping synthetic peptides indicated that the neutralization epitope recognized by the M2E186N1 MAb was located between HTLV-II gp46 amino acids 186 and 192, corresponding to the sequence Leu-Gln-His-Val-Ile-Leu-Gln-Pro. These new observations will be helpful in developing vaccines against HTLV-II infection.
authors.affiliation: Department of Biosciences, School of Science, Kitasato University, Sagamihara, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: R
authors.initials: R
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Hoshino
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D015686:Gene Products, env / Q000737:chemistry / Q000276:immunology*; D015487:HTLV-II Antigens / Q000032:analysis*; D015367:Human T-lymphotropic virus 2 / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011817:Rabbits; D015682:Retroviridae Proteins, Oncogenic / Q000737:chemistry / Q000276:immunology*; D054299:env Gene Products, Human Immunodeficiency Virus
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D015686:Gene Products, env; D015487:HTLV-II Antigens; D007070:Immunoglobulin A; D015682:Retroviridae Proteins, Oncogenic; D054299:env Gene Products, Human Immunodeficiency Virus; C069568:gp46 protein, Human immunodeficiency virus 2