Glycosylation-dependent peptide antigenic determinants of env gp46 HTLV-1.
Human T-lymphotropic virus type 1 (HTLV-I) is a retrovirus associated with adult T-cell leukemia/lymphoma, and the virus infection constitutes a growing public health problem. In a continuing effort to engineer conformationally dependent HTLV-I epitopes that elicit a protective immune response, we have examined the role and functional importance of carbohydrate moieties in specific immune recognition and antibody responses. There have been several reports of the importance of N-linked virus glycosylation in the formation of neutralizing antibodies. Residues 230-257 is predicted to encode two beta-turn/loop regions at 240-244 (LYGPN), 248-257 (VPSSSSTPL) and a glycosylation site at N-244 (NVS). We have successfully engineered and synthesized the 233-253 sequence of gp46 of HTLV-1 with and without GlcNAC at Asn244. Circular dichroism spectroscopy and proton NMR showed the presence of beta-turn conformation in both peptide constructs. Chimeras of the glycosylated and non-glycosylated epitope with promiscuous T-cell epitope were synthesized and shown to elicit high titered antibodies in rabbits specific for the immunogen (SC1MVF and SC2MVF) and the B cell epitope 233-253. Additionally, antibodies to the glycosylated form of the peptide recognized the HTLV-I envelope precursor in radioimmunoassay precipitation assay and react with HTLV-I whole virus preparations in ELISA.
D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D000917:Antibody Formation; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis* / Q000737:chemistry; D015686:Gene Products, env / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology*; D015752:Genes, env; D006020:Glycopeptides / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification; D006031:Glycosylation; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D015458:Leukemia, T-Cell / Q000276:immunology*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification; D011817:Rabbits / Q000276:immunology; D015682:Retroviridae Proteins, Oncogenic / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology*
D000906:Antibodies; D000939:Epitopes; D015686:Gene Products, env; D006020:Glycopeptides; D010446:Peptide Fragments; D015682:Retroviridae Proteins, Oncogenic; C055266:gp46 protein, Human T-cell leukemia virus type I