Characterization of immunodominant epitopes of gag and pol gene-encoded proteins of human T-cell lymphotropic virus type I.
A series of synthetic peptides derived from the corresponding regions of the gag, pol, and env proteins of human T-cell lymphotropic virus types I (HTLV-I) and II (HTLV-II) were used in an enzyme immunoassay to map the immunodominant epitopes of HTLV. Serum specimens from 79 of 87 (91%) HTLV-I-infected patients reacted with the synthetic peptide Gag-1a (amino acids [a.a.] 102 to 117) derived from the C terminus of the p19gag protein of HTLV-I. Minimal cross-reactivity (11%) was observed with serum specimens from HTLV-II-infected patients. Peptide Pol-3, encoded by the pol region of HTLV-I (a.a. 487 to 502), reacted with serum specimens from both HTLV-I- and HTLV-II-infected patients (94 and 86%, respectively). The antibody levels to Pol-3 were significantly higher (P less than 0.01) in patients with HTLV-I-associated myelopathy/tropical spastic paraparesis than in either adult T-cell leukemia patients or HTLV-I-positive asymptomatic carriers. None of the other peptides studied demonstrated significant binding to serum specimens obtained from HTLV-I- or HTLV-II-infected individuals. While Gag-1a did not react with serum specimens from normal controls, Pol-3 demonstrated some reaction with specimens from seronegative individuals (11.4%). The antibodies to Gag-1a and Pol-3 in serum specimens from HTLV-I-infected patients could be specifically inhibited by the corresponding synthetic peptides and by a crude HTLV-I antigen preparation, indicating that these peptides mimic native epitopes present in HTLV-I proteins that are recognized by serum antibodies from HTLV-I- and -II-infected individuals.
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Retrovirus Diseases Branch, Centers for Disease Control, Atlanta, Georgia 30333.
Rudolph
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Griffis
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Kitamura
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K
Honda
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Coligan
J E
JE
Folks
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TM
D000595:Amino Acid Sequence; D001667:Binding, Competitive; D015686:Gene Products, env / Q000096:biosynthesis / Q000235:genetics; D015683:Gene Products, gag / Q000096:biosynthesis / Q000235:genetics*; D015684:Gene Products, pol / Q000096:biosynthesis / Q000235:genetics*; D015481:HTLV-I Antibodies / Q000096:biosynthesis*; D015490:HTLV-I Infections / Q000150:complications / Q000276:immunology; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000276:immunology; D006801:Humans; D016056:Immunodominant Epitopes / Q000235:genetics*; D007074:Immunoglobulin G / Q000276:immunology; D008969:Molecular Sequence Data; D015493:Paraparesis, Tropical Spastic / Q000150:complications / Q000276:immunology; D011487:Protein Conformation
D015686:Gene Products, env; D015683:Gene Products, gag; D015684:Gene Products, pol; D015481:HTLV-I Antibodies; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G