Fine specificity of the B-cell epitopes recognized in HIV-1 NEF by human sera.
We have previously used partially overlapping synthetic nonapeptides to characterize the human natural antibody response against HIV-1 negative regulatory factor (NEF), and identified nine 5 to 13 amino acid long regions that were recognized by sera of HIV-1-infected individuals. In this report we define the minimal size of these epitopes with the use of shorter, from 3 to 8 amino acid long partially overlapping peptides covering the complete sequence of the previously identified reacting regions and the N- and C-terminal flanking sequences. We also introduce a new method for the analysis of the reactivities obtained with peptides of different lengths. In six of the antigenic regions the epitopes were found to be noncontiguous and to consist of multiple, down to three amino acid long separate reactive stretches (epitope 1: WSK, VGW, TVRERMRR; epitope 3A: PLRPM, SHFLK; epitope 3B: SQRRQD, DLW; epitope 3C: IYHT, QGYFPDWQN; epitope 4: SLL, VSL; epitope 5: EVLEWRFDSR, VAR). Three epitopes were clearly linear (epitope 2: CAWLE; epitope 3D: LTFGWC; epitope 6: PEYF). Interestingly, five of the minimized B-cell epitopes (1, 3A, 3C, 3D, 5) recognized by human sera overlap totally or partly with the previously identified T-cell epitopes in HIV-1 NEF. Also, only three of the epitopes (3C, 3D, 5) were in a computer-based homology search shown to contain strictly NEF-specific sequences.
University of Tampere, Institute of Biomedical Sciences, Finland.
M
M
Tähtinen
F
F
Gombert
E R
ER
Hyytinen
G
G
Jung
A
A
Ranki
K J
KJ
Krohn
D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D015693:Gene Products, nef / Q000276:immunology*; D014644:Genetic Variation; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D054311:nef Gene Products, Human Immunodeficiency Virus
D000939:Epitopes; D015693:Gene Products, nef; D010446:Peptide Fragments; D054311:nef Gene Products, Human Immunodeficiency Virus