Antigenic variation of the dominant gp41 epitope in Africa.
OBJECTIVE
To determine the value of (combinations of) synthetic peptides representing immunodominant sites on HIV-1/HIV-2 transmembrane proteins for the detection and discrimination between HIV-1 and HIV-2 infection in various populations.


METHODS
Two 24-mer synthetic peptides derived from immunodominant sites on the HIV-1 and HIV-2 transmembrane proteins were used separately, in combination (env 1/2), and in combination with recombinant p24 (p24/env) in enzyme-linked immunosorbent assays.


RESULTS
Positive reactions with env-1 were found in 150 out of 150 (100%) samples from Dutch AIDS patients, 60 out of 60 (100%) samples from Dutch homosexual men obtained 1 year after HIV-1-antibody seroconversion, 29 out of 30 (96.7%) samples from these men obtained at the time of HIV-1-antibody seroconversion, 40 out of 41 (97.6%) samples from East Africans with AIDS-related symptoms, and three out of 29 (10.3%) samples from West Africans with HIV-2 infection (including a sample from an individual infected with both HIV-1 and HIV-2). Positive reactions with env-2 in these study populations were 11 out of 150 (7.3%), nine out of 60 (15%), none out of 30 (0%), 25 out of 41 (60.9%) and 29 out of 29 (100%), respectively. In the samples with dual reactivity, true versus cross-reactivity could generally be differentiated on the basis of large differences in optical density values in the respective assays. All samples reacted positively with p24/env; 308 out of 310 (99.3%) were positive in the env 1/2 assay. Four East African samples that had negative or only weakly positive reactions with env-1 showed a noticeably stronger reaction with variant peptides derived from Central African isolate sequences. In all samples from HIV-1-infected Dutch homosexual men, the strongest signal was detected using the env-1 peptide sequence, which is derived from European and American isolates.


CONCLUSIONS
Small peptide antigens may permit the detection of strain-specific antibodies, allowing serological characterization of HIV isolates.
Department of Virology, University of Amsterdam, The Netherlands.
J M
JM
Lange
V J
VJ
Teeuwsen
C A
CA
Boucher
A
A
Vahlne
F
F
Barin
S
S
Tjong-A-Hung
J
J
Dekker
U
U
Parkhede
F
F
de Wolf
J
J
Goudsmit
D000349:Africa; D000595:Amino Acid Sequence; D000940:Antigenic Variation; D015700:HIV Envelope Protein gp41 / Q000235:genetics*; D015658:HIV Infections / Q000382:microbiology; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D015498:HIV-2 / Q000235:genetics / Q000276:immunology; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000235:genetics / Q000276:immunology
D015700:HIV Envelope Protein gp41; D010455:Peptides