The conserved carboxy terminal region of HIV-1 gp120 is recognized by seronegative HIV-exposed people.
OBJECTIVE
To screen HIV-positive, long-term exposed seronegative and low-risk individuals for the presence of antibodies against regions of HIV-1 gp120 that share some degree of homology with HLA.


METHODS
Sera were obtained from 63 HIV-1-infected subjects [52 Centers for Disease Control and Prevention (CDC) stage 2 and 11 stages 3/4], 32 HIV-exposed uninfected (HEU) subjects and from 24 low-risk HIV-1 seronegative individuals. They were tested by a peptide-based enzyme-linked immunosorbent assay (ELISA) for reactivity against peptides derived from the HIV-1 gp120 C-terminal region that contain regions of MHC sequence/structural similarity. Ten randomly selected sera from each group were also screened for anti-class I antibodies.


RESULTS
Thirty per cent of the long-term HIV-1-exposed seronegative individuals had antibodies against the conserved C-terminal region (C5) of HIV-1 gp120. However, sera from HEU individuals showed no reactivity against other peptides derived from the C2 region of gp120, also an HLA homologous region. Anti-C terminal gp120 antibodies were mainly of IgM subclass, although IgG-specific antibodies were also present. In addition, 70% of HEU individuals had antibodies to HLA class I molecules compared with 15% of HIV-positive patients (restricted to only those HIV-positive patients with anti C-terminal antibodies).


CONCLUSIONS
Our results suggest that antibody responses against the C-terminal region of HIV gp120 and HLA class I may represent markers of apparent natural protection against HIV-1 infection.
Brown
L
L
Oncology Department, St George's Hospital Medical School, London, UK.
Souberbielle
B E
BE
Marriott
J B
JB
Westby
M
M
Desselberger
U
U
Kaye
T
T
Gougeon
M L
ML
Dalgleish
A
A
D015492:AIDS Serodiagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D020276:HIV Long-Term Survivors; D018023:HIV Seronegativity; D015497:HIV-1 / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D010446:Peptide Fragments / Q000276:immunology*
D000939:Epitopes; D015699:HIV Envelope Protein gp120; D006680:HLA Antigens; D007075:Immunoglobulin M; D010446:Peptide Fragments