Serological detection of attenuated HIV-1 variants with nef gene deletions.
OBJECTIVE
To investigate whether members of a transfusion-linked cohort (the Sydney Bloodbank Cohort) infected with a nef-deleted strain of HIV-1 could be differentiated from individuals infected with wild-type strains of HIV-1 by characterizing the Nef antibody response of cohort members.


METHODS
Retrospective and prospective analysis of the nef gene sequence and the antibody response to Nef peptides in HIV-infected subjects.


METHODS
Plasma was obtained from all individuals of the Sydney cohort, and from a variety of HIV-1-infected and uninfected controls. Antibodies recognizing full-length recombinant HIV-1NL43 Nef protein and synthetic peptide analogues were assessed by enzyme-linked immunosorbent assay.


RESULTS
All 34 individuals infected with wild-type HIV-1 had antibodies reacting with full-length Nef protein as well as with a series of synthetic peptides (6-23-mers) spanning most of the Nef protein of HIV-1NL43. Although the HIV-1 quasispecies infecting the Sydney cohort had a consensus deletion of the nef gene corresponding to amino-acids 165-206, HIV-1 strains from individual members of the cohort had additional deletions comprising up to 80% of the nef gene. Members of the cohort had antibodies to peptides homologous to all regions of the Nef protein tested, except for a single peptide (amino-acids 162-177) that lies within the consensus nef deletion for the cohort quasispecies.


CONCLUSIONS
These data show that nef-deleted strains of HIV-1 can be detected serologically. In the Sydney cohort, detection of antibodies to all regions of Nef tested, except that corresponding to amino-acids 162-177, suggests that observed deletions outside this domain occurred after this virus had infected these subjects and stimulated an immune response. A Nef peptide serological assay may be useful for identifying further examples of individuals infected with nef-deleted, attenuated HIV-1 quasispecies and for assessing the evolution of those variants in vivo.
Greenway
A L
AL
AIDS Cellular Biology Unit, National Centre in HIV Virology Research, Macfarlane Burnet Centre for Medical Research, Fairfield, Victoria, Australia.
Mills
J
J
Rhodes
D
D
Deacon
N J
NJ
McPhee
D A
DA
D015492:AIDS Serodiagnosis / Q000379:methods*; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D018604:Epitope Mapping; D019143:Evolution, Molecular; D015693:Gene Products, nef; D015754:Genes, nef / Q000235:genetics*; D015483:HIV Antibodies / Q000097:blood*; D006679:HIV Seropositivity / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D010455:Peptides / Q000138:chemical synthesis; D011446:Prospective Studies; D011994:Recombinant Proteins; D012189:Retrospective Studies; D017384:Sequence Deletion / Q000235:genetics / Q000276:immunology*; D017741:Survivors; D014739:Victoria; D054311:nef Gene Products, Human Immunodeficiency Virus
D015693:Gene Products, nef; D015483:HIV Antibodies; D010455:Peptides; D011994:Recombinant Proteins; D054311:nef Gene Products, Human Immunodeficiency Virus