AIDS. 1992 Dec;6(12):1451-6. Unique Identifier : AIDSLINE MED/93152028
OBJECTIVE: To map epitopes on gp120 defined by human antibodies and to
examine the neutralizing activity of these antibodies. DESIGN AND
METHODS: Serum from HIV-1-antibody-positive individuals was used to
screen a random fragment expression library representing gp120 from the
HIVIIIB clone BH10. The library was based on the pUEX1 expression
vector. Serum was tested for in vitro neutralizing activity using H9
cells and the HIVIIIB isolate. RESULTS: Four different epitopes defined
by human antibodies were mapped on gp120. Two of these have not
previously been reported and are located within amino acids (aa) 90-100
in the C1 region and aa 355-365 in the semi-conserved region between V3
and V4. The other two are located within aa 140-145 and aa 286-309.
These epitopes are situated in regions that have been shown to demarcate
human epitopes. Three serum samples with neutralization titres > or =
1024 were identified. None of the purified antibody fractions defining
the mapped epitopes on gp120 had any neutralizing capacity against
HIVIIIB. CONCLUSIONS: This study is the first demonstration of the
applicability of random fragment expression libraries for the direct
screening of human serum in order to map epitopes on gp120. Two new
epitopes and two previously identified epitopes were mapped in this way.
However, none of the linear epitopes was defined by antibody fractions
neutralizing HIVIIIB, and it was not possible to map epitopes defined by
neutralizing antibodies in the serum samples capable of neutralizing
HIVIIIB infection of H9 cells. Thus, it appears that the neutralizing
activity of serum in this study was not due to anti-gp120 antibodies
defining linear epitopes.
Amino Acid Sequence B-Lymphocytes/*IMMUNOLOGY Base Sequence
Enzyme-Linked Immunosorbent Assay Epitopes/GENETICS/*IMMUNOLOGY Gene
Library Human HIV Antibodies/*IMMUNOLOGY HIV Envelope Protein
gp120/GENETICS/*IMMUNOLOGY HIV-1/*IMMUNOLOGY Molecular Sequence Data
Neutralization Tests Peptide Fragments/IMMUNOLOGY Support, Non-U.S.
Gov't JOURNAL ARTICLE