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NLM AIDSLINE

Mapping of two new human B-cell epitopes on HIV-1 gp120.




 

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



 




Information in this article was accurate in May 30, 1993. The state of the art may have changed since the publication date. This material is designed to support, not replace, the relationship that exists between you and your doctor. Always discuss treatment options with a doctor who specializes in treating HIV.