Zuguang Wang | PubMed Health

PubMed2005

Predefined spacers between epitopes on a recombinant epitope-peptide impacted epitope-specific antibody response.

We have developed a widely applicable method to construct epitope-peptide gene for epitope-vaccine strategy recently. In this study, we wanted to know whether the predefined spacers between epitopes on a recombinant epitope-peptide impacted the production of epitope-specific antibodies. The neutralizing epitope ELDKWA on the C-domain of HIV-1 gp41 was defined by the monoclonal antibody (mAb) 2F5 with broad neutralizing activity. We constructed three recombinant ELDKWA-epitope-peptides with different spacers between epitopes. The recombinant epitope-peptide GST-K8, GST-S8 and GST-R8 were bearing eight copies of ELDKWA-epitope with amino acid spacer GS, GSGGGGS and RS, respectively. GST-K8 and GST-S8 could induce high titer of ELDKWA-epitope-specific antibodies, much better than GST-R8. Besides, both antibodies could recognize the recombinant soluble gp41 and the transfected CHO-WT cells that stably express HIV-1 envelope glycoprotein on the cell surfaces. These experimental results indicated that the spacer GSGGGGS and GS were feasible in constructing a recombinant epitope-vaccine.

Animals↗

PubMed2005

The recombinant immunogen with high-density epitopes of ELDKWA and ELDEWA induced antibodies recognizing both epitopes on HIV-1 gp41.

The high mutation rate of HIV-1 (human immunodeficiency virus-1) is a major obstacle to developing an effective vaccine. The mutation of ELDKWA-(aa669-674) to ELDEWA-epitope on HIV-1 gp41 caused the immune escape from neutralization by potent anti-HIV-1 human monoclonal antibody (mAb) 2F5. In this study, we suggested and evaluated a multi-epitope vaccine as a new strategy to develop HIV-1 vaccines. A glutathione S-transferase (GST) fusion protein (GST-K8E8) containing 8 copies of ELDKWA-and mutated ELDEWA-epitopes was constructed and used to immunize mice or rabbits. Analysis of the antisera (rAS3) induced by GST-K8E8 suggested that multi-epitope vaccine immunogen could raise antibodies in mice and rabbits against either the original ELDKWA-epitope or the mutated ELDEWA-epitope that resulted in immune escape. Briefly, ELDKWA-epitope-specific antibodies, directly purified from rAS3 by ELDKWA-epitope-peptide affinity chromatography, recognized either original gp41 protein (ELDKWA, rgp41K) or mutated gp41 (ELDEWA, rgp41E) in immunoblotting assay; in contrast, the existing ELDKWA-epitope antibodies recognized only rgp41K but not rgp41E, which were purified by ELDKWA-epitope-peptide affinity chromatography from rAS3 that were firstly completely pre-absorbed by ELDEWA-epitope-peptide affinity beads. And the same results were also observed when detecting the ELDEWA-epitope-specific antibodies in rAS3 by a means similar to the above. All the data presented here demonstrated that a high density multi-epitope vaccine could be an interesting strategy against HIV-1 mutation.

Animals↗