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Conformational Evaluation of HIV-1 Trimeric Envelope Glycoproteins Using a Cell-based ELISA Assay
Published on: September 14, 2014
Precise identification of a human immunodeficiency virus type 1 antigen processing mutant
Peter Zimbwa1, Anita Milicic, John Frater
1The James Martin 21st Century School at The Peter Medawar Building for Pathogen Research, Nuffield Department of Clinical Medicine, University of Oxford, South Parks Road, Oxford OX1 3SY, United Kingdom.
Journal of Virology
|November 17, 2006
Summary
Human immunodeficiency virus type 1 (HIV-1) immune escape is complex. A specific HIV-1 reverse transcriptase (RT) polymorphism (E169D) prevents cytotoxic T cell recognition of key epitopes by altering antigen processing.
Area of Science:
- Immunology
- Virology
- Molecular Biology
Background:
- Human immunodeficiency virus type 1 (HIV-1) triggers a robust immune response, yet viral persistence occurs.
- Viral evolution involves polymorphisms in antigenic sites, leading to immune recognition loss and positive selection.
- Amino acid variations outside known epitopes can facilitate immune escape by disrupting optimal peptide antigen processing.
Purpose of the Study:
- To investigate the immune escape mechanism of the E169D polymorphism in HIV-1 reverse transcriptase (RT) associated with HLA-B*0702.
- To determine if the E169D polymorphism interferes with the generation and recognition of the HLA-B*0702-restricted SM9 epitope.
- To explore the impact of E169D on other HLA-restricted epitopes, specifically an HLA-A*03-restricted epitope.
Main Methods:
- Analysis of the association between HIV-1 E169D polymorphism and HLA-B*0702.
- Investigation of cytotoxic T cell recognition of the SM9 epitope in the presence of the E169D polymorphism.
- Assessment of aberrant proteasomal cleavage affecting epitope generation.
- Evaluation of E169D's effect on an HLA-A*03-restricted epitope (MR9).
Main Results:
- The E169D polymorphism in HIV-1 RT is significantly associated with HLA-B*0702.
- E169D prevents immune recognition of the SM9 epitope by cytotoxic T cells due to impaired epitope generation via aberrant proteasomal cleavage.
- The E169D polymorphism also disrupts recognition of the HLA-A*03-restricted MR9 epitope.
Conclusions:
- Single amino acid variations outside known epitopes can mediate viral immune escape by affecting antigen processing.
- Statistical associations between viral polymorphisms and HLA types can indicate potential immune escape mechanisms.
- Interpreting the immunological consequences of HIV sequence variations requires understanding complex epitope generation and processing pathways.
