To fully define cytotoxic T-lymphocyte (CTL) escape variants of an HLA-B*51-restricted integrase epitope in early HIV-1 infection.
Ninety-four longitudinally sampled acute/early HIV-1 subtype B-infected participants were assessed to determine HLA-B*51-restricted LPPVVAKEI (LI9) escape variants.
LI9 was sequenced at baseline and subsequent time points. Interferon-γ (IFNγ) ELISpot assays were performed using serial log dilutions of variant LI9 peptides to determine the cellular response and functional avidity.
There is a significant association between HLA-B*51 expression and an evolving LI9 sequence from baseline to year 1 (P < 0.0001). We detected that the V32I and P30X polymorphisms emerged within HLA-B*51+ participants over time. Reversion of the P30S polymorphism was observed by year 1 in one HLA-B*51− participant. LPPIIAKEI and LPSIVAKEI had significantly lower functional avidity compared with LPPVVAKEI and so may be less well recognized by LI9-specific CTLs; a positive IFNγ response to IPSVVAKEI was rarely seen. Functional avidity to wild-type LI9 inversely correlated with viral load (R2 = 0.448, P = 0.0485).
Our results provide support for the role of HLA-B*51-restricted CTLs and functional avidity in the control of early HIV-1 infection.
aNuffield Department of Clinical Medicine, Peter Medawar Building for Pathogen Research, University of Oxford
bThe James Martin 21st Century School, Peter Medawar Building for Pathogen Research
cOxford NIHR Biomedical Research Centre, Oxford
dDepartment of Medicine, Imperial College, London, UK.
Correspondence to Nicole Yager, Nuffield Department of Clinical Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford OX1 3SY, UK. E-mail: firstname.lastname@example.org
Received 3 May, 2012
Revised 7 October, 2012
Accepted 16 October, 2012