Motozono, Chihiro, Miles, John J., Hasan, Zafrul, Gatanaga, Hiroyuki, Meribe, Stanley C., Price, David A., Oka, Shinichi, Sewell, Andrew K., and Ueno, Takamasa (2013) CD8⁺ T cell cross-reactivity profiles and HIV-1 immune escape towards an HLA-B35-restricted immunodominant Nef epitope. PLoS ONE, 8 (6). e66152. pp. 1-6.

Preview

PDF (Published Version) - Published Version Available under License Creative Commons Attribution. Download (423kB) | Preview

 

6

999

Abstract

Antigen cross-reactivity is an inbuilt feature of the T cell compartment. However, little is known about the flexibility of T cell recognition in the context of genetically variable pathogens such as HIV-1. In this study, we used a combinatorial library containing 24 billion octamer peptides to characterize the cross-reactivity profiles of CD8⁺ T cells specific for the immunodominant HIV-1 subtype B Nef epitope VY8 (VPLRPMTY) presented by HLA-B*35∶01. In conjunction, we examined naturally occurring antigenic variations within the VY8 epitope. Sequence analysis of plasma viral RNA isolated from 336 HIV-1-infected individuals revealed variability at position (P) 3 and P8 of VY8; Phe at P8, but not Val at P3, was identified as an HLA-B*35∶01-associated polymorphism. VY8-specific T cells generated from several different HIV-1-infected patients showed unique and clonotype-dependent cross-reactivity footprints. Nonetheless, all T cells recognized both the index Leu and mutant Val at P3 equally well. In contrast, competitive titration assays revealed that the Tyr to Phe substitution at P8 reduced T cell recognition by 50–130 fold despite intact peptide binding to HLA-B*35∶01. These findings explain the preferential selection of Phe at the C-terminus of VY8 in HLA-B*35∶01⁺ individuals and demonstrate that HIV-1 can exploit the limitations of T cell recognition in vivo.

Actions (Repository Staff Only)

Item Control Page