CD8+ T lymphocyte responses target functionally important regions of Protease and Integrase in HIV-1 infected subjects

Journal of Translational Medicine. 2004;2(1):15 DOI 10.1186/1479-5876-2-15

 

Journal Homepage

Journal Title: Journal of Translational Medicine

ISSN: 1479-5876 (Online)

Publisher: BMC

LCC Subject Category: Medicine

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML

 

AUTHORS

Yu Xu G
Fitzpatrick Cecily A
Rathod Almas
Addo Marylyn M
Rodriguez William R
Perkins Beth
Rosenberg Eric S
Altfeld Marcus
Walker Bruce D

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 25 weeks

 

Abstract | Full Text

<p>Abstract</p> <p>Background</p> <p>CD8+ T cell responses are known to be important to the control of HIV-1 infection. While responses to reverse transcriptase and most structural and accessory proteins have been extensively studied, CD8 T cell responses specifically directed to the HIV-1 enzymes Protease and Integrase have not been well characterized, and few epitopes have been described in detail.</p> <p>Methods</p> <p>We assessed comprehensively the CD8 T cell responses to synthetic peptides spanning Protease and Integrase in 56 HIV-1 infected subjects with acute, chronic, or controlled infection using IFN-γ-Elispot assays and intracellular cytokine staining. Fine-characterization of novel CTL epitopes was performed on peptide-specific CTL lines in Elispot and <sup>51</sup>Chromium-release assays.</p> <p>Results</p> <p>Thirteen (23%) and 38 (68%) of the 56 subjects had detectable responses to Protease and Integrase, respectively, and together these targeted most regions within both proteins. Sequence variability analysis confirmed that responses cluster largely around conserved regions of Integrase, but responses against a large, highly conserved region of the N-terminal DNA-binding domain of Integrase were not readily detected. CD8 T cell responses targeted regions of Protease that contain known Protease inhibitor mutation residues, but strong Protease-specific CD8 T cell responses were rare. Fine-mapping of targeted epitopes allowed the identification of three novel, HLA class I-restricted, frequently-targeted optimal epitopes. There were no significant correlations between CD8 T cell responses to Protease and Integrase and clinical disease category in the study subjects, nor was there a correlation with viral load.</p> <p>Conclusions</p> <p>These findings confirm that CD8 T cell responses directed against HIV-1 include potentially important functional regions of Protease and Integrase, and that pharmacologic targeting of these enzymes will place them under both drug and immune selection pressure.</p>