Bioinformatic and empirical analysis of novel hypoxia-inducible targets of the human antituberculosis T cell response

J Immunol. 2012 Dec 15;189(12):5867-76. doi: 10.4049/jimmunol.1202281. Epub 2012 Nov 19.

Abstract

We analyzed whole genome-based transcriptional profiles of Mycobacterium tuberculosis subjected to prolonged hypoxia to guide the discovery of novel potential Ags, by a combined bioinformatic and empirical approach. We analyzed the fold induction of the 100 most highly induced genes at 7 d of hypoxia, as well as transcript abundance, peptide-binding prediction (ProPred) adjusted for population-specific MHC class II allele frequency, and by literature search. Twenty-six candidate genes were selected by this bioinformatic approach and evaluated empirically using IFN-γ and IL-2 ELISPOT using immunodominant Ags (Acr-1, CFP-10, ESAT-6) as references. Twenty-three of twenty-six proteins induced an IFN-γ response in PBMCs of persons with active or latent tuberculosis. Five novel immunodominant proteins-Rv1957, Rv1954c, Rv1955, Rv2022c, and Rv1471-were identified that induced responses similar to CFP-10 and ESAT-6 in both magnitude and frequency. IL-2 responses were of lower magnitude than were those of IFN-γ. Only moderate evidence of infection stage-specific recognition of Ags was observed. Reconciliation of bioinformatic and empirical hierarchies of immunodominance revealed that Ags could be predicted, providing transcriptomic data were combined with peptide-binding prediction adjusted by population-specific MHC class II allele frequency.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Computational Biology / methods*
  • Gene Targeting
  • Genome, Bacterial / genetics
  • Genome, Bacterial / immunology
  • Humans
  • Hypoxia / genetics*
  • Hypoxia / immunology*
  • Hypoxia / microbiology
  • Middle Aged
  • Mycobacterium tuberculosis / genetics*
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / immunology*
  • Predictive Value of Tests
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism
  • T-Lymphocyte Subsets / microbiology*
  • Tuberculosis, Pulmonary / immunology
  • Tuberculosis, Pulmonary / microbiology
  • Tuberculosis, Pulmonary / prevention & control*
  • Young Adult