Integrating in silico and in vitro analysis of peptide binding affinity to HLA-Cw*0102: a bioinformatic approach to the prediction of new epitopes

PLoS One. 2009 Nov 30;4(11):e8095. doi: 10.1371/journal.pone.0008095.

Abstract

Background: Predictive models of peptide-Major Histocompatibility Complex (MHC) binding affinity are important components of modern computational immunovaccinology. Here, we describe the development and deployment of a reliable peptide-binding prediction method for a previously poorly-characterized human MHC class I allele, HLA-Cw*0102.

Methodology/findings: Using an in-house, flow cytometry-based MHC stabilization assay we generated novel peptide binding data, from which we derived a precise two-dimensional quantitative structure-activity relationship (2D-QSAR) binding model. This allowed us to explore the peptide specificity of HLA-Cw*0102 molecule in detail. We used this model to design peptides optimized for HLA-Cw*0102-binding. Experimental analysis showed these peptides to have high binding affinities for the HLA-Cw*0102 molecule. As a functional validation of our approach, we also predicted HLA-Cw*0102-binding peptides within the HIV-1 genome, identifying a set of potent binding peptides. The most affine of these binding peptides was subsequently determined to be an epitope recognized in a subset of HLA-Cw*0102-positive individuals chronically infected with HIV-1.

Conclusions/significance: A functionally-validated in silico-in vitro approach to the reliable and efficient prediction of peptide binding to a previously uncharacterized human MHC allele HLA-Cw*0102 was developed. This technique is generally applicable to all T cell epitope identification problems in immunology and vaccinology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Motifs
  • Computational Biology / methods*
  • Edetic Acid / chemistry
  • Epitopes / chemistry*
  • HIV-1 / metabolism
  • HLA-C Antigens / chemistry*
  • Histocompatibility Antigens Class I / chemistry
  • Humans
  • In Vitro Techniques
  • Leukocytes, Mononuclear / metabolism
  • Major Histocompatibility Complex
  • Models, Statistical
  • Peptides / chemistry*
  • Protein Binding
  • Protein Structure, Tertiary

Substances

  • Epitopes
  • HLA-C Antigens
  • HLA-C*01:02 antigen
  • Histocompatibility Antigens Class I
  • Peptides
  • Edetic Acid