Mutational escape in HIV-1 CTL epitopes leads to increased binding to inhibitory myelomonocytic MHC class I receptors

PLoS One. 2010 Dec 8;5(12):e15084. doi: 10.1371/journal.pone.0015084.

Abstract

Escape mutations in HIV-1 cytotoxic T cell (CTL) epitopes can abrogate recognition by the TCR of HIV-1-specific CD8+ T cells, but may also change interactions with alternative MHC class I receptors. Here, we show that mutational escape in three HLA-A11-, B8- and B7- restricted immunodominant HIV-1 CTL epitopes consistently enhances binding of the respective peptide/MHC class I complex to Immunoglobulin-like transcript 4 (ILT4), an inhibitory myelomonocytic MHC class I receptor expressed on monocytes and dendritic cells. In contrast, mutational escape in an alternative immunodominant HLA-B57-restricted CTL epitope did not affect ILT4-mediated recognition by myelomonocytic cells. This suggests that in addition to abrogating recognition by HIV-1-specific CD8 T cells, mutational escape in some, but not all CTL epitopes may mediate important immunoregulatory effects by increasing binding properties to ILT4, and augmenting ILT4-mediated inhibitory effects of professional antigen-presenting cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • B7-1 Antigen / chemistry
  • CD8-Positive T-Lymphocytes / cytology
  • DNA Mutational Analysis*
  • Epitopes / chemistry
  • Genes, MHC Class I*
  • HIV-1 / metabolism*
  • HLA-B Antigens / chemistry*
  • Histocompatibility Antigens Class I / chemistry*
  • Humans
  • Lipopolysaccharide Receptors / biosynthesis
  • Membrane Glycoproteins / chemistry
  • Monocytes / cytology*
  • Mutation
  • Peptides / chemistry
  • Receptors, Immunologic / chemistry
  • T-Lymphocytes, Cytotoxic / immunology*
  • T-Lymphocytes, Cytotoxic / virology

Substances

  • B7-1 Antigen
  • Epitopes
  • HLA-B Antigens
  • HLA-B57 antigen
  • Histocompatibility Antigens Class I
  • LILRB2 protein, human
  • Lipopolysaccharide Receptors
  • Membrane Glycoproteins
  • Peptides
  • Receptors, Immunologic