Altered HLA Class I Profile Associated with Type A/D Nucleophosmin Mutation Points to Possible Anti-Nucleophosmin Immune Response in Acute Myeloid Leukemia

PLoS One. 2015 May 20;10(5):e0127637. doi: 10.1371/journal.pone.0127637. eCollection 2015.

Abstract

Nucleophosmin 1 (NPM1) mutations are frequently found in patients with acute myeloid leukemia (AML) and the newly generated sequences were suggested to induce immune response contributing to the relatively favorable outcome of patients in this AML subset. We hypothesized that if an efficient immune response against mutated nucleophosmin can be induced in vivo, the individuals expressing HLA alleles suitable for presenting NPM-derived peptides should be less prone to developing AML associated with NPM1 mutation. We thus compared HLA class I frequencies in a cohort of patients with mutated NPM1 (63 patients, NPMc+), a cohort of patients with wild-type NPM1 (94 patients, NPMwt) and in normal individuals (large datasets available from Allele Frequency Net Database). Several HLA allelic groups were found to be depleted in NPMc+ patients, but not in NPMwt compared to the normal distribution. The decrease was statistically significant for HLA B(*)07, B(*)18, and B(*)40. Furthermore, statistically significant advantage in the overall survival was found for patients with mutated NPM1 expressing at least one of the depleted allelic groups. The majority of the depleted alleles were predicted to bind potent NPM-derived immunopeptides and, importantly, these peptides were often located in the unmutated part of the protein. Our analysis suggests that individuals expressing specific HLA allelic groups are disposed to develop an efficient anti-AML immune response thanks to aberrant cytoplasmic localization of the mutated NPM protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Case-Control Studies
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Immunity*
  • Leukemia, Myeloid, Acute / immunology*
  • Middle Aged
  • Molecular Sequence Data
  • Mutant Proteins / chemistry
  • Mutant Proteins / metabolism
  • Mutation / genetics*
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / immunology*
  • Nucleophosmin
  • Peptides / chemistry
  • Peptides / immunology
  • Survival Analysis

Substances

  • Histocompatibility Antigens Class I
  • Mutant Proteins
  • NPM1 protein, human
  • Nuclear Proteins
  • Peptides
  • Nucleophosmin

Grants and funding

The work was supported by the Ministry of Health of the Czech Republic (Project for conceptual development of research organization No 00023736). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.