IGHV1-69-encoded antibodies expressed in chronic lymphocytic leukemia react with malondialdehyde-acetaldehyde adduct, an immunodominant oxidation-specific epitope

PLoS One. 2013 Jun 20;8(6):e65203. doi: 10.1371/journal.pone.0065203. Print 2013.

Abstract

The immunoglobulins expressed by chronic lymphocytic leukemia (CLL) B cells are highly restricted, suggesting they are selected for binding either self or foreign antigen. Of the immunoglobulin heavy-chain variable (IGHV) genes expressed in CLL, IGHV1-69 is the most common, and often is expressed with little or no somatic mutation, and restricted IGHD and IGHJ gene usage. We found that antibodies encoded by one particular IGHV1-69 subset, designated CLL69C, with the HCDR3 encoded by the IGHD3-3 gene in reading frame 2 and IGHJ6, specifically bound to oxidation-specific epitopes (OSE), which are products of enhanced lipid peroxidation and a major target of innate natural antibodies. Specifically, CLL69C bound immunodominant OSE adducts termed MAA (malondialdehyde-acetaldehyde-adducts), which are found on apoptotic cells, inflammatory tissues, and atherosclerotic lesions. It also reacted specifically with MAA-specific peptide mimotopes. Light chain shuffling indicated that non-stochastically paired L chain of IGLV3-9 contributes to the antigen binding of CLL69C. A nearly identical CLL69C Ig heavy chain was identified from an MAA-enriched umbilical cord phage displayed Fab library, and a derived Fab with the same HCDR3 rearrangement displayed identical MAA-binding properties. These data support the concept that OSE (MAA-epitopes), which are ubiquitous products of inflammation, may play a role in clonal selection and expansion of CLL B cells.

Publication types

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

MeSH terms

  • Acetaldehyde / immunology*
  • Adult
  • Amino Acid Sequence
  • Animals
  • Antibodies, Neoplasm / chemistry
  • Antibodies, Neoplasm / metabolism*
  • Antibody Specificity
  • Apoptosis
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism
  • Base Sequence
  • Epitopes / immunology
  • HEK293 Cells
  • Humans
  • Immunoglobulin Heavy Chains / chemistry
  • Immunoglobulin Heavy Chains / metabolism*
  • Immunoglobulin Light Chains / metabolism
  • Leukemia, Lymphocytic, Chronic, B-Cell / immunology*
  • Lipid Peroxidation
  • Lipoproteins, LDL / immunology
  • Malondialdehyde / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Plaque, Atherosclerotic / immunology
  • Plaque, Atherosclerotic / metabolism
  • Plaque, Atherosclerotic / pathology
  • Protein Binding
  • Rabbits

Substances

  • Antibodies, Neoplasm
  • Epitopes
  • Immunoglobulin Heavy Chains
  • Immunoglobulin Light Chains
  • Lipoproteins, LDL
  • oxidized low density lipoprotein
  • Malondialdehyde
  • Acetaldehyde