IGHV1-69 B cell chronic lymphocytic leukemia antibodies cross-react with HIV-1 and hepatitis C virus antigens as well as intestinal commensal bacteria

PLoS One. 2014 Mar 10;9(3):e90725. doi: 10.1371/journal.pone.0090725. eCollection 2014.

Abstract

B-cell chronic lymphocytic leukemia (B-CLL) patients expressing unmutated immunoglobulin heavy variable regions (IGHVs) use the IGHV1-69 B cell receptor (BCR) in 25% of cases. Since HIV-1 envelope gp41 antibodies also frequently use IGHV1-69 gene segments, we hypothesized that IGHV1-69 B-CLL precursors may contribute to the gp41 B cell response during HIV-1 infection. To test this hypothesis, we rescued 5 IGHV1-69 unmutated antibodies as heterohybridoma IgM paraproteins and as recombinant IgG1 antibodies from B-CLL patients, determined their antigenic specificities and analyzed BCR sequences. IGHV1-69 B-CLL antibodies were enriched for reactivity with HIV-1 envelope gp41, influenza, hepatitis C virus E2 protein and intestinal commensal bacteria. These IGHV1-69 B-CLL antibodies preferentially used IGHD3 and IGHJ6 gene segments and had long heavy chain complementary determining region 3s (HCDR3s) (≥21 aa). IGHV1-69 B-CLL BCRs exhibited a phenylalanine at position 54 (F54) of the HCDR2 as do rare HIV-1 gp41 and influenza hemagglutinin stem neutralizing antibodies, while IGHV1-69 gp41 antibodies induced by HIV-1 infection predominantly used leucine (L54) allelic variants. These results demonstrate that the B-CLL cell population is an expansion of members of the innate polyreactive B cell repertoire with reactivity to a number of infectious agent antigens including intestinal commensal bacteria. The B-CLL IGHV1-69 B cell usage of F54 allelic variants strongly suggests that IGHV1-69 B-CLL gp41 antibodies derive from a restricted B cell pool that also produces rare HIV-1 gp41 and influenza hemagglutinin stem antibodies.

Publication types

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

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Antibodies, Monoclonal / immunology
  • Antibodies, Neoplasm / immunology*
  • Bacteria / immunology*
  • Cell Line, Tumor
  • Cross Reactions / immunology*
  • HIV Antigens / chemistry
  • HIV Antigens / immunology*
  • HIV Infections / immunology
  • HIV-1 / immunology
  • Hepacivirus / immunology
  • Hepatitis C Antigens / immunology*
  • Humans
  • Hybridomas / immunology
  • Immunoglobulin Heavy Chains
  • Immunoglobulin Variable Region
  • Intestines / microbiology*
  • Leukemia, Lymphocytic, Chronic, B-Cell / immunology*
  • Molecular Sequence Data
  • Paraproteins / metabolism
  • Protein Binding
  • Receptors, Antigen, B-Cell / immunology*
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Symbiosis
  • Treatment Outcome

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neoplasm
  • HIV Antigens
  • Hepatitis C Antigens
  • IGHV1-69 protein, human
  • Immunoglobulin Heavy Chains
  • Immunoglobulin Variable Region
  • Paraproteins
  • Receptors, Antigen, B-Cell
  • Recombinant Proteins