Stereotyped patterns of somatic hypermutation in subsets of patients with chronic lymphocytic leukemia: implications for the role of antigen selection in leukemogenesis

Research output: Contribution to journalArticle

Abstract

Somatic hypermutation (SHM) features in a series of 1967 immunoglobulin heavy chain gene (IGH) rearrangements obtained from patients with chronic lymphocytic leukemia (CLL) were examined and compared with IGH sequences from non-CLL B cells available in public databases. SHM analysis was performed for all 1290 CLL sequences in this cohort with less than 100% identity to germ line. At the cohort level, SHM patterns were typical of a canonical SHM process. However, important differences emerged from the analysis of certain subgroups of CLL sequences defined by: (1) IGHV gene usage, (2) presence of stereotyped heavy chain complementarity-determining region 3 (HCDR3) sequences, and (3) mutational load. Recurrent, "stereotyped" amino acid changes occurred across the entire IGHV region in CLL subsets carrying stereotyped HCDR3 sequences, especially those expressing the IGHV3-21 and IGHV4-34 genes. These mutations are un-derrepresented among non-CLL sequences and thus can be considered as CLL-biased. Furthermore, it was shown that even a low level of mutations may be functionally relevant, given that stereotyped amino acid changes can be found in subsets of minimally mutated cases. The precise targeting and distinctive features of somatic hypermutation (SHM) in selected subgroups of CLL patients provide further evidence for selection by specific antigenic element(s).

Details

Authors
  • Fiona Murray
  • Nikos Darzentas
  • Anastasia Hadzidimitriou
  • Gerard Tobin
  • Myriarn Boudjogra
  • Cristina Scielzo
  • Nikolaos Laoutaris
  • Karin Karlsson
  • Fanny Baran-Marzsak
  • Athanasios Tsaftaris
  • Carol Moreno
  • Achilles Anagnostopoulos
  • Federico Caligaris-Cappio
  • Dominique Vaur
  • Christos Ouzounis
  • Chrysoula Belessi
  • Paolo Ghia
  • Fred Davi
  • Richard Rosenquist
  • Kostas Stamatopoulos
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Hematology
Original languageEnglish
Pages (from-to)1524-1533
JournalBlood
Volume111
Issue number3
Publication statusPublished - 2008
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Hematology/Transplantation (013022014)