Basal Ca2+ signaling is particularly increased in mutated chronic lymphocytic leukemia

A. F. Muggen, S. Y. Pillai, L. P. Kil, M. C. Van Zelm, J. J M Van Dongen, R. W. Hendriks, A. W. Langerak

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

On the basis of somatic hypermutation status of their B-cell antigen receptor (BCR) genes, chronic lymphocytic leukemia (CLL) patients can be divided into unmutated CLL (U-CLL) or mutated CLL (M-CLL). Approximately 30% of CLL patients express a stereotypic BCR, which may indicate that specific antigenic stimulation is driving CLL pathogenesis. Recently, it was reported that BCRs from CLL cells are capable of antigen-independent, cell-autonomous signaling, through recognition of an internal framework 2 (FR2) BCR epitope. We hypothesized that the level of cell-autonomous signaling may differ between CLL subgroups. Therefore, we analyzed Ca 2+ signaling in a series of primary stereotypic or heterogeneous U-CLL and M-CLL (n=68) and healthy controls (n=14). We confirmed that basal Ca 2+ signaling in CLL cells is higher than in normal B cells. Interestingly, we found that basal signaling was particularly increased in M-CLL. The degree of basal signaling did not correlate with membrane immunoglobulin levels, HCDR3 characteristics or FR2/FR3 sequence. We conclude that the level of basal Ca 2+ signaling is not uniformly enhanced in CLL B cells, but is associated with CLL immunoglobulin heavy chain V mutational status, reflecting a distinct cellular origin and possibly a different anergic state induced by repetitive or continuous antigen binding in vivo.

Original languageEnglish
Pages (from-to)321-328
Number of pages8
JournalLeukemia
Volume29
Issue number2
DOIs
Publication statusPublished - 7 Feb 2015
Externally publishedYes

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