Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6113746 | Seminars in Hematology | 2014 | 46 Pages |
Abstract
The B-cell receptor (BCR) is of critical importance for normal B cells and for the majority of B-cell malignancies, especially chronic lymphocytic leukemia (CLL). The two major subsets of CLL are biologically distinct, being derived from B cells at different stages of differentiation and carrying unmutated (U-CLL) or mutated (M-CLL) IGHV genes. U-CLL, which has a poorer prognosis, often has relatively conserved (stereotypic) IGHV-HD-HJ sequences, indicative of interaction with large (super)antigens and similar to those in normal naive innate B cells. Conserved sequences are less evident in M-CLL, in keeping with its postfollicular origin. However, both subsets exhibit features of chronic antigen exposure in tissue sites, with local proliferative events, but also downregulation of surface immunoglobulin M but not surface immunoglobulin D, a characteristic of normal anergic B cells. BCR-mediated anergy can spread to other receptors such as CXCR4. Circulating CLL cells retain a shadow of tissue-based events that can reverse over time, but the overall extent of anergy is greater in M-CLL. Despite this stereotypic variety and more genomic complexity, BCR-mediated responses in vitro appear relatively homogeneous in U-CLL, but M-CLL is more heterogeneous. The differential balance between antigen-induced proliferation or anergy is the likely determinant of clinical behavior and possibly of response to kinase inhibitors.
Related Topics
Health Sciences
Medicine and Dentistry
Hematology
Authors
Freda K. Stevenson, Francesco Forconi, Graham Packham,