CD27 in defining memory B-cell origins in Waldenström's macroglobulinemia.
CD27 is a tumor necrosis factor receptor family glycoprotein, identified in seminal studies as an apparently robust marker for normal memory B cells. Somatic hypermutation (SHM) in immunoglobulin variable (V) region genes, however, remains the definitive memory imprint. In Waldenström's macroglobulinemia (WM), SHM defines a predominant mutated (MUT) subset and a minor unmutated subset indicative of naive B-cell origin. In MUT-WM, tumor cells can lack CD27 expression, raising suggestions of unusual memory B-cell origins. We recently identified such normal IgM+D+CD27-ve memory B-cells, with low levels of SHM in VH genes. While these could seed WM, the possibility remains that WM could derive from classical memory B cells that shed CD27. The utility of CD27 expression in defining memory in MUT-WM origins, then, is uncertain, but SHM unequivocally defines memory B-cell derivation in most WM. Patterns of SHM and additional IgH locus events furthermore reveal ongoing intra-tumoral diversification in WM.
Cancer Sciences Division, School of Medicine, University of Southampton, UK. s.s.sahota@soton.ac.uk
Surinder S
SS
Sahota
Gavin
G
Babbage
Nicola J
NJ
Weston-Bell
D001402:B-Lymphocytes / Q000276:immunology*; D006801:Humans; D007156:Immunologic Memory; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D008258:Waldenstrom Macroglobulinemia / Q000235:genetics / Q000276:immunology*
D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7