Identification of human germinal center light and dark zone cells and their relationship to human B-cell lymphomas

GD Victora, D Dominguez-Sola… - Blood, The Journal …, 2012 - ashpublications.org
GD Victora, D Dominguez-Sola, AB Holmes, S Deroubaix, R Dalla-Favera
Blood, The Journal of the American Society of Hematology, 2012ashpublications.org
Germinal centers (GCs) are sites of B-cell clonal expansion, hypermutation, and selection.
GCs are polarized into dark (DZ) and light zones (LZ), a distinction that is of key importance
to GC selection. However, the difference between the B cells in each of these zones in
humans remains unclear. We show that, as in mice, CXCR4 and CD83 can be used to
distinguish human LZ and DZ cells. Using these markers, we show that LZ and DZ cells in
mice and humans differ only in the expression of characteristic “activation” and “proliferation” …
Abstract
Germinal centers (GCs) are sites of B-cell clonal expansion, hypermutation, and selection. GCs are polarized into dark (DZ) and light zones (LZ), a distinction that is of key importance to GC selection. However, the difference between the B cells in each of these zones in humans remains unclear. We show that, as in mice, CXCR4 and CD83 can be used to distinguish human LZ and DZ cells. Using these markers, we show that LZ and DZ cells in mice and humans differ only in the expression of characteristic “activation” and “proliferation” programs, suggesting that these populations represent alternating states of a single-cell type rather than distinct differentiation stages. In addition, LZ/DZ transcriptional profiling shows that, with the exception of “molecular” Burkitt lymphomas, nearly all human B-cell malignancies closely resemble LZ cells, which has important implications for our understanding of the molecular programs of lymphomagenesis.
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