Identification of two subpopulations of purified human blood B cells, CD27− CD23+ and CD27high CD80+, that strongly express cell surface Toll-like receptor 9 and secrete high levels of interleukin-6
Article first published online: 28 APR 2008
© 2008 Blackwell Publishing Ltd
Volume 125, Issue 3, pages 430–437, November 2008
How to Cite
Cognasse, F., Hamzeh-Cognasse, H., Lafarge, S., Chavarin, P., Pozzetto, B., Richard, Y. and Garraud, O. (2008), Identification of two subpopulations of purified human blood B cells, CD27− CD23+ and CD27high CD80+, that strongly express cell surface Toll-like receptor 9 and secrete high levels of interleukin-6. Immunology, 125: 430–437. doi: 10.1111/j.1365-2567.2008.02844.x
- Issue published online: 8 OCT 2008
- Article first published online: 28 APR 2008
- Received 26 September 2007; revised 14 March 2008; accepted 17 March 2008.
- B cells;
- CpG DNA;
- Toll-like receptors
B-cell expression of certain Toll-like receptors (TLRs) is important in linking innate and adaptive immune responses in normal and pathological conditions. The expression of TLR9 plays a role in the recognition of conserved pathogen motifs in a manner that is dependent on B-cell localization, deduced from B-cell phenotype. The nature of TLR9 function is unclear. A first step in unravelling the function of this pattern recognition receptor is to discover the precise nature of the cell types that express TLR9. This study used three-colour flow cytometry to characterize the B lymphocytes from human peripheral blood mononuclear cells (PBMCs) that express TLR9 on the surface. We sorted TLR9-positive B and non-B cells from the PBMC population and detected TLR9 expression on naïve and memory B cells. Moreover, we identified two discrete subpopulations of B cells: CD19+ CD27− CD23+ cells and CD19+ CD27high CD80+ cells. These subpopulations expressed high levels of membrane TLR9 and exhibited a strong in vitro response to binding a relevant CpG motif by secreting high levels of interleukin-6 (compared to controls). Our finding that this pattern recognition receptor is expressed on a variety of cell subsets adds to the current understanding of the functional complexity of B-cell membrane TLR9.