Comparison of human B cell activation by TLR7 and TLR9 agonists.
BACKGROUND
Human B cells and plasmacytoid dendritic cells (pDC) are the only cells known to express both TLR7 and TLR9. Plasmacytoid dendritic cells are the primary IFN-alpha producing cells in response to TLR7 and TLR9 agonists. The direct effects of TLR7 stimulation on human B cells is less understood. The objective of this study was to compare the effects of TLR7 and TLR9 stimulation on human B cell function.


RESULTS
Gene expression and protein production of cytokines, chemokines, various B cell activation markers, and immunoglobulins were evaluated. Purified human CD19+ B cells (99.9%, containing both naïve and memory populations) from peripheral blood were stimulated with a TLR7-selective agonist (852A), TLR7/8 agonist (3M-003), or TLR9 selective agonist CpG ODN (CpG2006). TLR7 and TLR9 agonists similarly modulated the expression of cytokine and chemokine genes (IL-6, MIP1 alpha, MIP1 beta, TNF alpha and LTA), co-stimulatory molecules (CD80, CD40 and CD58), Fc receptors (CD23, CD32), anti-apoptotic genes (BCL2L1), certain transcription factors (MYC, TCFL5), and genes critical for B cell proliferation and differentiation (CD72, IL21R). Both agonists also induced protein expression of the above cytokines and chemokines. Additionally, TLR7 and TLR9 agonists induced the production of IgM and IgG. A TLR8-selective agonist was comparatively ineffective at stimulating purified human B cells.


CONCLUSIONS
These results demonstrate that despite their molecular differences, the TLR7 and TLR9 agonists induce similar genes and proteins in purified human B cells.
Hanten
John A
JA
Department of Pharmacology, 3M Pharmaceuticals, St Paul, MN 55144, USA. jahanten@mmm.com
Vasilakos
John P
JP
Riter
Christie L
CL
Neys
Lori
L
Lipson
Kenneth E
KE
Alkan
Sefik S
SS
Birmachu
Woubalem
W
D000917:Antibody Formation / Q000187:drug effects / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D016207:Cytokines / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007156:Immunologic Memory; D008213:Lymphocyte Activation / Q000187:drug effects* / Q000276:immunology; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D051199:Toll-Like Receptor 7 / Q000819:agonists / Q000276:immunology*; D051200:Toll-Like Receptor 8 / Q000819:agonists / Q000276:immunology*; D051217:Toll-Like Receptor 9 / Q000819:agonists / Q000276:immunology*
C526117:3M 002; C513533:CpG ODN 2006; D016207:Cytokines; D007093:Imidazoles; C523097:N-(4-(4-amino-2-ethyl-1H-imidazo(4,5c)quinolin-1-yl)butyl)methanesulfonamide; D009838:Oligodeoxyribonucleotides; D011804:Quinolines; D013449:Sulfonamides; C495348:TLR7 protein, human; C495349:TLR8 protein, human; C495371:TLR9 protein, human; D051199:Toll-Like Receptor 7; D051200:Toll-Like Receptor 8; D051217:Toll-Like Receptor 9