Defective Toll-like receptor 9-mediated cytokine production in B cells from Bruton's tyrosine kinase-deficient mice.
Bruton's tyrosine kinase (Btk), a member of the Tec family of tyrosine kinases, plays an important role in the differentiation and activation of B cells. Mutations affecting Btk cause immunodeficiency in both humans and mice. In this study we set out to investigate the potential role of Btk in Toll-like receptor 9 (TLR9) activation and the production of pro-inflammatory cytokines such as interleukin (IL)-6, tumour necrosis factor (TNF)-alpha and IL-12p40. Our data show that Btk-deficient B cells respond more efficiently to CpG-DNA stimulation, producing significantly higher levels of pro-inflammatory cytokines but lower levels of the inhibitory cytokine IL-10. The quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis presented in this work shows that mRNA production of one of the important new members of the IL-12 family, IL-27, was significantly increased in Btk-deficient B cells after CpG-DNA stimulation. In this study, we demonstrate significant differences in CpG responsiveness between transitional 1 (T1) and T2 B cells for survival and maturation. Furthermore, TLR9 expression, measured both as protein and as mRNA, was increased in Btk-defective cells, especially after TLR9 stimulation. Collectively, these data provide evidence in support of the theory that Btk regulates both TLR9 activation and expression in mouse splenic B cells.
Hasan
Maroof
M
Clinical Research Center, Department of Laboratory Medicine, Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden.
Lopez-Herrera
Gabriela
G
Blomberg
K Emelie M
KE
Lindvall
Jessica M
JM
Berglöf
Anna
A
Smith
C I Edvard
CI
Vargas
Leonardo
L
D000077329:Agammaglobulinaemia Tyrosine Kinase; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D020869:Gene Expression Profiling / Q000379:methods; D018836:Inflammation Mediators / Q000378:metabolism; D016753:Interleukin-10 / Q000096:biosynthesis; D007378:Interleukins / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009838:Oligodeoxyribonucleotides / Q000276:immunology; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D051217:Toll-Like Receptor 9 / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology
C408982:CPG-oligonucleotide; D016207:Cytokines; C486767:Il27 protein, mouse; D018836:Inflammation Mediators; D007378:Interleukins; D009838:Oligodeoxyribonucleotides; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9; D016753:Interleukin-10; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; C000625951:Btk protein, mouse