The human Burkitt lymphoma cell line Namalwa represents a homogenous cell system characterized by high levels of Toll-like receptor 9 and activation by CpG oligonucleotides

• Published in: Journal of immunological methods 2005-05, Vol.300 (1), p.93-99
• Main Authors: Henault, Martin, Lee, Linda N., Evans, Glenn F., Zuckerman, Steven H.
• Format: Article
• Language: English
• Subjects: B-Lymphocytes - drug effects; B-Lymphocytes - immunology; B-Lymphocytes - metabolism; Base Sequence; Biological and medical sciences; Burkitt lymphoma; Burkitt Lymphoma - genetics; Burkitt Lymphoma - immunology; Burkitt Lymphoma - metabolism; Cell Line, Transformed; Cell Line, Tumor; Costimulator molecules; Cytokines; Cytokines - biosynthesis; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Gene Expression - drug effects; Humans; Lymphocyte Activation - drug effects; Membrane Glycoproteins - genetics; Molecular immunology; Oligodeoxyribonucleotides - pharmacology; Receptors, Cell Surface - genetics; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Neoplasm - genetics; RNA, Neoplasm - metabolism; Signal Transduction; Techniques; Toll-Like Receptor 9; Toll-Like Receptors
• ISSN: 0022-1759; 1872-7905
• DOI: 10.1016/j.jim.2005.02.012

Human B cells and plasmacytoid dendritic cells constitutively express Toll-like receptor (TLR)9 and respond to TLR9 ligands, as evidenced by nuclear factor kappa B translocation and cytokine secretion. However, TLR9 expression on B lymphocytes appears to be dependent upon both the state of activation and differentiation of the B cell population. In the current study, TLR9 mRNA expression was evaluated in transformed human B cell lines and correlated with their response to CpG. Among the B cell lines, the Burkitt lymphoma-derived Namalwa line had the highest level of TLR9 expression, 20-fold greater than spleen. Following incubation with CpG oligonucleotide, Namalwa cells secreted increased amounts of TNF, IL-6, and IL-10 and expressed the costimulator molecules CD40, CD80, and CD86. These functional responses to TLR9 activation occurred with similar EC 50 values in the 30- to 60-nM range. These results suggest that the Namalwa Burkitt lymphoma line may serve as a useful cell-based assay for the detection of novel TLR9 agonists as well as a model to further explore the regulation of TLR9 expression and signaling.