TLR8 deficiency leads to autoimmunity in mice
Olivier Demaria, … , Richard A. Flavell, Lena Alexopoulou
Olivier Demaria, … , Richard A. Flavell, Lena Alexopoulou
Published September 1, 2010
Citation Information: J Clin Invest. 2010;120(10):3651-3662. https://doi.org/10.1172/JCI42081.
View: Text | PDF
Research Article Autoimmunity

TLR8 deficiency leads to autoimmunity in mice

Abstract

TLRs play an essential role in the induction of immune responses by detecting conserved molecular products of microorganisms. However, the function of TLR8 is largely unknown. In the current study, we investigated the role of TLR8 signaling in immunity in mice. We found that Tlr8–/– DCs overexpressed TLR7, were hyperresponsive to various TLR7 ligands, and showed stronger and faster NF-κB activation upon stimulation with the TLR7 ligand R848. Tlr8–/– mice showed splenomegaly, defective development of marginal zone (MZ) and B1 B cells, and increased serum levels of IgM and IgG2a. Furthermore, Tlr8–/– mice exhibited increased serum levels of autoantibodies against small nuclear ribonucleoproteins, ribonucleoprotein, and dsDNA and developed glomerulonephritis, whereas neither Tlr7–/– nor Tlr8–/–Tlr7–/– mice showed any of the phenotypes observed in Tlr8–/– mice. These data provide evidence for a pivotal role for mouse TLR8 in the regulation of mouse TLR7 expression and prevention of spontaneous autoimmunity.

Authors

Olivier Demaria, Philippe P. Pagni, Stephanie Traub, Aude de Gassart, Nora Branzk, Andrew J. Murphy, David M. Valenzuela, George D. Yancopoulos, Richard A. Flavell, Lena Alexopoulou

×

Figure 2

Enhanced responses to TLR7 ligands by Tlr8–/– DCs.

Options: View larger image (or click on image) Download as PowerPoint
Enhanced responses to TLR7 ligands by Tlr8–/– DCs. (A) BMDCs from WT...
(A) BMDCs from WT and Tlr8–/– mice were stimulated with the indicated amounts of R848, polyA:U, CpG, polyI:C, and LPS. After 20 hours, the concentrations of IL-6, IL-12p40, and TNF in the culture supernatants were assessed by ELISA. (B) WT and Tlr8–/– BMDCs were left untreated or stimulated for the indicated times with 50 nM R848. Total RNA was extracted from the cells, and expression of Ifnb was assessed by Q-PCR. (C) WT and Tlr8–/– BMDCs were left untreated or stimulated with the indicated amounts of R848 for 16 hours, and cell surface expression of MHCII and CD86 was analyzed by flow cytometry on gated CD11c+ cells. (D) WT and Tlr8–/– CD11c+ splenic cells were isolated by magnetic-activated cell sorting, then left unstimulated or stimulated for 16 hours with 30 nM R848, 10 ng/ml LPS, or 30 nM CpG. The production of IL-12p40 in the culture supernatants was assessed by ELISA. *P < 0.05. (E) WT and Tlr8–/– mice (8 weeks old) were injected i.p. with 100 μl of 10 μM R848. Sera were collected 2 or 6 hours later, and serum levels of IL-6 and IL-12p40 were determined by ELISA. (A, D, and E) Data are mean ± SD of 3–4 (A and D) or 8–10 (E) mice per group and are representative of 2–5 independent experiments. (B) Data are mean ± SD of duplicates and are representative of 2 independent experiments.