IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition that can affect multiple organs. We previously demonstrated that human Toll-like receptor 7 (huTLR7)-transgenic C57BL/6 mice showed elevated serum IgG1 levels and inflammation with fibrosis in the salivary glands (SGs), lungs, and pancreas. Moreover, we observed extensive TLR7
Gene expression in SGs from huTLR7-transgenic mice and IgG4-RD patients was analyzed using DNA microarrays. We extracted the common upregulated TLR7-related genes in SGs from huTLR7-transgenic mice and IgG4-RD patients. Finally, we investigated the interaction between CD163
In huTLR7-transgenic mice and IgG4-RD patients, IL-1 receptor-associated kinase 3 (IRAK3) and IRAK4 were significantly overexpressed. Real-time PCR validated the upregulation of only IRAK4 in IgG4-RD patients compared with the other groups. IRAK4 was strongly detected in/around germinal centers in SGs from IgG4-DS patients alone. Double immunofluorescence staining showed that IRAK4-positive cells were mainly co-localized with CD163
CD163