Details

Autor(en) / Beteiligte

• Zentsova, Irena
• Parackova, Zuzana
• Kayserova, Jana
• Palova-Jelinkova, Lenka
• Vrabcova, Petra
• Volfova, Nikol
• Sumnik, Zdenek
• Pruhova, Stepanka
• Petruzelkova, Lenka
• Sediva, Anna

Titel

Monocytes contribute to DNA sensing through the TBK1 signaling pathway in type 1 diabetes patients

Ist Teil von

• Journal of autoimmunity, 2019-12, Vol.105, p.102294-102294, Article 102294

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2019

Quelle

ScienceDirect

Beschreibungen/Notizen

• The aberrant recognition of self-nucleic acids by the innate immune system contributes to the pathology of several autoimmune diseases. Although microbial DNA and, in certain instances, self-DNA that is released from damaged cells are primarily recognized by Toll-like receptor 9 (TLR9), recent evidence suggests that other cytosolic sequence-nonspecific DNA sensors contribute to DNA recognition. In this study, we focused on the sensing of microbial and host DNA in type 1 diabetes (T1D) patients. Peripheral blood mononuclear cells (PBMCs) and monocytes from pediatric patients with T1D and from healthy donors were stimulated with microbial DNA (CpG) or with self-DNA (DNA contained within neutrophil extracellular traps, NETs). The production of cytokines was measured by flow cytometry and multiplex bead assays. The internalization of microbial DNA and its colocalization with STING was detected by image cytometry. Furthermore, the involvement of the TBK1 kinase was investigated by detecting its phosphorylation with phospho-flow cytometry or by using a TBK1 inhibition assay. We observed a prominent proinflammatory response in T1D PBMCs, especially pDCs and monocytes, to microbial DNA in comparison to that in controls. We further confirmed that monocytes could bind and internalize DNA and respond by releasing proinflammatory cytokines in a more pronounced manner in T1D patients than those in controls. Surprisingly, this cytokine production was not affected by TLR9 blockade, suggesting the involvement of intracellular receptors in DNA recognition. We further identified TBK1 and STING as two crucial molecules in the DNA-sensing pathway that were involved in CpG-DNA sensing by T1D cells. A similar DNA-sensing pathway that was dependent on intracellular DNA sensors and the STING-TBK1 interaction was employed in response to NETs, which were used to model self-DNA. Here, we show that there were significant differences in DNA sensing in T1D patients compared to that in controls. We demonstrate that monocytes from T1D patients are able to sense microbial- and self-DNA, leading to proinflammatory cytokine secretion through the adaptor protein STING and the TBK1 kinase. •Monocytes, besides pDCs, markedly participate in nucleic acid recognition in T1D patients.•CpG-DNA recognition leads to excessive proinflammatory cytokine and IFN release in T1D patient monocytes.•CpG-DNA sensing in pDCs and monocytes proceeds through the TLR9 and intracellular receptor pathways.•TBK1 and STING are two crucial molecules that are involved in intracellular DNA sensing.