Selected TLR7/8 agonist and type I interferon (IFN-α) cooperatively redefine the microglia transcriptome

  • Mst Reshma Khatun
  • Sarder ArifuzzamanEmail author
Original Article



Microglia, the primary immune cells of the central nervous system, exerts multiple functions to mediate many neurological diseases. Upon any detection of invading pathogen products (e.g., TLR agonists) or host-released signaling factors (e.g., interferon/IFN), these cells undergo an activation process to release large numbers of inflammatory substances that participate in inflammation and homeostasis. The profound effects of inflammation associated with TLR7/8 agonist Resiquimod (R848) and type 1 interferon (e.g., IFN-α)-induced macrophage and dendritic cell activation on biological outcomes have long been recognized. However, the underlying mechanisms are not well defined in microglial cells.


The present study investigated the molecular signatures of microglia and identified genes that are uniquely or synergistically expressed in R848-, IFN-α- or R848 with IFN-α-treated primary microglial (PM) cells. We used RNA-sequencing, quantitative real-time PCR, and bioinformatics approaches to derive regulatory networks that control the transcriptional response of PM to R848, IFN-α and R848 with IFN-α.


Our approach revealed that the inflammatory response in R848 with IFN-α-treated PM is faster and more intense than that in R848 or IFN-α-treated PM in terms of the number of differentially expressed genes and the magnitude of induction/repression. In particular, our integrative analysis enabled us to suggest the regulatory functions of TFs, which allowed the construction of a network model that explains how TLR7/8 and IFN-α-sensing pathways achieve specificity.


In conclusion, the systematic approach presented herein could be important to the understanding microglial activation-mediated molecular signatures induced by inflammatory stimuli related to TLR7/8, IFN-α or co-signaling, and associated transcriptional machinery of microglial functions and neuroinflammatory mechanisms.


Microglial RNA sequencing Transcription factors Type 1 interferons Toll-like receptor 



Biological process


Central nervous system


Cerebrospinal fluid


Cyclic AMP


Signal transduction and activation of transcription


Interferon regulatory factors


Database for annotation, visualization and integrated discovery


Differentially expressed gene


Dulbecco’s modified Eagle’s medium


Experimental autoimmune encephalomyelitis




Fetal bovine serum


Glyceraldehyde-3-phosphate dehydrogenase


Gene ontology


Growth-regulated oncogenes


Histone deacetylase genes


Heme oxygenase


Institutional animal care and use committee


IFN-induced protein with tetratricopeptide






Ingenuity pathway analysis


IFN-stimulated gene


Lysine (K)-specific demethylase


Kruppel-like factor






Monocyte chemoattractant proteins


Macrophage colony-stimulating factor


Molecular function


Multiple sclerosis


Principal component analysis


Principle component


Prostaglandin E2


Primary microglia


RNA sequencing


Reactive oxygen species


Stromal-derived factor


Traumatic brain injury


Transcription factor


Transforming growth factor beta


Toll-like receptor


Tumor necrosis factor-alpha



This work was supported by Chung-Ang University Young Scientist Scholarship (CAYSS) program.

Author contributions

MRK and SA conceived the study and interpreted the data.

Compliance with ethical standards

Conflict of interest

The authors declare no conflicts of interest related to this work.

Ethics approval and consent to participate

All experimental protocols were performed in accordance with Institutional Animal Care and Use Committee (IACUC) guidelines and approved by the IACUC committee of Chung-Ang University.

Supplementary material

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Supplementary material 1 (TIFF 6863 kb)
10787_2019_610_MOESM2_ESM.tif (3.3 mb)
Supplementary material 2 (TIFF 3427 kb)


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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Biomedical ScienceAjou UniversitySuwonRepublic of Korea
  2. 2.Department of Animal Science and TechnologyChung-Ang UniversityAnseongRepublic of Korea

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