TLR3 and TLR4 are innate antiviral immune receptors in human microglia: Role of IRF3 in modulating antiviral and inflammatory response in the CNS

Hyeon Sook Suh, Meng Liang Zhao, Namjong Choi, Thomas J. Belbin, Celia F. Brosnan, Sunhee C. Lee

Research output: Contribution to journalArticle

45 Scopus citations


In the CNS, microglia are the primary targets of HIV infection. In this study, we investigated the effect of activation of the innate antiviral receptors TLR3 and TLR4 on HIV infection of primary human microglia, as well as microglial cell signaling and gene expression. Ligands for both TLR3 and TLR4 potently inhibited HIV replication in microglia through a pathway requiring IRF3. Surprisingly, a remarkably similar pattern of cell signaling and gene expression was observed in TLR3- and TLR4-activated microglia, suggesting a relatively minor role for MyD88 following TLR4 activation in these cells. HIV did not activate IRF3 but rather decreased IRF3 protein, indicating that HIV does not activate TLR3 or RIG-like helicases in microglia. Taken together, these results indicate that activation of TLR3 or TLR4 will elicit antiviral immunity, in addition to inducing proinflammatory responses. We suggest that a balanced expression between inflammatory and innate immune genes might be achieved by IRF3 over-expression.

Original languageEnglish (US)
Pages (from-to)246-259
Number of pages14
Issue number2
StatePublished - Sep 30 2009



  • Cytokines
  • HIV
  • IRF3
  • Microglia
  • Toll-like receptor

ASJC Scopus subject areas

  • Virology

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