A West Nile virus NS4B-P38G mutant strain induces cell intrinsic innate cytokine responses in human monocytic and macrophage cells

Guorui Xie, Huanle Luo, Bing Tian, Brian Mann, Xiaoyong Bao, Jere McBride, Robert Tesh, Alan D. Barrett, Tian Wang

Research output: Contribution to journalArticle

4 Scopus citations


Previous studies have shown that an attenuated West Nile virus (WNV) nonstructural (NS) 4B-P38G mutant induces stronger innate and adaptive immune responses than wild-type WNV in mice, which has important applications to vaccine development. To investigate the mechanism of immunogenicity, we characterized WNV NS4B-P38G mutant infection in two human cell lines-THP-1 cells and THP-1 macrophages. Although the NS4B-P38G mutant produced more viral RNA than the parental WNV NY99 in both cell types, there was no detectable infectious virus in the supernatant of either cell type. Nonetheless, the attenuated mutant boosted higher innate cytokine responses than virulent parental WNV NY99 in these cells. The NS4B-P38G mutant infection of THP-1 cells led to more diverse and robust innate cytokine responses than that seen in THP-1 macrophages, which were mediated by toll-like receptor (TLR)7 and retinoic acid-inducible gene 1(RIG-I) signaling pathways. Overall, these results suggest that a defective viral life cycle during NS4B-P38G mutant infection in human monocytic and macrophage cells leads to more potent cell intrinsic innate cytokine responses.

Original languageEnglish (US)
Pages (from-to)869-878
Number of pages10
Issue number7
StatePublished - Feb 11 2015



  • Cytokine
  • Immune response
  • NS4B protein
  • West Nile virus

ASJC Scopus subject areas

  • Molecular Medicine
  • Immunology and Microbiology(all)
  • veterinary(all)
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

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