Herpes simplex virus-1 evasion of CD8+ T cell accumulation contributes to viral encephalitis

J Clin Invest. 2017 Oct 2;127(10):3784-3795. doi: 10.1172/JCI92931. Epub 2017 Sep 11.

Abstract

Herpes simplex virus-1 (HSV-1) is the most common cause of sporadic viral encephalitis, which can be lethal or result in severe neurological defects even with antiviral therapy. While HSV-1 causes encephalitis in spite of HSV-1-specific humoral and cellular immunity, the mechanism by which HSV-1 evades the immune system in the central nervous system (CNS) remains unknown. Here we describe a strategy by which HSV-1 avoids immune targeting in the CNS. The HSV-1 UL13 kinase promotes evasion of HSV-1-specific CD8+ T cell accumulation in infection sites by downregulating expression of the CD8+ T cell attractant chemokine CXCL9 in the CNS of infected mice, leading to increased HSV-1 mortality due to encephalitis. Direct injection of CXCL9 into the CNS infection site enhanced HSV-1-specific CD8+ T cell accumulation, leading to marked improvements in the survival of infected mice. This previously uncharacterized strategy for HSV-1 evasion of CD8+ T cell accumulation in the CNS has important implications for understanding the pathogenesis and clinical treatment of HSV-1 encephalitis.

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / pathology
  • Chemokine CXCL9 / genetics
  • Chemokine CXCL9 / immunology
  • Chlorocebus aethiops
  • Encephalitis, Herpes Simplex / genetics
  • Encephalitis, Herpes Simplex / immunology*
  • Encephalitis, Herpes Simplex / pathology
  • Herpesvirus 1, Human / genetics
  • Herpesvirus 1, Human / immunology*
  • Immune Evasion*
  • Immunity, Cellular / genetics
  • Mice
  • Mice, Knockout
  • Protein Kinases / immunology
  • Rabbits
  • Vero Cells

Substances

  • Chemokine CXCL9
  • Cxcl9 protein, mouse
  • Protein Kinases
  • UL13 protein, Simplexvirus