Examination of neuro-inflammation and senescence in brainstem of aged mice latently infected with human alphaherpesvirus 1 (HSV-1)

Virus Res. 2024 Sep:347:199420. doi: 10.1016/j.virusres.2024.199420. Epub 2024 Jun 21.

Abstract

Human alphaherpesvirus 1 (HSV-1) establishes life-long latency in sensory neurons in trigeminal ganglia (TG), brainstem neurons, and other CNS neurons. Two important segments of the brainstem were examined in this study: principal sensory nucleus of the spinal trigeminal tract (Pr5) because it receives direct afferent inputs from TG, and locus coeruleus (LC) because it is indirectly connected to Pr5 and LC sends axonal projections to cortical structures, which may facilitate viral spread from brainstem to the brain. The only viral gene abundantly expressed during latency is the latency associated transcript (LAT). Previous studies revealed 8-week old female C57Bl/6 mice infected with a LAT null mutant (dLAT2903) versus wild-type (wt) HSV-1 exhibit higher levels of senescence markers and inflammation in LC of females. New studies revealed 1-year old mice latently infected with wt HSV-1 or dLAT2903 contained differences in neuroinflammation and senescence in Pr5 and LC versus young mice. In summary, these studies confirm HSV-1 promotes neuro-inflammation in the brainstem, which may accelerate neurodegenerative disease.

Keywords: Brainstem; Gender specific effects; HSV-1; LAT; Neuroinflammation and senescence.

MeSH terms

  • Aging
  • Animals
  • Brain Stem* / pathology
  • Brain Stem* / virology
  • Disease Models, Animal
  • Female
  • Herpes Simplex / pathology
  • Herpes Simplex / virology
  • Herpesvirus 1, Human* / genetics
  • Herpesvirus 1, Human* / physiology
  • Humans
  • Latent Infection / virology
  • Mice
  • Mice, Inbred C57BL*
  • Neuroinflammatory Diseases* / pathology
  • Neuroinflammatory Diseases* / virology
  • Trigeminal Ganglion / virology
  • Virus Latency*