Local CD4 and CD8 T-cell reactivity to HSV-1 antigens documents broad viral protein expression and immune competence in latently infected human trigeminal ganglia

PLoS Pathog. 2013 Aug;9(8):e1003547. doi: 10.1371/journal.ppat.1003547. Epub 2013 Aug 15.

Abstract

Herpes simplex virus type 1 (HSV-1) infection results in lifelong chronic infection of trigeminal ganglion (TG) neurons, also referred to as neuronal HSV-1 latency, with periodic reactivation leading to recrudescent herpetic disease in some persons. HSV-1 proteins are expressed in a temporally coordinated fashion during lytic infection, but their expression pattern during latent infection is largely unknown. Selective retention of HSV-1 reactive T-cells in human TG suggests their role in controlling reactivation by recognizing locally expressed HSV-1 proteins. We characterized the HSV-1 proteins recognized by virus-specific CD4 and CD8 T-cells recovered from human HSV-1-infected TG. T-cell clusters, consisting of both CD4 and CD8 T-cells, surrounded neurons and expressed mRNAs and proteins consistent with in situ antigen recognition and antiviral function. HSV-1 proteome-wide scans revealed that intra-TG T-cell responses included both CD4 and CD8 T-cells directed to one to three HSV-1 proteins per person. HSV-1 protein ICP6 was targeted by CD8 T-cells in 4 of 8 HLA-discordant donors. In situ tetramer staining demonstrated HSV-1-specific CD8 T-cells juxtaposed to TG neurons. Intra-TG retention of virus-specific CD4 T-cells, validated to the HSV-1 peptide level, implies trafficking of viral proteins from neurons to HLA class II-expressing non-neuronal cells for antigen presentation. The diversity of viral proteins targeted by TG T-cells across all kinetic and functional classes of viral proteins suggests broad HSV-1 protein expression, and viral antigen processing and presentation, in latently infected human TG. Collectively, the human TG represents an immunocompetent environment for both CD4 and CD8 T-cell recognition of HSV-1 proteins expressed during latent infection. HSV-1 proteins recognized by TG-resident T-cells, particularly ICP6 and VP16, are potential HSV-1 vaccine candidates.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antigens, Viral / immunology*
  • Antigens, Viral / metabolism
  • Autopsy
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / metabolism
  • CD4-Positive T-Lymphocytes / virology
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • CD8-Positive T-Lymphocytes / virology
  • Cytokines / metabolism
  • DNA, Viral / genetics
  • Fluorescent Antibody Technique
  • Herpes Simplex / immunology*
  • Herpes Simplex / metabolism
  • Herpes Simplex / virology
  • Herpesvirus 1, Human / physiology*
  • Humans
  • Middle Aged
  • Neurons / immunology
  • Neurons / metabolism
  • Neurons / virology
  • Trigeminal Ganglion / cytology
  • Trigeminal Ganglion / immunology
  • Trigeminal Ganglion / virology*
  • Viral Proteins / immunology
  • Viral Proteins / metabolism*
  • Virus Latency / immunology*

Substances

  • Antigens, Viral
  • Cytokines
  • DNA, Viral
  • Viral Proteins