Bovine herpesvirus 1 downregulates the expression of bovine MHC class I molecules

Viral Immunol. 1997;10(1):21-34. doi: 10.1089/vim.1997.10.21.


The mechanism of immunosuppression induced by bovine herpesvirus 1 (BHV-1) was investigated by studying the effects of the virus on the expression of major histocompatibility complex (MHC) class I molecules. After infection with the virus, the expression of class I molecules was detected by flow cytometry and pulse-chase analysis. A selective downregulation of expression of class I molecules was seen in the infected cells, while the class II expression remained unaffected. The reduction in surface expression was evident as early as 8 hours postinfection, reaching significant levels by 12 hours. The downregulation was seen with a multiplicity of infection as low as 0.1. A modified live vaccine strain of BHV-1 also induced the downregulation of class I expression. Analysis of the viral proteins(s) involved in this downregulation with metabolic inhibitors (cycloheximide or phosphonoacetic acid), suggested that the immediate early and/or early proteins of the virus mediate this effect. Pulse-chase analysis revealed that the synthesis of the class I heavy chain, and the assembly/transport of class I molecules were affected by the virus infection. These results suggest that BHV-1 interferes with the molecular mechanisms involved in the synthesis, and assembly/transport of MHC-class I molecules. This interference with the class I antigen processing pathway might help the virus to evade the cytotoxic T-lymphocyte response of the host.

MeSH terms

  • Animals
  • Cattle
  • Cell Line
  • Cell Membrane / immunology
  • Cycloheximide / pharmacology
  • Down-Regulation*
  • Electrophysiology
  • Gene Expression Regulation, Viral*
  • Genes, MHC Class I*
  • Heat-Shock Response
  • Herpesvirus 1, Bovine / immunology*
  • Phosphonoacetic Acid / pharmacology
  • Protein Synthesis Inhibitors / pharmacology
  • Viral Proteins / antagonists & inhibitors
  • Viral Proteins / biosynthesis


  • Protein Synthesis Inhibitors
  • Viral Proteins
  • Cycloheximide
  • Phosphonoacetic Acid