Pennington et al.: First demonstration of equid gammaherpesviruses within the gastric mucosal epithelium of horses. Virus Research volume 242, 15 October 2017, pages 30-36.

The research article discusses the detection and potential path of infection of equine herpes viruses (HV) in gastric ulcers in horses, suggesting that similar processes could be at work in human herpes virus infections.

Introduction and Methodology

• The researchers used in situ hybridization (ISH) to investigate the presence of herpes virus in equine gastric ulcers.
• Their methodology was informed by previous studies that used blotting to identify human herpes virus DNA in peptic ulcers.
• The researchers closely inspected the cells hosting HSV and were puzzled by how these cells were positioned at the ulcerative lesions’ margin.

Results and Findings

• The cells that tested positive for HSV seemed to belong to a unique type of cell – not the regular mucosal epithelial lining cells.
• These unique cells’ distinct pear-shaped appearance indicated they might be specialized enterochromaffine cells.
• Upon applying a combination of in situ hybridization and immunohistochemistry for neuroendocrine cells, these cells were indeed confirmed as enterochromaffine.
• The researchers found it highly likely that the same type of cells was hosting the HSV in the equine stomach ulcers.

Relevance and Implication of Findings

• The study’s findings have important implications, as they point towards a potential route of infection.
• Herpesviridae, which includes herpes viruses, tend to target nervous tissue (neurotrophic).
• According to this neurotropic nature, the authors postulate that the horse herpes virus likely resides in central nervous system nuclei, possibly of the vagus nerve which connects to the stomach.
• This hypothesis was supported by an unpublished study showing HSV travelling down the vagal nerve in mice towards the stomach.
• Conclusively, the identifying of HV on the margin of peptic ulcers both in man and horse, hosted in neuroendocrine cells, further supports the known neurotrophic dormancy and reactivation characteristics of Herpesviridae.