Student Abstract

Submitted by Danielle Chorba, Michigan State University

Equine herpesvirus-1 (EHV-1) myeloencephalopathy (EHM) is a detrimental disease affecting horses of all ages, but particularly elderly horses ages 15 and older.  Neurological deficits from EHV-1 infection occur in roughly 10% of infected horses but cause severe impacts. Determining what the differences are in the respiratory tract immune response between infected horses of young and older age groups is crucial for effective vaccine development of EHM. The purpose of this study is to utilize the equine respiratory epithelial cell (EREC) culture system to characterize and compare the respiratory immune response profiles of both horse age groups.

ERECs were inoculated with Ab4-GFP wildtype strain of EHV-1 and collected at 1-, 6-, 12-, 24-, and 48- hours post inoculation (hpi). The RNA from those infected cells were then extracted and converted to cDNA. Real Time Polymerase Chain Reaction (PCR) was used to quantify inflammatory cytokines as a part of the respiratory tract immune response of these horses. Viral load was also determined for each horse using Real Time quantitative PCR from extracted DNA from the infected ERECs.

 We expect there to be a decrease in respiratory tract immune response of the older horse age group as compared to the younger age group. The virus avoids and hides from the host immune system by infecting or “hijacking” immune cells, such as monocytes and T-cells, to promote further infection of secondary lymphoid tissue. We suggest that older horse epithelial cells may be secreting insufficient amounts or types of cytokines, leading to an inappropriate immune response of the host. Determining exactly what those differences are is vital to developing a vaccine that will effectively target the underlying cause of this devastating disease.