Fellow: Camille Holmes

Mentor: Bettina Wagner

DESCRIPTION (provided by applicant): 

Equine herpesvirus type 1 (EHV-1) is a highly prevalent respiratory pathogen of the horse, which has devastating impact on horse health and the economy of the industry. The virus enters through the nose where it undergoes primary replication. Prior work suggests that the magnitude of EHV-1 specific T cell populations prior to infection are a positive indicator of protection against the virus, however this has been focused on systemic rather than the local nasal T cell population. The mucosal immune system represents the first line of defense in response to pathogens, consisting of diverse cell populations that provide both physical and chemical barriers from the external environment. T cells can be found within the mucus, the epithelial layer, and nasal associated lymphoid tissue (NALT), where they can detect antigen and initiate an adaptive response. Here we seek to investigate the frequency of T cell populations in the nose of the horse and their responsiveness to EHV-1 exposure. Robust mucosal immunity at the site of infection can reduce viral entry into the tissue, and lead to mild or absent clinical signs of respiratory disease. Without viral entry, the risk of viremia is eliminated, and severe disease manifestations such as EHM and abortion do not occur. T cells at the site of viral entry likely contribute to this first line of defense. To assess the nasal T cell populations, we will collect three nasal samples at varying depths of the mucosa from horses who are either immune or susceptible to EHV-1. Cells will be phenotype based on markers for cytotoxic (CD8) or helper (CD4) T cells and stimulated in culture to determine EHV-1 specificity, and their ability to respond to infection. Together this will give a first look into the T cell populations found within the nose and determine if they can contribute to immunity upon EHV-1 exposure.