Cell-mediated antiviral response to equine herpesvirus type 1 demonstrated in a murine infection model by means of adoptive transfer of immune cells.

Protection against equine herpesvirus type 1 (EHV-1) infection in a mouse model has been studied by means of delayed-type hypersensitivity (DTH) and adoptive transfer of immune spleen cells. Mice were found to develop a positive DTH response to EHV-1 antigen which was sustained for several months after primary inoculation. The response was found to cross-react with EHV-4-derived antigen. Immune cells (from mice primed with live or heat-inactivated EHV-1) conferred an enhanced DTH response on recipients; however, only the immune cells that were previously primed with live EHV-1 gave protection against re-infection. The degree of protection was also dependent on the number of spleen cells transferred. Immune cells from mice primed with heat-inactivated EHV-1 appeared to enhance virus replication following subsequent inoculation. The serum antibody response to EHV-1 appeared to be slightly suppressed in recipients of spleen cells from mice primed with either live or heat-inactivated virus. These results support the important role for cell-mediated responses in protective immunity to EHV-1 and provide clues to the nature of protection and immunopathology in the natural host.