Novel IFN-γ ELISpot reveals robust T cell responses elicited after influenza nucleoprotein DNA vaccination in New Zealand White rabbits.

The New Zealand White rabbit is a highly accessible animal model which is regularly employed in biomedical research. However, the paucity of rabbit-specific reagents available limits its use in certain fields. Specifically, the lack of a reliable T cell assay has limited its employment in immune prophylactic and therapeutic studies. To address this inadequacy, we have developed an ELISpot assay to detect cellular immune responses (IFN-γ production) after antigenic stimulation. We have applied this assay to model the T cell responses elicited by a DNA vaccine. Immunization with an influenza nucleoprotein (NP) DNA vaccine revealed strong antigen-specific T cell responses in the peripheral blood mononuclear cell population. We believe this is the first report of such an assay in rabbit species, and it will become a useful tool to monitor in vivo responses to vaccines and permit the wider adoption of this model to measure immunological responses.