Humoral and Interferon-γ Immune Response to DNA Vaccine En- coding The surface Glycoprotein B of Infectious Laryngotracheitis Virus

DNA vaccines continue to be a suitable safe and potent alternative particularly for controlling the infection with pathogens that rely on the cell-mediated type of immune response and for the ability to eliminate viral shedding Infectious laryngotracheitis virus causes a contagious respiratory disease with a considerable economic impact. The aim of current study was developing of a DNA vaccine coding for the surface glycoprotein B gene (gpB) from locally isolated strain. The developed vaccine (pcDEST40-gpB) could elicit potent antibody titers positively correlated with the commercially available live TC-propagated ILT vaccine. IFN-gamma gene transcript revealed that both DNA vaccine and live vaccine initiate a powerful fold change in IFN-gamma till the 15 days post-vaccination, however, by day 7 post-challenge, the use of a booster dose of DNA vaccine resulted in an abrupt increase in the level of IFN-gamma gene transcript, which was significantly higher than that of the live vaccine. Surprisingly, the data present here revealed that the DNA vaccine, but not the live vaccine, could prevent virus shedding after a challenge.