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

Document Type : Original Article


1 biotechnology department,1Central Laboratory for Evaluation of Veterinary Biologics (CLEVB), Agricultural Research Center {ARC}, Cairo, Egypt

2 Central Laboratory for Evaluation of Veterinary Biologics (CLEVB), Agricultural Research Center {ARC}, Cairo.)


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. DNA vaccine was developed 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. Cell-mediated immune response (as measured by quantitation of the IFN-γ gene transcript ), revealed that both DNA vaccine and live vaccine initiate a powerful fold change in IFN-γ till the 15 days post-vaccination, however, the use of booster dose of DNA vaccine resulted in an abrupt increase in the level of IFN-γ transcript which was significantly higher than that of the live vaccine by day 7 post-challenge and onward. DNA vaccine but not the live vaccine could eliminate the shedding of the virus post-challenge.


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