Multivalent DNA vaccine expressing the glycoproteins and tegument protein of infectious laryngotracheitis virus elicits robust humoral and cellular immune response in chickens

Abstract

Infectious laryngotracheitis poses a severe threat to chickens causing huge economic loss to poultry industry globally. DNA vaccination is a novel approach to induce protective immunity to infectious diseases. The immunogenicity of multivalent DNA vaccine against ILT virus was evaluated in chicken. Three expression plasmids targeting the glycoproteins and tegument protein of ILTV were constructed. Experimental chickens were immunized either with individual plasmids or as combination of all three plasmids (multivalent). A higher level of ILTV specific antibody response was detected in the chickens immunized with combination of three plasmids. The multivalent immunized group of birds showed augmented T cell response than the monovalent immunized groups. The Th1 type cytokines IFNγ and IL-2 were observed to be significantly upregulated in the multivalent immunization group in comparison with monovalent groups. This study showed clear picture of robust humoral and cellular immune response by multivalent DNA expressing the glycoproteins and tegument protein of ILTV.