Study On The Immune Efficacy Of Recombinat Fowlpox Virus Expressing The Major Antigen Epitope Genes Of Glycoprotein B And D Of Infectious Laryngotracheitis Virus And The Constant Region Genes Of Heavy Chain Of Chicken IgY

Infectious laryngotractheitis (ILT) is an important upper respiratory tract infection of chickens characterized by signs of respiratory depression, gasping, expectoration of bloody mucus, and high mortality. The disease is found worldwide and may result in severe production losses and reduced egg production. It was classified type B infectious disease by OIE. The causative agent of the disease is an alphaherpesvirus, infectious laryngotracheitis virus (ILTV) that was classified as gallid herpesvirus 1. ILT was also found in our country on the 60's and occurred in many provinces and cities one after another. Present vaccines for ILT are all conventionally attenuated live vaccines. As immunogenicity of ILTV is usually correlated with its virulence, almost all applied vaccines remained moderately pathogenic and have shown a variety of side effects including spread of vaccine virus to nonvaccinates, occurrence of long term "carrier"' birds, increasing virulence during in vivo passage, and can't differentiate the vaccine strain and the field strain. With the development of molecular biology, preventing and eliminating ILT with genetic vaccine is the prefered method. Fowl poxvirus vector is a new animal virus vector developed after vaccinia virus vector and has many advantages. Firstly, fowl poxvirus only infects poultry and has a miscarried infection to other animal, but can induce protective immune reaction. Secondly, fowl poxvirus has a large double-stranded DNA with some separate non-essential genomic regions suitable for foreign gene insertion. Thirdly, as fowl poxvirus can be multiplicated in chicken embryo fiber cell easily. the recombinant fowl poxvirus vaccine is able to be produced industrially. At the present time. many protective antigen genes of poultry and animal virus have been expressed with fowl poxvirus vector successfully and some of them can induce protective immunity after being vaccinated animal. In this report, we constructed the recombinant fowl poxvirus expressing the major antigen epitope genes of...