Summary

Infectious Laryngotracheitis Virus (ILTV) is currently causing significant commercial burden to the Australian poultry industry. Emergence of more virulent strains of ILTV from the recombination of attenuated vaccine strains has added significant pressure to the control of this devastating disease. We have developed a safe and effective ILTV vaccine which offers possible control mechanism for ILTV, however, production of our modified ILTV vaccine relies on the use of eggs, in particular the chorioallantoic membrane (CAM), to amplify the vaccine. This process involving eggs is extremely low yield, expensive and time consuming, leading to a shortfall in vaccine supply and uptake for Australian farmers.
In this project we will develop a cell line substrate with enhanced ILTV growth properties to allow production of this vital ILTV vaccine without the reliance on the costly egg production method. We will develop an immortalise cell line from primary CAM cells suitable for vaccine production. Then, using a newly developed technique – genome-wide CRISPR Knock Out (GeCKO), we will identify and remove key antiviral (ILTV specific) genes from this cell line to develop a new enhanced vaccine growth cell line that can deliver cost effective ILTV vaccine to the Australian poultry industry.
To achieve this we will:
(i) Determine the ideal CAM cell type to immortalise and remove the cell replication blockade
(ii) Identify and remove key inhibitors of ILTV vaccine production within the cells
(iii) Assess the growth of our safe and effective vaccine in the laboratory and commercial setting

Program

Chicken Meat

Research Organisation

Commonwealth Scientific and Industrial Research Organisation (CSIRO)

Objective Summary

In this project the aim is to deliver to the market a cost effective solution to ILT vaccination. This will be achieved by assessing the safe and effective ILT vaccine for in ovo and spray use and by developing a new sterile cell substrate on which to grow the vaccine.
Specifically, the objectives are:
– Objective 1: Determination of primary cell substrate – This objective will be completely conducted by CSIRO
­- Objective 2: Immortalise chicken cells for ILTV growth – This objective will be completely conducted by CSIRO
­- Objective 3: Optimisation Phase 1 – Screen for antiviral ILTV genes – This objective will be completely conducted by CSIRO;
­- Objective 4: Optimisation Phase 2 – generate a stable optimised vaccine producing cell – This objective will be completely conducted by CSIRO;
­- Objective 5: Commercial growth assessment – This objective will be primarily conducted by Bioproperties; and
­- Objective 6: Assess the safety and efficacy of the Vaxsafe ILT vaccine grown in new cell line – This objective will be primarily conducted by University of Melbourne.