Project Grant 20246701542412

** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** OVER 103 MILLION METRIC TONS OF CHICKEN MEAT WAS PRODUCED IN THE WORLD IN 2023, WITH 20% PRODUCED IN THE USA, RANKING POULTRY AS THE SECOND MOST-PRODUCED MEAT IN THE WORLD. AMERICANS ALSO CONSUME THE MOST CHICKEN MEAT IN THE WORLD, DESPITE HAVING A SMALLER POPULATION THAN OTHER COUNTRIES LIKE CHINA OR INDIA. THE COST OF MEAT AND EGG PRODUCTION HAS INCREASED OVER THE YEARS PARTLY DUE TO INCIDENCES OF DISEASES SUCH AS MAREK'S DISEASE. MAREK'S DISEASE IS CAUSED BY A HERPES VIRUS CALLED MAREK'S DISEASE VIRUS (MDV) AND CAUSES CANCER AND OTHER AILMENTS WITHIN THE FIRST FEW WEEKS AFTER HATCHING. THIS ULTIMATELY LEADS TO DECREASED GROWTH OF THE CHICKENS, SUSCEPTIBILITY TO OTHER DISEASES, CONDEMNATION OF THE MEAT AT THE PROCESSING PLANT, AND DEATH, CONTRIBUTING TO THE OVERALL COST OF PRODUCTION. MOST LICENSED VACCINES AGAINST MD ARE ADMINISTERED AS CELL-ASSOCIATED PREPARATIONS, ALSO INCREASING THE COSTS OF PRODUCTION SINCE THESE VACCINES REQUIRE STORAGE AND TRANSPORTATION IN LIQUID NITROGEN AND REQUIRE A SIGNIFICANT AMOUNT OF PRIMARY CELL CULTURE FOR THEIR PRODUCTION. THEREFORE, A CELL-FREE MAREK'S DISEASE VACCINE THAT CAN BE PREPARED AS A STABLE, LYOPHILIZED PREPARATION WOULD GREATLY BENEFIT THE POULTRY INDUSTRY, ESPECIALLY IN COUNTRIES OR RURAL SETTINGS THAT CANNOT AFFORD LIQUID NITROGEN STORAGE FOR CURRENT MD VACCINES. A MAJOR OBSTACLE IN DESIGNING NEW CELL-FREE VACCINES IS THE LACK OF INFORMATION ON VIRAL GENES IMPORTANT FOR THIS ESSENTIAL STEP IN THE VIRUS LIFE CYCLE. WE HAVE IDENTIFIED SPECIFIC VIRUS GENES THAT ARE ESSENTIAL FOR THE TRANSMISSION OF MDV AND THE PRODUCTION OF A CELL-FREE VIRUS TERMED THE CONSERVED HERPESVIRUS PROTEIN KINASE (CHPK). WE HAVE IDENTIFIED MODIFICATIONS OF THIS PROTEIN KINASE DURING INFECTION IN CHICKENS THAT ARE NOT PRESENT DURING REPLICATION IN CELL CULTURE, THE TECHNIQUE USED TO PRODUCE MAREK'S DISEASE VACCINES. OUR GOAL HERE IS TO BETTER UNDERSTAND THESE SPECIFIC MODIFICATIONS OF THE PROTEIN KINASE THAT WE CAN USE TO PRODUCE CELL-FREE MAREK'S DISEASE VACCINES. THE LONG-TERM IMPACT OF THIS WORK IS THE DEVELOPMENT OF NOVEL VACCINES THAT CAN BE USED TO PROVIDE BETTER PROTECTION FOR CHICKENS WITHOUT THE ADDED COST OF MAINTAINING A COLD CHAIN FOR ADMINISTERING THE VACCINE TO POULTRY PRODUCERS.