Performing Department
(N/A)
Non Technical Summary
According to the 2021 US agriculture statistics, the combined value of production and sales from broilers, eggs, turkeys, and chicks was $46.1 billion. Unfortunately, available vaccines do not provide sufficient protection against emerging and transboundary infections such as Highly Pathogenic Avian Influenza (HPAI) that impacted the poultry industry earlier in 2022. We hypothesize that DNA-based nanoparticle vaccines (nanovaccines) will improve efficiency and delivery of antigens for robust induction of protective immunity against poultry pathogens. Recently, reports from our group indicated that a novel nanoadjuvant system (termed QAC for Quil-A-treated Chitosan) combined with plasmid DNA constructs were able to deliver viral antigens and mount a strong, protective immunity in chickens against Infectious Bronchitis Virus (IBV). In this project, we will capitalize on our experience in developing mosaic nanovaccines that can represent thousands of circulating viral isolates. Specifically, we plan to: First, examine the delivery and stability of avian influenza-hemagglutinin (HA) antigen. We will utilize vaccine constructs to characterize mosaic antigen release kinetics and infectivity to chicken cells following different temperature conditions that mimic field application. Second, we will analyze the immunogenicity of several vaccine constructs in chickens using intranasal and oral routes. Finally, we will analyze the overal vaccine protection by following challenge with LPAI and HPAI. Overall, developing effective, safe, and easy to administer nanovaccines will significantly improve our preparation to control emerging and re-emerging infections in poultry and other animals.
Animal Health Component
50%
Research Effort Categories
Basic
25%
Applied
50%
Developmental
25%
Goals / Objectives
The major goal of this project is to develop effective, safe and easy to administer broad-spectrum vaccines against avian influenza. Those vaccines will significantly improve our preparation to control emerging and re-emerging infections, a goal that is supported by the Agricultural Biosecurity Program. In addition, gained knowledge will help in designing better vaccines against all animal respiraotry infections, aiming to provide a sustained food supply in the USA and worldwide, an important aim shared with NIFA-USDA.
Project Methods
In the first objctive (Obj) of the project, fluorescent labeling of the plasmid vaccines will further enhance our ability to track their persistence and distribution in tissues. We will evaluate the in vitro prolonged release of plasmid DNA from QAC for up to 28 days, a suitable time frame to elicit robust immune responses following immunization in broiler (sent to market around 35-42 days of age). Released plasmids will be further tested for their ability to express mosaic HA proteins once transfected to Chicken Embryo Fibroblasts (CEF), as a test for their ability to express protein following immunization. Further, the shelf-life stability of the QAC nanovaccine will be evaluated at different storage temperatures including -20°C, 4°C and various administration temperatures including 25°C and 37°C to mimic field conditions. We will also begin our safety analysis by examining their toxicity in chicken cells (e.g., lung and epithelial cells) that will most likely meet the vaccine during immunization.In Obj. 2 of this project, vaccines will be administered via the oculo-nasal route to ensure individual animal immunizations that yield itself for further translation to mass application via spray or oral routes under field conditions. Our analysis of the generated immune responses will include the evaluation of both humoral and cellular immunity responsible for protection against AI infection.In Obj. 3 of this project, will further decipher the protective immunity of our novel vaccine constructs following immunization and challenge of birds, a key parameter measured before considering any vaccine for further development. For the challenge with HPAI and LPAI, we selected widely prevalent H5Nx genotypes (clade 2.3.4.4.) homologous to the viruses present US and worldwide (e.g. H5N8, H5N1 and H5N2, H5N3, respectively).