Location: Endemic Poultry Viral Diseases Research
Project Number: 6040-32000-084-008-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2023
End Date: Aug 30, 2027
Objective:
1. To develop data which conclusively proves that we can express a variety of fusion proteins which contain a peptidoglycan binding motif and an antigen of interest (e.g., the avian reovirus sigma C protein). We will also need to demonstrate that fusion proteins which do not contain a secretion signal are accumulated within the cytoplasm of lactic acid bacteria as inclusion bodies.
2. To demonstrate that lactic acid bacteria, when used as antigen presentation platforms, can induce both a localized immune response at the mucosal surface (as evidenced by the production of IgA) and a systemic response (as evidenced by the production of IgY, the avian equivalent of IgG).
Approach:
The chicken mucosal surface (both respiratory and gut) is home to many species of lactic acid bacteria (LABs) in healthy animals under normal circumstances and are beneficial to the host organism. Most animal viruses utilize a mucosal surface as their point of entry into the body making the mucosal immune environment a critical barrier in the establishment and subsequent course of an infection. Mucosal membranes are a complex immunological environment with specialized cells called M (multifold) cells which sample the lumen and transport and degrade bacteria, viruses and macromolecules and pass these processed molecules to antigen presenting cells (APCs) such as macrophages and dendritic cells. For this reason and for many others, LABs that display immunogenic antigens on their surfaces have become attractive options for the induction of both mucosal and systemic immunity. This approach has been well-reviewed and offers great flexibility when designing a system to produce and vector heterologous antigenic proteins. We aim to use this approach to create an economical and efficacious way to immunize chickens against strains of avian reovirus.
