Abstract:
High-quality vaccines are crucial to prevent infectious disease outbreaks in the poultry
industry. In vivo vaccination tests are routinely used to test poultry vaccines for their potency,
i.e., their capacity to induce protection against the targeted diseases. A better understanding of how
poultry vaccines activate immune cells will facilitate the replacement of in vivo potency tests for
in vitro assays. Using the chicken macrophage-like HD11 cell line as a model to evaluate innate
immune responses, the current explorative study addresses the immunostimulatory capacity of an
inactivated multivalent vaccine for infectious bronchitis, Newcastle disease, egg-drop syndrome,
and infectious coryza. The vaccine stimulated HD11 cells to produce nitric oxide and to express
pro-inflammatory cytokines IL-1 , TNF, and IL-12p40, chemokines CXCLi1 and CXCLi2, and the
anti-inflammatory cytokine IL-10, but only when inactivated Avibacterium paragallinarum, the causative
agent of infectious coryza, was present. Lipopolysaccharides from Avibacterium paragallinarum were
crucial for the production of nitric oxide and expression of IL-1 and CXCLi1. The described immune
parameters demonstrate the capacity of this multivalent vaccine to activate innate immune cells
and may in the future, combined with antigen quantification methods, contribute to vaccine quality
testing in vitro, hence the replacement of current in vivo vaccination tests.
Description:
Figure S1: Cytotoxicity of the octavalent vaccine, extracted antigens and purified Av. paragallinarum bacteria,
Figure S2: Gram staining of extracted antigens from the tri- and octavalent vaccines, Figure S3: The octavalent
vaccine-induced gene expression of IL-10, whereas a trivalent vaccine without Av. paragallinarum antigens did not.
