Abstract: Nasally delivered chitosan-coated poly(lactide-co-glycolide) encapsulating honeybee venom enhances T helper 1–related immunity against Salmonella Typhimurium infection in pigs
OBJECTIVE
Salmonella Typhimurium is a significant zoonotic concern for human food poisoning and a substantial economic burden in the swine industry. We previously reported that nasally delivered chitosan-coated poly(lactide-co-glycolide) (PLGA) encapsulating honeybee venom (CP-HBV) could enhance CD4+ T helper 1 (Th1)-related immune responses in healthy pigs. Building upon these findings, the current study aimed to investigate the protective immune enhancement by nasally delivered CP-HBV in pigs challenged with S Typhimurium.
ANIMALS
36 healthy, 4-week-old, female, Landrace X Yorkshire X Duroc pigs.
METHODS
36 pigs were allocated into 3 groups: CP-HBV (n = 16), control (n = 16), and healthy baseline control (n = 4). CP-HBV and control groups were challenged with S Typhimurium 7 days post-treatment. Pigs from the healthy control group were sacrificed at 0 days postinfection (DPI), and 4 pigs from each of the control and CP-HBV groups were sacrificed at 1, 2, 4, and 7 DPI. Salmonella shedding, immune cell frequencies, cytokines, and transcriptional factor expression levels were measured.
RESULTS
The CP-HBV group exhibited lower bacterial shedding and an enhanced Th1-related immune response characterized by an upregulation of CD4+ T cells and CD4+ Interferon-γ+ T cells, accompanied by increased expression of Th1-related cytokines and reduced expression of regulatory T cells and immunosuppressive cytokines compared to the control group.
CLINICAL RELEVANCE
CP-HBV is a promising strategy for controlling Salmonella infections in pigs and improving public health.
Lee, J., Jung, B., & Lee, B. (2024). Nasally delivered chitosan-coated poly(lactide-co-glycolide) encapsulating honeybee venom enhances T helper 1–related immunity against Salmonella Typhimurium infection in pigs. American Journal of Veterinary Research (published online ahead of print 2024). Retrieved Jul 23, 2024, from https://doi.org/10.2460/ajvr.24.03.0086