Immunization of chickens with Salmonella gallinarium ghosts expressing Salmonella Enteritidis NFliC-FimA(C) and CD40LC fusion antigen enhances cell-mediated immune responses and protects against wild-type challenges with both species

This study describes the construction and immunological characterization of a novel Salmonella gallinarium ghost vaccine to protect against S. gallinarium (SG) and S. Enteritidis (SE) serotypes. The SG ghost was designed to express N-terminus FliC (D0-D1 domain) and FimA retrieved from the SE genome, and the receptor-binding domain (RBD) of CD40L from the chicken as a single fusion construct. The construct was built in pJHL184, a phage lysis gene E -mediated ghost plasmid and the expression was confirmed by western blot resulting in an 85kDa band. Chicken immunization was conducted by intramuscular route with SG ghost FliC-FimA-CD40L, vector control, or PBS alone in a prime-boost schedule. Antibody responses, cell-mediated immune responses (CMI), and cytokine induction was assessed in chicken demonstrating significantly high levels of IgY, CMI, cytokine responses in ghost immunized group delivering partial protection against SG wild type challenge and near complete protection against SE challenge wild type challenge.

Automated summary

This study describes the construction and immunological characterization of a novel Salmonella gallinarium ghost vaccine, providing partial protection against SG wild type challenge and near complete protection against SE challenge. Chicken immunization with the SG ghost showed significantly high levels of IgY, CMI, and cytokine responses, demonstrating the efficacy of this vaccine in enhancing immunity against SG and SE serotypes.