Intracellular delivery of HA1 subunit antigen through attenuated Salmonella Gallinarum act as a bivalent vaccine against fowl typhoid and low pathogenic H5N3 virus

Abstract

Introduction of novel inactivated oil-emulsion vaccines against different strains of prevailing and emerging low pathogenic avian influenza (LPAI) viruses is not an economically viable option for poultry. Engineering attenuated Salmonella Gallinarum (S. Gallinarum) vaccine delivering H5 LPAI antigens can be employed as a bivalent vaccine against fowl typhoid and LPAI viruses, while still offering economic viability and sero-surveillance capacity. In this study, we developed a JOL1814 bivalent vaccine candidate against LPAI virus infection and fowl typhoid by engineering the attenuated S. Gallinarum to deliver the globular head (HA1) domain of hemagglutinin protein from H5 LPAI virus through pMMP65 constitutive expression plasmid. The important feature of the developed JOL1814 was the delivery of the HA1 antigen to cytosol of peritoneal macrophages. Immunization of chickens with JOL1814 produced significant level of humoral, mucosal, cellular and IL-2, IL-4, IL-17 and IFN-γ cytokine immune response against H5 HA1 and S. Gallinarum antigens in the immunized chickens. Post-challenge, only the JOL1814 immunized chicken showed significantly faster clearance of H5N3 virus in oropharyngeal and cloacal swabs, and 90% survival rate against lethal challenge with a wild type S. Gallinarum. Furthermore, the JOL1814 immunized were differentiated from the H5N3 LPAI virus infected chickens by matrix (M2) gene-specific real-time PCR. In conclusion, the data from the present showed that the JOL1814 can be an effective bivalent vaccine candidate against H5N3 LPAI and fowl typhoid infection in poultry while still offering sero-surveillance property against H5 avian influenza virus.

Immune Evaluation of Recombinant Lactobacillus plantarum With Surface Display of HA1-DCpep in Mice

“…Hajam et al used Salmonella to express the HA1 antigen, which has dual functions as a delivery system and as a natural adjuvant, that could trigger specific humoral and cell-mediated immune responses (29). Kamble et al showed that intracellular delivery of HA1 subunit antigens by attenuated Salmonella protected chickens from infection with a low-pathogenicity H5N3 subtype virus and increased systemic viral clearance (30). Our results in the present study are consistent with those reported in other studies; specifically, recombinant Lactobacillus expressing HA1 can induce specific humoral and cellular immunity, indicating that the HA1 antigen can be used as a target-binding antigen for vector delivery with good immunogenicity.…”

Live poultry vaccines against highly pathogenic avian influenza viruses

“…The immunization of chickens with this vaccine candidate demonstrated the faster clearance of H5N3 challenge virus. This recombinant vaccine can be used as a bivalent preparation against fowl typhoid and influenza diseases [28].…”