tetano
Editor, Senior Moderator
Avian Pathol
. 2020 Jun 2;1-38.
doi: 10.1080/03079457.2020.1775782. Online ahead of print.
Oral Immunization With an Attenuated Salmonella Gallinarum Encoding the H9N2 Hemagglutinin and M2 Ectodomain Induces Protective Immune Responses Against H9N2 Infection in Chickens
Irshad Ahmed Hajam[SUP] 1 [/SUP], Perumalraja Kirthika[SUP] 1 [/SUP], Chamith Hewawaduge[SUP] 1 [/SUP], Vijayakumar Jawalagatti[SUP] 1 [/SUP], Sung Woo Park[SUP] 1 [/SUP], Amal Senevirathne[SUP] 1 [/SUP], John Hwa Lee[SUP] 1 [/SUP]
Affiliations
Abstract
H9N2, a low pathogenic avian influenza (LPAI) virus, causes significant economic losses in the poultry industry worldwide. Herein, we describe the construction of an attenuated Salmonella Gallinarum (SG) strain for expression and delivery of H9N2 hemagglutinin (HA) 1 (SG-HA1), HA2 (SG-HA2) and/or the conserved matrix protein 2 ectodomain (SG-M2e). We demonstrated that recombinant SG strains expressing HA1, HA2 and M2e antigens were immunogenic and safe in a chicken model. Chickens (N=8) were vaccinated once orally with SG alone, SG-HA1, SG-HA2, SG-M2e, or mixture of SG-HA1, SG-HA2 and SG-M2e, or vaccinated once intramuscularly with an oil-adjuvant inactivated H9N2 vaccine. Our results demonstrated that vaccination with SG mutants encoding influenza antigens, administered individually or as a mixture, elicited significantly (p<0.05) greater antigen-specific humoral and cell-mediated immune responses in chickens compared those vaccinated with SG alone. A conventional H9N2 vaccine induced significantly (p<0.05) greater HA1 and HA2 antibody responses than SG-based H9N2 vaccine strains, but significantly (p<0.05) less robust M2e-specific responses. Upon challenge with the virulent H9N2 virus on Day 28 post-vaccination, chickens vaccinated with either the SG-based H9N2 or conventional H9N2 vaccines exhibited comparable lung inflammation and viral loads, although both were significantly lower (p<0.05) than in the group vaccinated with SG alone. In conclusion, our results showed that SG-based vaccination stimulated efficient immune responses against virulent H9N2. Further studies are needed to fully develop this approach as a preventive strategy for LPAI viruses affecting poultry.
Keywords: Salmonella Gallinarum; H9N2 virus; delivery system; matrix protein 2 ectodomain; prophylaxis; vaccine.
. 2020 Jun 2;1-38.
doi: 10.1080/03079457.2020.1775782. Online ahead of print.
Oral Immunization With an Attenuated Salmonella Gallinarum Encoding the H9N2 Hemagglutinin and M2 Ectodomain Induces Protective Immune Responses Against H9N2 Infection in Chickens
Irshad Ahmed Hajam[SUP] 1 [/SUP], Perumalraja Kirthika[SUP] 1 [/SUP], Chamith Hewawaduge[SUP] 1 [/SUP], Vijayakumar Jawalagatti[SUP] 1 [/SUP], Sung Woo Park[SUP] 1 [/SUP], Amal Senevirathne[SUP] 1 [/SUP], John Hwa Lee[SUP] 1 [/SUP]
Affiliations
- PMID: 32483989
- DOI: 10.1080/03079457.2020.1775782
Abstract
H9N2, a low pathogenic avian influenza (LPAI) virus, causes significant economic losses in the poultry industry worldwide. Herein, we describe the construction of an attenuated Salmonella Gallinarum (SG) strain for expression and delivery of H9N2 hemagglutinin (HA) 1 (SG-HA1), HA2 (SG-HA2) and/or the conserved matrix protein 2 ectodomain (SG-M2e). We demonstrated that recombinant SG strains expressing HA1, HA2 and M2e antigens were immunogenic and safe in a chicken model. Chickens (N=8) were vaccinated once orally with SG alone, SG-HA1, SG-HA2, SG-M2e, or mixture of SG-HA1, SG-HA2 and SG-M2e, or vaccinated once intramuscularly with an oil-adjuvant inactivated H9N2 vaccine. Our results demonstrated that vaccination with SG mutants encoding influenza antigens, administered individually or as a mixture, elicited significantly (p<0.05) greater antigen-specific humoral and cell-mediated immune responses in chickens compared those vaccinated with SG alone. A conventional H9N2 vaccine induced significantly (p<0.05) greater HA1 and HA2 antibody responses than SG-based H9N2 vaccine strains, but significantly (p<0.05) less robust M2e-specific responses. Upon challenge with the virulent H9N2 virus on Day 28 post-vaccination, chickens vaccinated with either the SG-based H9N2 or conventional H9N2 vaccines exhibited comparable lung inflammation and viral loads, although both were significantly lower (p<0.05) than in the group vaccinated with SG alone. In conclusion, our results showed that SG-based vaccination stimulated efficient immune responses against virulent H9N2. Further studies are needed to fully develop this approach as a preventive strategy for LPAI viruses affecting poultry.
Keywords: Salmonella Gallinarum; H9N2 virus; delivery system; matrix protein 2 ectodomain; prophylaxis; vaccine.