Protective efficacy and immune responses by homologous prime-booster immunizations of a novel inactivated Salmonella Gallinarum vaccine candidate.
10.7774/cevr.2016.5.2.148
- Author:
Gayeon WON
1
;
Atul A CHAUDHARI
;
John Hwa LEE
Author Information
1. College of Veterinary Medicine, Chonbuk National University, Iksan, Korea. johnhlee@jbnu.ac.kr
- Publication Type:Original Article
- Keywords:
Salmonella;
Ghost vaccine;
Immunization scheme;
Protection;
Fowl typhoid
- MeSH:
Birds;
Chickens;
Cytokines;
Immunization*;
Immunoglobulin A, Secretory;
Immunoglobulin G;
Interferons;
Interleukin-6;
Lymphocyte Activation;
Plasma;
RNA, Messenger;
Salmonella enterica;
Salmonella*;
Serogroup;
Spleen;
T-Lymphocytes;
Typhoid Fever;
Vaccination
- From:Clinical and Experimental Vaccine Research
2016;5(2):148-158
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: Salmonella enterica serovar Gallinarum (SG) ghost vaccine candidate was recently constructed. In this study, we evaluated various prime-boost vaccination strategies using the candidate strain to optimize immunity and protection efficacy against fowl typhoid. MATERIALS AND METHODS: The chickens were divided into five groups designated as group A (non-immunized control), group B (orally primed and boosted), group C (primed orally and boosted intramuscularly), group D (primed and boosted intramuscularly), and group E (primed intramuscularly and boosted orally). The chickens were primed with the SG ghost at 7 days of age and were subsequently boosted at the fifth week of age. Post-immunization, the plasma IgG and intestinal secretory IgA (sIgA) levels, and the SG antigen-specific lymphocyte stimulation were monitored at weekly interval and the birds were subsequently challenged with a virulent SG strain at the third week post-second immunization. RESULTS: Chickens in group D showed an optimized protection with significantly increased plasma IgG, sIgA, and lymphocyte stimulation response compared to all groups. The presence of CD4+ and CD8+ T cells and monocyte/macrophage (M/M) in the spleen, and splenic expression of cytokines such as interferon γ (IFN-γ) and interleukin 6 (IL-6) in the immunized chickens were investigated. The prime immunization induced significantly higher splenic M/M population and mRNA levels of IFN-γ whereas the booster showed increases of splenic CD4+ and CD8+ T-cell population and IL-6 cytokine in mRNA levels. CONCLUSION: Our results indicate that the prime immunization with the SG ghost vaccine induced Th1 type immune response and the booster elicited both Th1- and Th2-related immune responses.
