Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2002
Publication Date: N/A
This study was conducted to investigate the differential impact of live and killed Salmonella enteritidis (SE) vaccines on cell-mediated immunity of 16 and 32 week old White Leghorn hens. The hens were vaccinated with the 2 vaccines and two weeks later CMI was assessed using splenic mononuclear cell proliferation, in response to Con A and antigen and cell subpopulation numbers as indices. Mitogen and SE flagella mediated proliferation and the cell populations were determined by 3H-thymidine uptake and flow cytometry, respectively. Con-A mediated and the SE flagella mediated proliferation were enhanced in the 16 week old and 32 week old birds vaccinated with live vaccine, compared to the corresponding control birds. However, Con A-mediated response was higher in the killed vaccine group of only the 16-week old birds compared to the corresponding control birds. Furthermore, there was a significant increase in the SE-flagella mediated proliferation in the killed vaccine group compared to the control group in case of 32-week old birds. These functional changes were accompanied by some changes in the splenic mononuclear cell subpopulations, which included increased CD4 population in the live vaccine group compared to the control and the killed vaccine groups. Correspondingly, there was a reduction in the CD8 population in the live vaccine group, compared to the killed vaccine group. Overall, live vaccine appeared to result in greater functional changes, such as non-specific mitogen and antigen-specific proliferation of splenic lymphocytes compared to the killed vaccine. This may prove beneficial in protecting hens that are infected with the wild type SE.