Effector cell-mediated immune response in mice immunised with Salmonella

Area of Science:

• Immunology
• Microbiology
• Vaccinology

Background:

• Cell-mediated immunity is crucial for controlling intracellular pathogens like Salmonella.
• Different vaccine formulations can elicit distinct immune responses.

Purpose of the Study:

• To compare the effector responses of cell-mediated immunity induced by live and formalized Salmonella vaccines.
• To assess the persistence of immune responses at immediate and 3-month time points.

Main Methods:

• Mice were immunized with live or formalized Salmonella enteritidis vaccines.
• Immune responses, including delayed hypersensitivity and macrophage activation, were measured.
• Re-stimulation with specific Salmonella antigens was performed.

Main Results:

• Live S. enteritidis vaccination induced delayed hypersensitivity and activated macrophages.
• Formalized vaccine failed to induce these responses.
• Activated macrophages decreased by 3 months, but delayed hypersensitivity persisted.
• Re-stimulation elicited responses in previously vaccinated mice.

Conclusions:

• Live Salmonella vaccines are more effective in generating robust cell-mediated immunity compared to formalized vaccines.
• Delayed hypersensitivity is a more persistent immune marker than macrophage activation post-vaccination.
• Cell-mediated immunity can be recalled by homologous and heterologous Salmonella antigens.