Brucella abortus antigen omp25 vaccines: Development and targeting based on Lactococcus lactis

Area of Science:

• Immunology
• Microbiology
• Vaccine Development

Background:

• Brucella infections primarily occur at mucosal membranes, necessitating effective mucosal vaccination strategies.
• Developing oral vaccines is crucial for managing brucellosis, a widespread zoonotic disease.

Purpose of the Study:

• To assess the efficacy of a recombinant oral antigen delivery system using Lactococcus lactis for the Brucella abortus omp25 antigen.
• To evaluate the immunogenicity and protective potential of this novel oral vaccine in a mouse model.

Main Methods:

• Lactococcus lactis was engineered to express the Brucella abortus omp25 antigen.
• Mice were immunized orally with the engineered L. lactis, and immune responses (IgG1, sIgA, cytokines) were analyzed.
• Protective efficacy was evaluated by challenging vaccinated mice with Brucella abortus.

Main Results:

• Oral vaccination with L. lactis expressing omp25 induced significant omp25-specific IgG1 and sIgA antibody responses.
• Vaccination led to increased levels of key cytokines (IFN-γ, TNF-α, IL-4, IL-10) and reduced inflammatory damage in spleen and lung tissues.
• Mice vaccinated with the L. lactis system demonstrated protection against Brucella abortus challenge.

Conclusions:

• Lactococcus lactis serves as an effective and safe oral delivery system for the Brucella abortus omp25 antigen.
• This novel approach offers a cost-effective, sustainable, and simple method for developing new vaccines against brucellosis.