Outer membrane vesicles from group B Neisseria meningitidis delta gna33 mutant: proteomic and immunological...

Area of Science:

• Microbiology
• Vaccinology
• Proteomics

Background:

• Neisseria meningitidis group B (MenB) outer membrane vesicles (OMVs) are crucial vaccine components.
• Understanding OMV composition is key to developing effective vaccines.
• Current methods for OMV isolation may affect their protein content.

Purpose of the Study:

• To compare the proteomes of detergent-derived OMVs (DOMVs) and spontaneously released OMVs (m-OMVs) from MenB.
• To evaluate the immunogenicity and protective capacity of m-OMVs.
• To explore the potential of genetic mutations for generating OMV-releasing phenotypes for vaccine development.

Main Methods:

• Proteomic analysis using 1D and 2D electrophoresis (1- and 2-DE) coupled with mass spectrometry (MS).
• Bioinformatic classification of identified proteins using PSORT.
• Assessment of bactericidal antibody elicitation in vitro against a panel of MenB strains.

Main Results:

• 138 proteins identified in DOMVs, with 64% from inner membrane and cytoplasmic compartments.
• 60 proteins identified in m-OMVs, predominantly classified as outer membrane proteins.
• m-OMVs elicited broad bactericidal activity against diverse MenB strains.

Conclusions:

• Spontaneously released OMVs (m-OMVs) possess a proteome more representative of the bacterial outer membrane compared to DOMVs.
• m-OMVs demonstrate significant potential for broad-spectrum MenB vaccine formulation.
• Identifying mutations that induce OMV release is a promising strategy for studying bacterial membranes and designing novel vaccines.