Bacterial Membrane Vesicles as Versatile Platforms for Systemic and Mucosal Vaccines.

Area of Science:

• Microbiology and Immunology
• Vaccinology
• Nanotechnology

Background:

• Conventional vaccines face limitations like antigenic variation and reliance on limited adjuvants.
• Bacterial membrane vesicles (BMVs), including outer membrane vesicles (OMVs) and extracellular vesicles (EVs), offer intrinsic immunostimulatory properties.
• BMVs act as self-adjuvanting systems, delivering antigens while activating innate immune responses.

Purpose of the Study:

• To review the biological features and immunological mechanisms of BMVs as vaccine platforms.
• To highlight the potential of BMVs in combating bacterial, fungal, and viral infections.
• To discuss challenges and future directions for BMV-based vaccine development.

Main Methods:

• Literature review summarizing studies on BMVs in vaccine development.
• Analysis of BMV composition, including pathogen-associated molecular patterns (PAMPs).
• Examination of immune responses induced by BMVs, including innate and adaptive immunity.

Main Results:

• BMVs are nanoscale lipid bilayers that activate pattern recognition receptors on antigen-presenting cells.
• BMVs induce pro-inflammatory cytokines, type I interferons, and adaptive immunity (antibody production, Th1/Th17 responses).
• BMVs have demonstrated efficacy in preclinical models against bacterial, fungal, and viral pathogens, enhancing both systemic and mucosal immunity.

Conclusions:

• BMVs represent a versatile and promising vaccine platform due to their self-adjuvanting nature and antigen-delivery capabilities.
• Further research is needed to address standardization, safety, and antigen-loading efficiency for clinical translation.
• Engineered BMVs hold potential for improved antigen presentation and T cell responses, advancing vaccine technology.