[Advances in outer membrane vesicles of gram-negative bacteria as sub-unit vaccines - A review].

Outer membrane vesicles (OMVs) are vesicle-like structures, widely present in gram-negative bacteria and even in some gram-positive bacteria. OMVs contain biological active substances and their sizes are normally between 20 to 250 nm. Components of OMVs include lipopolysaccharide, outer membrane protein, phospholipids, DNA, as well as the periplasmic components produced during their formation. OMVs are non-viable vesicles that contain multiple antigenic proteins from the bacterial outer membrane, and are capable of activating the immune system, therefore they are considered to be potential vaccine candidates. Although outer membrane vesicles were discoverd more than 50 years ago, hardly any reports were published in China. In this review, we summarized the progress of outer membrane vesicles as a novel strategy for disease prevention and control in two aspects: the mechanism of the outer membrane vesicle-induced immune response and the advances in OMVs vaccine. This review provides some information on outer membrane vesicles as vaccine development.