New vaccination without needle through an outer membrane vesicle

Function of outer membrane vesicles decrypted - New vaccines and treatment approaches possible
The ejected outer skin (outer membrane vesicles) of bacteria could in the future revolutionize the development of vaccines. A research team headed by Professor dr. Stefan Schild from the Institute of Molecular Biosciences at the University of Graz has decoded the origin and function of the outer membrane vesicles, opening up new approaches to vaccine development. Several years ago, the scientists headed by Prof. Schild applied for the patent for non-needle vaccinations based on the outer membrane vesicles. Now they have come a significant step further.

Low-cost, easy-to-use, needle-free vaccinations are the goal of the researchers led by Professor Stefan Schild from the Institute of Molecular Biosciences. Their patented process relies on immunization through outer membrane vesicles. These are rejected outer skins of very specific bacteria - including the causative agents of cholera and severe respiratory diseases. Humans are developing antibodies in response to the outer membrane vesicles, according to researchers. Schild and colleagues published their findings in the journal Nature Communications.

The outer membrane vesicles could help not only in the development of vaccines but also in the treatment of diseases. (Image: Alexander Raths / fotolia.com)

Origin and function of the outer membrane vesicles explained
The Graz scientists, in collaboration with US researchers at the University of Alberta, have now succeeded for the first time in deciphering the mechanism of formation and functioning of the outer membrane vesicles, according to the Communication of the Institute of Molecular Biosciences at the University of Graz. The results help to improve the production of the vaccine candidate and "in addition, we have discovered a new treatment option for the diseases", emphasize the bioscientists. Because bacteria also release toxins and other substances into the human organism with the help of the outer membrane vesicles, which have a significant influence on the course of the disease. Intervention in the mechanism of the outer membrane vesicles could possibly prevent this.

Transporter of the bacteria
According to the researchers, "all Gram-negative bacteria, which include many pathogens, have a so-called lipid transporter, which transports fat components of the outer membrane back into the interior of the microorganism." Iron act as a kind of "switch" for this system. If there is not enough iron, the transporter is stopped. This has the consequence that fats accumulate in the bacterial envelope so much that bulges of the envelope arise. "After all, the outer skin splits off globally and also carries poisons into the host that trigger the disease," explains Professor Schild.

New approach to treating bacterial infections
The scientists emphasize that they are just beginning to understand the role of the outer membrane vesicles. In summary, it can be stated that they can remove and supply substances for the bacteria. For the first time it becomes clear why many bacterial pathogens pack ill poisons into these globules. Because the microorganisms in the human body never get enough iron, a great many harmful to the host outer membrane vesicles are rapidly produced, explain Professor Schild and colleagues. The current findings not only help to control the amount of outer membrane vesicles and thus of the vaccine, but also a rapid treatment can be made possible with already developed diseases by a new therapeutic approach, the researchers continue. "If one intervenes in this transport system of microorganisms and stops the splitting off of the vesicles, one could for example prevent the emission of toxins", emphasizes Professor Schild. (Fp)