How to increase the effectiveness of DNA vaccines

One of the areas of work to improve the effectiveness of vaccination against infectious diseases is the creation of DNA vaccines. The essence of the approach is to inject the patient with DNA encoding a protein that stimulates the development of an immune response.

Currently existing DNA vaccines induce a relatively weak immune response even with repeated administration. In experiments on mice, scientists at Rockefeller University, working under the guidance of Dr. Ralph Steinman, demonstrated a way to increase the effectiveness of such vaccines.

As part of the experiments, animals were injected with a DNA vaccine encoding protein synthesis, which is a combination of the HIV gp41 protein and a single-stranded antibody (single-stranded antibodies, or Fv fragments, are polypeptides consisting of a variable region of the heavy chain of the antibody associated with a variable region of the light chain), specific to the molecule DEC205. DEC205 is expressed by dendritic cells, which process proteins of pathogenic microorganisms and present them to T-lymphocytes, which subsequently selectively destroy pathogens.

Due to the fact that DEC205-specific Fv fragments provide selective delivery of viral protein to dendritic cells, such a vaccine induced a much more pronounced immune response than control variants of DNA vaccines containing combinations of gp41 protein with other antibodies, and more effectively protected mice from a genetically modified virus expressing the gp41 HIV protein.

The data obtained indicate that the effectiveness of DNA vaccines can be significantly improved by introducing into it a DNA fragment encoding a protein specific to dendritic cells, for example, an antibody to any of the surface markers of these cells.

Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily

12.03.2008