In Europe, vaccines typically use adjuvants to stimulate a better reaction, but these are designed to trigger an immune response at the site where the shot is injected. A team of researchers at Duke University Medical Center have designed targeted nanoparticles that may boost vaccine responses even further by triggering a response at the lymph nodes.
The team has created synthetic nanoparticles that model the granules in mast cells, a type of white blood cell involved in inflammation and allergic responses. These granules include inflammatory mediators--such as the tumor necrosis factor (TNF)--and are preferentially taken up by the lymph nodes. The design of the nanoparticles, which are made up of a carbohydrate backbone surrounding TNF, means they are also taken up by the lymph nodes, where the mediators are released and the immune response is triggered, stimulating B-cell lymphocytes. Incorporating IL-12 stimulated a response from a different set of immune cells, the Th1 lymphocytes.
"Our strategy is unique because we have based our bioengineered particles on those naturally produced by mast cells, which effectively solve the same problem we are trying to solve of combating infection," said lead author Ashley St. John.
The synthetic particles have also been used in mice with influenza A, and the researchers saw an effective immune response at levels of flu virus that would normally be lethal.
Because the use of different inflammatory mediators triggers a response from different cells in the immune system, the researchers believe that these nanoparticles could lead to the development of personalized vaccines. As the different 'ingredients' of the nanoparticles are already FDA-approved for human use, this could expedite the development of this new adjuvant.