Respiratory syncytial virus (RSV) is a common cause of bronchiolitis and pneumonia in young children as well as older adults, yet after decades of research no effective vaccine has been developed. Attenuated vaccines don’t work well because RSV has two antigenically different groups producing different antibodies, and immune systems of very young children don’t respond sufficiently to some vaccines.
Now researchers at Vanderbilt University have taken a completely different approach, using gold nanorods to ferry a protein that allows the virus to enter the interior of cells. By introducing the so called F protein to immune cells ahead of infection, the vaccination system prepares them for a real infection. The nanorods are in shape and size very similar to the actual respiratory syncytial virus and were coated with the F protein. These compounds were introduced into samples of dendritic cells taken from adult donors and showed that T cells, a sign of an immune response, multiplied with gusto.
From the Institute of Physics:
Dendritic cells function as processing cells in the immune system, taking the important information from a virus, such as the F protein, and presenting it to cells that can perform an action against them―the T cells are just one example of a cell that can take action.
Once the F protein-coated nanorods were added to a sample of dendritic cells, the researchers analysed the proliferation of T cells as a proxy for an immune response. They found that the protein-coated nanorods caused the T cells to proliferate significantly more compared to non-coated nanorods and just the F protein alone.
Not only did this prove that the coated-nanorods were capable of mimicking the virus and stimulating an immune response, it also showed that they were not toxic to human cells, offering significant safety advantages and increasing their potential as a real-life human vaccine.
Lead author of the study, Professor James Crowe, said: “A vaccine for RSV, which is the major cause of viral pneumonia in children, is sorely needed. This study shows that we have developed methods for putting RSV F protein into exceptionally small particles and presenting it to immune cells in a format that physically mimics the virus. Furthermore, the particles themselves are not infectious.”
Due to the versatility of the gold nanorods, Professor Crowe believes that their potential use is not limited to RSV.
“This platform could be used to develop experimental vaccines for virtually any virus, and in fact other larger microbes such as bacteria and fungi.
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