Nanoparticle-based vaccine effective in preclinical trials


The circle-shaped objects in the image above are cobalt-porphyrin-phospholipid (CoPoP) nanoparticles decorated with flu proteins. Credit: University at Buffalo.

An experimental flu vaccine consisting of billions of small spherical sacs that carry proteins against the infection throughout the body has been shown to be effective in preclinical studies.

Described in a study published May 24 by Proceedings of the National Academy of Sciences, the vaccine has the potential to:

  • Improve the effectiveness of seasonal flu vaccines, which typically work 40 to 60 percent of the time, according to the U.S. Centers for Disease Control and Prevention.
  • It takes less time to produce large amounts because, unlike most seasonal flu vaccines, it is not created in embryonated chicken eggs.
  • Use smaller doses, thus increasing the supply of vaccines, which can be critical given the unpredictable nature of the flu.

“The results are very encouraging,” says the study’s lead author, Jonathan Lovell, Ph.D., associate professor of biomedical engineering at the University at Buffalo.

“Typically, flu vaccines contain inactivated microbes that cause the flu, or are based on weakened forms of the disease. The vaccine we develop is recombinant. nanoparticle vaccine that stimulates a strong “, Says Lovell.

The key to the vaccine’s success is a liposome created by Lovell and colleagues called cobalt-porphyrin-phospholipid or CoPoP.

These small spherical sacs, small enough to be considered nanoparticles, form the backbone of what is known as the pharmaceutical language as a vaccine platform, which is any underlying technology used to develop multiple vaccines.

(Although not part of this study, the platform is used in clinical trials in South Korea as a candidate for the COVID-19 vaccine. It is a partnership between the derivative company UB POP Biotechnologies, co-founded by Lovell, and South Korean biotechnology company EuBiologics POP Biotechnologies is also working with Scripps Research to study the platform for a possible HIV vaccine.)

Alone, these liposomes do not fight disease. But they have a special talent. They spontaneously convert virus proteins that elicit immune responses to a more potent nanoparticle format.

“This conversion is advantageous because the dissolved proteins bind to the surface of the liposomes, where the proteins improve The response to disease, “says lead author Matthew Miller, Ph.D., associate professor of biochemistry and biomedical sciences at McMaster University

In the study, researchers introduced a group of proteins known as hemagglutinin into CoPop liposomes. One hemagglutinin in particular, known as trimeric H3 HA, elicited a strong immune response in mice.

“Nanoparticles transport trimeric H3 to the body’s immune cells and cause those immune cells to respond more strongly to the flu,” says lead author Zachary Sia, a Ph.D. candidate for Lovell’s laboratory.

In experiments related to the H3N2 strain of the flu virus, the blood serum of vaccinated mice was injected into unvaccinated mice. The injection provided protection against H3N2. In experiments with ferrets involving a more modern H3N2 strain, the vaccine reduced the amount of virus in the animals ’upper respiratory system.

Even at doses as low as 2 nanograms, the vaccine provided a level of protection similar to that of vaccines with doses normally measured in micrograms, or about 1,000 times more.

“The dose-saving effect is important because it means we could create many more doses with fewer materials,” says senior co-author Bruce Davidson, Ph.D., associate professor of anesthesiology at the School of Medicine and Biomedical Sciences. of Jacobs at the UB. “Simply put, CoPoP is likely to provide greater immune protection with less hemagglutinin than current vaccines.”

He platform is also versatile.

The researchers were able to simultaneously bind 10 recombinant proteins representing different strains of influenza virus to generate a highly multivalent nanoparticle. A 5-nanogram dose in mice offered protection against the strain of H5N1 flu, better known as bird flu, a virus that epidemiologists say can trigger a pandemic.

Researchers find that the intranasal flu vaccine improves the immune response and offers broad protection

More information:
Zachary R. Sia et al., “A hemagglutinin vaccine platform shown with liposomes protects mice and ferrets from the challenge of the heterologous influenza virus.” PNAS (2021).

Citation: Fighting Influenza: Effective Nanoparticle Vaccine in Preclinical Trials (2021, May 24) Retrieved May 24, 2021 at -vaccine-effective.html

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