The new double-layered nanoparticles vaccine, developed by researchers from the Center for Inflammation, Immunity & Infection at the Georgia State University Institute for Biomedical Sciences, contains two major influenza proteins — matrix protein 2 ectodomain (M2e) and neuraminidase (NA) — and is effective in providing broad, long-lasting protection against different strains of influenza virus in mice.
TEM image of double-layered M2e-NA nanoparticles. Scale bar – 500 nm. Image credit: Wang et al, doi: 10.1002/adhm.201901176.
The influenza virus protein M2e is found in all influenza virus strains, with each strain having a very similar version, and the protein has mutated very slowly over time.
The protein NA is found on the surface of influenza virus and has also mutated much slower than other influenza proteins.
The new double-layered nanoparticle vaccine uses M2e as its core, and NA is coated on the surface.
“This nanoparticle antigen combination conferred mice with strong cross protection. It can protect mice from different strains of influenza virus,” said Ph.D. student Ye Wang, first author of the study published in the journal Advanced Healthcare Materials.
“Each season, we have different flu strains that affect us. By using this approach, we hope this nanoparticle vaccine can protect humans from different strains of influenza virus.”
In the study, mice were exposed to one of six influenza virus strains after receiving the nanoparticle vaccine by intramuscular injection.
The vaccine proved to have long-lasting immune protection, which was unchanged against viral challenges up to four months after immunizations.
“It’s important to mention that a lot of flu vaccines haven’t focused on NA before,” said Dr. Gilbert Gonzalez, co-author of the study.
“NA is becoming a more important antigen for influenza vaccine research. Previously, it had been ignored or discounted because hemagglutinin (HA) is much more dominant. When you get a flu infection, your body reacts to the HA.”
“However, the HA protein mutates very quickly, which is why seasonal flu vaccines must be changed by scientists every year. Someone could get the flu this year and develop immunity against that particular HA protein, but by next flu season, the HA protein would have rapidly changed and they wouldn’t be protected again.”
“The results demonstrate that double-layered protein nanoparticles containing M2e and NA proteins can be developed into a universal influenza vaccine or a synergistic component of such vaccines,” the researchers said.
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Ye Wang et al. Double-Layered M2e-NA Protein Nanoparticle Immunization Induces Broad Cross-Protection against Different Influenza Viruses in Mice. Advanced Healthcare Materials, published online December 15, 2019; doi: 10.1002/adhm.201901176
