Research performed at the National Institutes of Health (NIH) has identified antibodies that target a region of the influenza virus nicknamed the “dark side” of the neuraminidase (NA) protein head, suggesting a new target for countermeasures preventing against the virus.
The underside of the NA surface protein on the influenza virus is a so-called “conserved” region on the virus, which means that it “tends to be relatively unchanged between different strains of the virus.” Termed the “dark side” due to its “partially hidden location and relatively unexplored characteristics,” the conserved region on the NA surface protein contains “targets for antibodies—known as epitopes—that make it vulnerable to antibody binding and inhibition of the virus, as well as not being impacted by mutations common in drug-resistant strains.”
The researchers “isolated human antibodies that target the NA dark side from the blood of two people who had recovered from influenza type A subtype H3N2, a major subtype of seasonal flu viruses. In lab tests, the antibodies inhibited propagation of viruses from subtype H2N2, the subtype that caused pandemic influenza in 1957-58, and H3N2 viruses from humans, swine, and birds.” In addition, the scientists discovered that two of the antibodies each targeted “different, nonoverlapping regions of the dark side, demonstrating that this region has multiple areas that may be useful to explore for countermeasure development.”
The findings demonstrate that “the NA dark side has unique, previously untapped epitopes that could be applied to the development of new vaccine and therapeutic strategies.” This research points a hopeful way forward, as it suggests that these antibodies could be used alongside antivirals or other types of antibodies for “interventions against influenza.” The researchers are optimistic that “NA dark side targets could be included in the next generation of broadly protective vaccines against influenza.”
Influenza, or flu, is such that “updated vaccines are needed each season to provide protection against the many strains and subtypes of the rapidly evolving virus.” Since these antibodies targeting the NA dark side seem to work against multiple subtypes of the influenza virus, they could eventually aid in preventing “outbreaks of new and reemerging flu viruses without the need for yearly vaccine without the need for yearly vaccine reformulation or vaccinations,” an enduring goal.
NIH’s website has the news release.
