New Antibody May Be Able to Neutralize a Number of Influenza Strains

A new, adaptable antibody, discovered by researchers at the Dana-Farber Cancer Institute, can mutate to neutralize a number of influenza strains. Created by “memory” B cells within the immune system, researchers hope that this antibody can potentially be used in the development of “universal” influenza vaccines, according to the institute’s official press release.

The study, published in the journal Nature Communications, was led by Wayne A. Marasco, MD, PhD, a cancer immunologist and virologist at Dana-Farber Institute. Back in 2009, Dr. Marasco discovered “broadly neutralizing antibodies.” With the assistance of a team of researchers, Dr. Marasco discovered 3I14 mAb, a “broadly neutralizing antibody,” that is able to target and neutralize not just one, but 18 global strains of influenza, according to the press release. Researchers found that this particular antibody, 3I14 mAb, had the potential to neutralize group 1 and 2 of the influenza A virus. In addition, researchers found that despite administering a deadly dose of influenza to mice, this antibody was able to offer sufficient protection to the animals.

This new antibody is composed of white blood cells that live within the body’s bone marrow and spleen, but travel throughout the blood stream, otherwise referred to as the immune system’s “memory” B cells, according to the press release. The “memory” B cells are able to recognize and remember exposure to different strains or types of harmful pathogens as well as vaccines that contained said pathogens. With this ability, these “memory” B cells “constitute a reserve defensive force that can quickly recognize and attack the microbe or virus should it enter the body again,” according to the press release.

Influenza is a respiratory infection that is caused by influenza viruses that target the throat, nose, and lungs, and is incredibly contagious due to the fact that it can easily be transmitted through stray droplets produced and spread through coughing, sneezing, or talking, according to the Centers for Disease Control and Prevention. The best prevention strategy to avoid infection is vaccination. However, the influenza virus is known to undergo constant changes each season. Sometimes, it can combine with other strains of flu found in different animals, such as birds. This combination can cause pandemics, such as the 2009 H1N1 Pandemic.

Dr. Marasco and his team used various strains of influenza to “challenge” the “memory” B cells in blood samples that had been taken from seven different donors who had “broadly neutralizing antibodies” within their blood.

When speaking of the study’s results, Dr. Marasco said that there was one reservoir of “memory” B cells “that recognized all the strains we screened against it,” according to the press release. The team took a closer look at this population and found a gene that was responsible for telling the 3I14 antibody what to do. This antibody was able to bind to the virus, but at the same time, was still able to undergo the proper mutations that would allow it to neutralize the flu strains.

In the next step of their study, the researchers aimed to find out if this antibody could also neutralize strains that it had not been exposed to in the past. They introduced an H5 type bird flu virus and initially found that the antibody failed to bind itself to the virus strongly enough to carry out its instructions. The researchers then mutated “one letter of the genetic code,” and as a result, the antibody was able to efficiently neutralize the H5 type bird flu virus.

The results of the study suggest that these immune system “memory” B cells can be used to not only neutralize pathogens that they had been exposed to in the past, but also neutralize pathogens that they have yet to come into contact with. The use of broadly neutralizing antibodies could potentially recognize, target, and neutralize all influenza strains in the future.

Dr. Marasco feels that these findings can inform the development of future vaccines that work to increase reservoirs of “memory” B cells that “aren’t committed to making a single antibody type,” according to the press release.