Report reveals means of H1N1's cellular attack

The H1N1 influenza virus uses a unique and never before seen means of hijacking host cells and amplifying its infection in humans, a new study reports.

H1N1 is a combination of four different avian and swine flu viruses, reports. Generally, two amino acids are needed in particular places on an avian virus protein in order for the virus to make the transition from infecting an animal host to infecting a human host. H1N1 lacks both of these amino acids.

The study, conducted by an international team of scientists and published in the journal PLoS Pathogens, demonstrated that one of these amino acids, lysine, is in an entirely different place on the protein. It is this difference that enables H1N1 to take over human cells. It also makes the virus markedly more lethal.

"This pandemic H1N1 has this mutation and is why it can replicate so well in humans," co-author Yoshihiro Kawaoka told "This gives us another marker to help predict the possibility of future flu pandemics."

In addition, the study revealed data on the three-dimensional structure of the H1N1 protein, known as PB2. According to Kawaoka, this information is critical in understanding how the virus interacts with its host cell. It could help form a basis for antivirals to be used against future viruses that use the same method to infect humans, he told

H1N1 caused a major global epidemic in 2009 and 2010. It infected approximately 34 million people and was responsible for 6,000 deaths in the United States.