According to the Spanish national newspaper website November 1st, influenza virus is one of the most elusive viruses. In addition to hundreds of known types, subtypes and strains, the mutation rate of influenza viruses, which avoid the identification of epidemic systems by mutation, is also very high. Influenza viruses can escape the pursuit of the epidemic system mainly because of the hemagglutinin on their surface. This trimer protein has two meanings: it can make the virus adhere to infected cells, but it is also the most exposed part, and the defense system will react to it first.
Reported that, therefore, most of the current vaccines against hemagglutinin attack, especially the top of the trimer structure. But this part is also the most prone to mutation. In 1968, the first outbreak of influenza from Hong Kong became the third pandemic in the 20th century, with nearly a million deaths in less than a year. The main reason why the Hong Kong flu was so destructive was that the human defense system had not been trained at that time. The H3N2 virus, the pathogen of influenza in Hong Kong, is due to its variability on the top of the trimer, leading to delays in the detection of antibodies against the virus.
So researchers developed a complex and very different strategy: Since the top of haemagglutinin is highly variable, why not attack the stem that connects the top to the rest of the virus? Researchers conducted preliminary experiments on mice, which showed that almost all mice survived at lethal doses of influenza for several months.
It is reported that the American Journal of science has released an inspiring experiment. Unlike the top, hemagglutinins stem hardly changes over time. In addition, the stems of different viruses are very similar. The theory is flawless: if people find an antibody that can attach to the stem of the virus hemagglutinin, they can prevent the virus from adsorbing to the cell using the top of the hemagglutinin. But most antibodies do not respond to this part of the virus, and even if they do, they cannot dock. The key to open the lock is hidden on the camel and alpaca.
According to the report, Yoster Kolkman, a researcher in the infectious diseases and vaccines Department of the Dutch company Jansen, and 30 other scientists selected four different antibodies from a group of alpacas that were immunized by injecting different influenza virus vaccines or by immunizing against influenza virus hemagglutinin. Researchers found that these antibodies can detect and react to haemagglutinin in the culture process, and three of them can act on the stem of haemagglutinin. But each antibody can only respond to a specific virus. In addition, these antibodies are univalent, in other words, they can only attach to one connection point. Therefore, the researchers decided to combine multiple antibodies and develop a super antibody. These antibodies can easily connect to each other to form multi-specific antibodies that can attach to different sites of the virus or to different viruses, Colkman said. This multi specificity is the key to achieving a wide spread coverage of influenza viruses and other highly susceptible pathogens. (compile / Liao Siwei) this article source: Reference News Net editor: Zhang Zutao _NT5054