The Stanford work raises the possibility that humans could make use of this immune response if their immune system compromised.
The evidence shows that a fruit fly’s immune response can adapt to, or retain memory of, an earlier infection. Such memory of a specific pathogen, known as adaptation, is supposed to be a hallmark of the higher-level immune system response of humans and other vertebrates.
Using this adaptation in the immune system might also be beneficial in the body’s defense against AIDS, bioterrorism or disease pandemics, noted the scientists.
In the study, some flies were injected with killed bacteria and others with just saline solution. A week later both groups were reinjected with a dose of live bacteria. Then percentage of how many survived was calculated, compared with the flies that been injected only with saline.
Within two days, the second dose killed almost all of the flies that had initially received just saline solution. Those that had been vaccinated lived just as long as a separate group that had not been infected.
In the study, the researchers conclude that a much-studied receptor called Toll is involved, as are other processes. The researchers said they hope their work encourages the search for a similar adaptive response in the innate immune systems of humans or other vertebrates.