Many people still choose not to vaccinate their children, but it seems that bees don’t have a choice. Every bee that hatches is already primed with the immunity to fight the bacteria that it will likely encounter when it eventually leaves the hive to forage for nectar and pollen. Researchers looking into how the insects manage this have finally worked it out.
“I have been working on bee immune priming since the start of my doctoral studies,” said Dalial Freitak, who co-authored the paper published in PLOS Pathogens. “Now almost 10 years later, I feel like I've solved an important part of the puzzle. It's a wonderful and very rewarding feeling!”
It turns out that it all comes down to a particular protein called vitellogenin. When worker bees are out buzzing from flower to flower, they encounter and pick up various bacteria and pathogens, and inadvertently bring them back into the hive. These bees then turn the collected pollen into food in the form of “royal jelly,” which is inevitably infected with the bacteria from the outside.
The royal jelly is then fed to the queen, who subsequently breaks down the bacteria contained within and transfers the products to what’s called the queen’s “fat body,” an organ similar to the liver. It is here where the vitellogenin comes in. The fragments of bacteria are bound to the protein, which then enters back into the queen’s blood, ultimately ending up in the developing eggs she’s making. This means that when the new bees finally emerge, they’re already “vaccinated,” with their immune systems primed to the bacteria in their environment. This could be likened to how human mothers offer some protection against pathogens to their babies by transferring antibodies across the placenta.
“The process by which bees transfer immunity to their babies was a big mystery until now. What we found is that it's as simple as eating,” explained Gro Amdam, another of the co-authors, from Arizona State University. “Our amazing discovery was made possible because of 15 years of basic research on vitellogenin.”
The researchers hope that they can use this knowledge to produce an edible bee vaccine that could be fed to the insects to help protect them against other, more deadly diseases that they cannot naturally protect themselves against. One example of a disease they suggest could be tackled with a synthetic bee vaccine is American foulbrood, a deadly disease caused by the bacterium Paenibacillus larvae, the spores of which feed off and kill bee larvae. This would be the first ever insect vaccine.
As vitellogenin is found not just in bees, but in all other egg-laying animals, from butterflies to turtles, this new understanding of how it works could even have applications in the field of conservation, helping to protect endangered species, or in farming with the vaccination of poultry.