Scientists discover how bees naturally immunize their offspring

3 Aug

Even in the larval stage, honey bees already have a natural immunity

against specific diseases in their environment. Now, for the first time, scientists have

discovered how they acquire this immunity.

egg-laying species and vitellogenin
The blood protein through which the queen honey bee passes immunity to her eggs is also present in other egg-laying species.
Image credit: Sabine Deviche/ASU

In the journal PLOS Pathogens, the international team explains that the queen

honey bee passes a blood protein to her eggs.

The protein – called vitellogenin – plays a critical, but previously unknown, role in

protecting bees against disease.

Co-author Gro Amdam, a Norwegian biologist and life sciences professor at Arizona

State University in Tempe, is internationally known for her research on honey bees. She


“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.”

Prof. Amdam and her colleagues, from the University of Helsinki and the University of

Jyväskylä – both in Finland – have been working in this area for more than 10 years.

They say their discovery opens the door to new ways to protect bee colonies against

devastating pathogens from which they have no natural immunity.

How do bees acquire immunity?

In a honey bee colony, the queen bee relies on worker bees to bring her food, as she

rarely leaves the nest. As the worker bees gather pollen and nectar in the environment,

they naturally pick up pathogens.

When they arrive back at the nest, the worker bees use the pollen to make “royal

jelly,” which is fed to the queen. In doing so, they transfer some of the bacteria they

have picked up while foraging.

When the queen eats the royal jelly, she digests the bacteria along with the other

ingredients and passes it to her body cavity. Pieces of digested bacteria eventually end

up in her “fat body” – the bee equivalent of the liver.

In the queen’s fat body, pieces of bacteria become attached to the blood protein vitellogenin,

which is carried through her blood to the developing eggs. The larvae that then

hatch from her eggs have immune systems that are “vaccinated” against some of the

pathogens in their environment and the diseases they cause.

Much of this story was already known; what the new study brings is the discovery that

it is vitellogenin that carries the immune-priming signals.

The team explains that this natural vaccination method only immunizes bees against

some – but not all – deadly pathogens. But, now we know how this happens, perhaps we can

use it to create edible vaccines for insects, they note.

Co-author Dr. Dalial Freitak, a researcher at the University of Helsinki, adds:

“We are patenting a way to produce a harmless vaccine, as well as how to cultivate the

vaccines and introduce them to bee hives through a cocktail the bees would eat. They

would then be able to stave off disease.”

One deadly disease the researchers have in mind is American Foul Brood, which spreads

quickly and destroys honey bee hives.

Bee larvae catch the disease as they ingest food contaminated with spores from the

American Foul Brood bacteria. The bacteria feed on the larvae and kill them.

Bees are important for our food supply

Why should the average person care about bee diseases? Because without bees, we would have a huge gap in our food supply.

Bees and other pollinators are vital for a healthy economy and critical to food security. They are important for the production of fruits, nuts and vegetables.

Estimates suggest honey bees alone support the cultivation of 90-130 crops, which

directly or indirectly account for up to a third of the US diet.

Yet many pollinators – honey bees included – are in serious decline
in the US and worldwide. Over the last 60 years, managed bee colonies in the

US have fallen from 6 million to 2.5 million.

As well as disease, something called colony collapse disorder is responsible for this

staggering loss of important pollinators. Scientists are not sure exactly what causes it, but many believe

pesticides, pathogens and nutrition problems are behind it.

The researchers suggest the new findings could also help in the search for a way to

combat colony collapse disorder.

They also suggest the findings have wider implications for all species that lay eggs – including fish, poultry, amphibians and insects – because they also have vitellogenin in their bodies. One possibility is the production of natural, inexpensive vaccines that the food industry can use. Prof. Amdam concludes:

“Because this vaccination process is naturally occurring, this process would be cheap and

ultimately simple to implement. It has the potential to both improve and secure food

production for humans.”

The Academy of Finland and the Norwegian Research Council contributed funds to the study.

In September 2014, Medical News Today learned how scientists are discovering

that bacteria from bees may offer an alternative to


After running lab tests, researchers in Sweden found that lactic acid bacteria from

fresh honey extracted from bees’ stomachs counteracted many of the strains that cause

severe wounds in humans, including drug-resistant ones such as MRSA, VRE and

Pseudomonas aeruginosa.

Written by Catharine Paddock PhD

Copyright: Medical News Today

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