A worm-and-mouse tale: B cells deserve more respect

Feb 26, 2009

By studying how mice fight off infection by intestinal worms - a condition that affects more than 1 billion people worldwide - scientists have discovered that the immune system is more versatile than has long been thought. The work with worms is opening a new avenue of exploration in the search for treatments against autoimmune diseases like diabetes and asthma, where the body mistakenly attacks its own tissues.

The findings, reported by scientists who performed the work at the Trudeau Institute in Saranac Lake, N.Y., and who are now at the University of Rochester Medical Center, appear in the March issue of the journal Immunity. The article was published online Feb. 26.

The research focuses mainly on B cells, one of many types of immune cells that the body maintains to fight off invaders like bacteria, viruses, and parasites. Besides B cells, there are T cells, macrophages, neutrophils, monocytes, mast cells and others, all working in concert to keep an organism healthy. The cells cruise our bodies, looking to eliminate infectious threats before they become a serious risk to our health.

For many years, scientists believed that the major job of B cells was to identify foreign invaders and tag them with antibodies, marking the microbe for destruction by the immune system. But scientists are discovering that B cells do much more, resulting in new information about our immune system that could be useful for developing more effective vaccines and better treatments for many types of disease.

In the past few years, Frances Lund, Ph.D., professor of Medicine in the Division of Allergy/Immunology and Rheumatology at the University of Rochester Medical Center, has found an array of unexpected functions for B cells. In the laboratory, she has found that B cells produce chemical signaling molecules known as cytokines that spur other immune cells in the body to action. Her team has also shown that B cells are crucial for presenting to T cells snippets of proteins from invaders, so that the T cells can recognize the invader, a crucial step that allows T cells to mature into useful cells which can then fight an infection efficiently.

In the new paper, Lund's team tested how the findings actually translate by watching closely as an organism - in this case, a mouse - actually fights off infection by a parasite. They chose to study the intestinal parasite Heligmosomoides polygyrus, a bright red worm about one-third of an inch long that infects mice.

It's a cousin of the scores of worms that infect more than 1 billion people worldwide. Roundworms, hookworms, pinworms, and others - these and other worms cause fatigue, diarrhea, nausea, and death.

"Nematodes - worms - sicken a lot of people, they can cause severe malnutrition, and they play havoc with the immune system, making many people more vulnerable to other threats, such as malaria," said Lund, whose project was funded by the National Institute of Allergy and Infectious Diseases.

The team not only verified the additional actions of B cells that they've discovered in the laboratory, but, importantly, they showed that these functions are crucial for the organism to fight off infection.

Lund's team showed that the chemical messengers produced by B cells, such as interleukin-2 and tumor necrosis factor, are necessary for the immune system to protect mice against Heligmosomoides polygyrus. The team also showed that B cells must be present in order for T cells to mature and operate properly.

"It's long been dogma that B cells need the help of T cells to make antibody. That's in all the textbooks," said Lund. "Now work from our laboratory and others shows that it's a two-way street, that T cells need the help of B cells also."

B cells' effects on T cells may open a new window on such diseases as lupus, asthma, multiple sclerosis, and diabetes, where doctors know that T cells are active. Maybe manipulating B cells offers a new way to affect the activity and survival of the T cells that cause disease.

The work also brings up the possibility of more targeted treatments than current treatments, which generally affect all B cells. Lund has found that different B cells produce different collections of chemical signaling molecules. Someday, instead of having a drug that simply targets all B cells, it may be possible to target a specific type of cell, cutting down side effects and making a treatment more effective.

"It may be that only certain B cells play a role in damaging immune responses. If we can narrow down the group of cells at the root of the problem, we may be able to find important new targets for improving treatment," said Lund.

Source: University of Rochester Medical Center

Explore further: US scientists make embryonic stem cells from adult skin

add to favorites email to friend print save as pdf

Related Stories

Research team implants human innate immune cells in mice

Mar 18, 2014

(Phys.org) —Overcoming a major limitation to the study of the origins and progress of human disease, Yale researchers report that they have transplanted human innate immune cells into mouse models, which ...

Two new weapons in the battle against bacteria

Feb 13, 2014

Proteases are vital proteins that serve for order within cells. They break apart other proteins, ensuring that these are properly synthesized and decomposed. Proteases are also responsible for the pathogenic ...

Recommended for you

Leeches help save woman's ear after pit bull mauling

Apr 18, 2014

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...

New pain relief targets discovered

Apr 17, 2014

Scientists have identified new pain relief targets that could be used to provide relief from chemotherapy-induced pain. BBSRC-funded researchers at King's College London made the discovery when researching ...

User comments : 0

More news stories

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Study says we're over the hill at 24

(Medical Xpress)—It's a hard pill to swallow, but if you're over 24 years of age you've already reached your peak in terms of your cognitive motor performance, according to a new Simon Fraser University study.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.