'Killer' B cells provide new link in the evolution of immunity

Oct 03, 2006
'Killer' B cells provide new link in the evolution of immunity
In the adaptive immune system in mammals, B cells produce antibodies to fight infection. In the more-primitive innate immunity in fish, scientists found that B cells take part in a process known as phagocytosis, by which immune system cells ingest foreign particles and microbes. The round cell in the lower left is B-cell ike from a trout. It is in the process of engulfing three latex beads, each (arrow) about 1 micron in diameter. Credit: J. Oriol Sunyer, School of Veterinary Medicine, University of Pennsylvania; image taken with the assistance of R. Meade, Biomedical Imaging Core Laboratory of the School of Medicine, University of Pennsylvania.

Researchers from the University of Pennsylvania School of Veterinary Medicine have discovered a unique evolutionary link between the most primitive innate form of immune defense, which has survived in fish, to the more advanced, adaptive immune response present in humans and other mammals.

The finding, which appears in the online version of the October issue of Nature Immunology, represents an evolutionary step for the mammalian immune system and offers a potential new strategy for developing much-needed fish vaccines.

In the adaptive immune system in mammals, B cells produce antibodies to fight infection. In the more-primitive innate immunity in fish, the scientists found that B cells take part in a process known as phagocytosis, by which immune system cells ingest foreign particles and microbes.

In modern mammals, the B cell is a highly adapted part of the immune system chiefly responsible for, among other things, the creation of antibodies that tag foreign particles and microbes for destruction.

"When examining fish B cells we see them actively attacking and eating foreign bodies, which is a behavior that, according to the current dogma, just shouldn't happen in B cells," said J. Oriol Sunyer, a professor in Penn Vet's Department of Pathobiology and leader of the research team.

The researchers determined that these attack B cells account for more than 30-40 percent of all immune cells in fish, whereas phagocytic cells make up only a small portion of the total number of immune cells in mammals.

According to Sunyer, the findings are important for not only understanding the evolution and function of immune cells in fish but also may point to novel roles of B cells in mammals. Their findings also have an agricultural implication. Vaccines currently given to farmed salmon, for example, appeal to the fish's adaptive immune response, which this research now shows to be a small part of the overall fish immune system.

Source: National Science Foundation

Explore further: Study of gene mutations in aplastic anemia may help optimize treament

Related Stories

The nutrition behind good sperm

Jun 25, 2015

Males with low sperm quality probably won't get much help from dining down on fish oil supplements and a bag of carrots, recent aquatic-based research suggests.

Highly efficient CRISPR knock-in in mouse

May 01, 2015

Genome editing using CRISPR/Cas system has enabled direct modification of the mouse genome in fertilized mouse eggs, leading to rapid, convenient, and efficient one-step production of knockout mice without ...

A single-cell breakthrough

Mar 18, 2015

The human gut is a remarkable thing. Every week the intestines regenerate a new lining, sloughing off the equivalent surface area of a studio apartment and refurbishing it with new cells. For decades, researchers ...

Recommended for you

A high-fat diet may alleviate mitochondrial disease

Jun 30, 2015

Mice that have a genetic version of mitochondrial disease can easily be mistaken for much older animals by the time they are nine months old: they have thinning grey hair, osteoporosis, poor hearing, infertility, ...

Cheek muscles hold up better than leg muscles in space

Jun 30, 2015

It is well known that muscles need resistance (gravity) to maintain optimal health, and when they do not have this resistance, they deteriorate. A new report published in the July 2015 issue of The FASEB Journal, however, sugges ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.