News Release 06-141
"Killer" B Cells Provide New Link in the Evolution of Immunity
Immune cells play different roles in fish and mammals
October 3, 2006
This material is available primarily for archival purposes. Telephone numbers or other contact information may be out of date; please see current contact information at media contacts.
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.
Funding for this research was provided by the National Science Foundation and United States Department of Agriculture.
The full University of Pennsylvania news release is posted at http://www.upenn.edu/pennnews/article.php?id=1009.
The U.S. National Science Foundation propels the nation forward by advancing fundamental research in all fields of science and engineering. NSF supports research and people by providing facilities, instruments and funding to support their ingenuity and sustain the U.S. as a global leader in research and innovation. With a fiscal year 2021 budget of $8.5 billion, NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and institutions. Each year, NSF receives more than 40,000 competitive proposals and makes about 11,000 new awards. Those awards include support for cooperative research with industry, Arctic and Antarctic research and operations, and U.S. participation in international scientific efforts.