Evolution in action: Our antibodies take 'evolutionary leaps' to fight microbes

Jan 05, 2009

With cold and flu season in full swing, the fact that viruses and bacteria rapidly evolve is apparent with every sneeze, sniffle, and cough. A new report in the January 2009 issue of The FASEB Journal, explains for the first time how humans keep up with microbes by rearranging the genes that make antibodies to foreign invaders. This research fills a significant gap in our understanding of how the immune system helps us survive.

"We've known for a long time that our antibody-forming system adapts itself to every microbe we encounter," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, "but what we didn't understand fully is exactly how this happens. Now that we know, we can begin to find ways to manipulate this process so illnesses can be prevented or made significantly less dangerous."

When the body encounters a foreign invader, like a virus or bacterium, it immediately begins to find a way to neutralize it by means of cellular or antibody-mediated defenses. Part of the process involves tailoring the genes that code for antibodies to specific viruses or bacteria. Researchers have known that this involves two types of genetic manipulation. One type changes a single gene at a time, and the other type changes multiple genes at the same time. In the report, scientists from Wayne State University in Detroit describe how multiple genes can be modified simultaneously to make the "evolutionary leap" necessary to stave off infection.

The basic setup of the experiment treated DNA responsible for making antibody molecules with an enzyme, called activation-induced deaminase, while the DNA was being copied by RNA polymerase. Like a scanner, RNA polymerase moves across the DNA to copy it. When this scanning process moved smoothly, there were either single mutations or no mutations. When the researchers made the RNA polymerase stall along the DNA (under certain conditions), it caused several mutations at once (cluster mutations) in the DNA, adapting our antibodies for a rapid and effective response to a new microbial invader.

"As the planet warms, infectious diseases may be one the biggest threats to human survival," Weissmann added. "Nowadays, mosquitoes, parasites and viruses cause diseases in the United States that were once isolated to warmer parts of the world. They evolve, and - a la Darwin - so does our immune system each time we meet a new microbial invader."

Article details: Chandrika Canugovi, Mala Samaranayake, and Ashok S. Bhagwat. Transcriptional pausing and stalling causes multiple clustered mutations by human activation-induced deaminase. FASEB J. 2009 23: 34-44. www.fasebj.org/cgi/content/abstract/23/1/34

Source: Federation of American Societies for Experimental Biology

Explore further: Into the dark: Two new encrusting anemones found in coral reef caves

add to favorites email to friend print save as pdf

Related Stories

Mutating virus suppresses cow's immune response

Sep 04, 2014

Bovine viral diarrhea virus infections result in one of the most costly diseases among cattle with losses in U.S. herds estimated at $2 billion per year, according to professor Christopher Chase of the South ...

New tool identifies therapeutic proteins in a 'snap'

Aug 21, 2014

(Phys.org) —In human and bacterial cells, glycosylation – the chemical process of attaching complex sugar molecules to proteins – is as fundamental as it gets, affecting every biological mechanism from cell signaling ...

Antibodies from the desert as guides to diseased cells

Jun 12, 2014

Nanoparticles are considered a promising approach in detecting and fighting tumour cells. The method has, however, often failed because the human immune system recognizes and rejects them before they can ...

Recommended for you

Blind beetles show extraordinary signs of sight

11 minutes ago

University of Adelaide researchers have made a surprising discovery in the aquifers beneath the Western Australian desert, which challenges the traditional Darwinian view of evolution.

Every time a fig is born there is a wasp massacre

17 minutes ago

"Don't put all your eggs in one basket" is a common refrain. But usually it is not followed by the words "because your neighbours may kill you". However, this is precisely the scenario faced by some female ...

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.