Alligator blood may provide basis of wartime anti-infectives

The Defense Threat Reduction Agency has funded a study into "sophisticated germ fighters" that may protect soldiers in the field from infection. However, these germ busters do not originate from a petri dish or test tube, but somewhere altogether more dangerous. The source? Alligator blood.

George Mason University professor Barney Bishop poses with "Fluffy," an American alligator.
Image credit: St. Augustine Alligator Farm Zoological Park

The Agency's project is in its fourth year and, if fully funded over 5 years, will be worth $7.57 million. 

A 17-member multidisciplinary research team at George Mason University in Fairfax, VA, is conducting the research, the latest results of which are published in the journal PLOS ONE.

Although the team is looking at ways to protect wounded soldiers on the battlefield from infections or biological weapons, the researchers believe their work will also benefit civilians.

The researchers at the School of Systems Biology and the National Center for Biodefense and Infectious Diseases at Mason, say: "We hope that these could be the basis to develop new treatments."

The Mason team turned their attention to alligators from the observation that, despite living in bacteria-laden environments and feasting on carrion, these creatures rarely fall ill. The researchers suspected that antimicrobial peptides - small proteins that are part of the innate immunity of all higher organisms - may be behind alligators' enhanced immunity.

Unlike antibodies, which are produced to fight specific bacteria or viruses, peptides offer more general protection.

Innate immunity may work less well than antibodies, but it works well enough. The reason why we're so interested in them: they are part of nature's way of dealing with the onslaught of bacteria and viruses that we face every day. Every breath that you take, every thing that you eat, you're constantly exposed to bacteria and your body needs to fend them off in some way.

Researchers surprised to find alligator peptides are fragments of larger proteins

The Mason team analyzed blood samples provided by another team from the University of Florida and the St. Augustine Alligator Farm Zoological Park in St. Augustine, FL. They were surprised by the "sophistication and diversity" of the peptides in the alligator blood.

Fast facts about alligators

• The American alligator can grow up to 11.2 ft long and weighs nearly half a ton
• Alligators have been known to use tools to snare prey, including using small sticks to attract nesting birds. They also eat fruit in addition to prey and carrion
• One of the earliest relatives of the alligator was the 40 ft Deinosuchus, which stalked North America 70 million years ago.


Alligators are one of the most ancient animals on Earth. Over the course of 37 million years, these reptiles have evolved what the Mason team describes as a "formidable defense against bacterial infections."

Using custom-made nanoparticles, the Mason researchers were able to capture peptides from the complex soup of proteins and peptides in alligator plasma.

However, the team was surprised to discover that these unusually potent peptides were fragments of larger "parent" proteins.

Next, the team will compare their findings on the alligator peptides with samples taken from Siamese crocodiles, Nile crocodiles and gharials - the crocodiles native to the Indian Subcontinent.

References:

1.       Bioprospecting the American alligator (Alligator mississippiensis) host defense peptidome, Monique L. van Hoek, et al., PLOS ONE, doi: 10.1371/journal.pone.0117394, published online 11 February 2015.

2.       George Mason University news release, accessed 12 February 2015 via EurekAlert.
Additional source: Metal Floss, 11 terrifying and amazing facts about alligators, accessed 12 February 2015.

3.       Additional source: LiveScience, Facts about alligators, accessed 12 February 2015.