Tooth, Claw, and Antibodies

What can we learn from crocodiles and their immune system?

There was once a time in our world, millions of years ago, where trees, plants, insects, and animals grew in much larger proportions. Three-foot-long dragonflies were common; some mammals such as the Columbian mammoth stood 17 to 20 feet tall, and even the small sloth we know today had a relative that stood taller than many modern humans! Gargantuan dinosaurs roamed the land and colossal terrors ruled the waters. Fortunately for us relatively small and frail human beings, many of these prehistoric titans no longer live and breathe, though their descendants live among us. Birds are close relatives to ancient dinosaurs, and the mammals we all know and love are descendants of those that survived the mass extinctions.

However, there are those that have survived the ravages of time. Through meteor impacts, volcanic eruptions, and ice ages they have fought tooth and claw for survival. Among those few there is one creature that has evolved adaptations that make it a fiercely efficient and capable predator: the crocodile.

The crocodile species, it is believed, has survived nearly 200 million years with little change to its biological design. In the modern world, as I’m sure it was those millions of years ago, the crocodile is considered to be an apex predator. Everything in its physiology is built to make it a perfect survivor. As humble humans with only several thousand years of history under our species’ belt, we can ask, “What can we learn from the crocodile?”

The answer lies in the crocodile’s amazing immune system!

Scientists from tropical northern Australia have discovered that, despite gaping wounds and missing limbs due to disputes over territory and food, crocodiles are able to resist dangerous infections while living in aquatic environments filled with microbes. Needless to say, in comparison to our own, a crocodile’s immune system is incredibly powerful. As soon as an infectious intruder enters the bloodstream, the crocodile’s immune system attacks it directly. In the case of bacteria, the antibodies tear it apart lipid by lipid (or capsomere by capsomere in the case of viruses!) These crocodile antibodies have destroyed penicillin-resistant bacteria such as Staphylococcus aureus (gold staph) and are even more effective in killing HIV than the human immune system.

The hope is to create a human-friendly version of these powerful antibodies that we may someday take in the form of pills or topical salve. With thousands of people dying from flu- related complications, millions now living with HIV (of which half die after developing AIDS) biomimetic research in the field of medicine offers us a ray of hope. We are always working toward a better, brighter, and cleaner future. Looking to nature’s wonders can help us get there!

Javier Banuelos is a volunteer with the San Diego Zoo’s biomimicry programs. Read his previous post, A Breath of Fresh Air. Learn more about the field of biomimicry.

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