Biting Edge Research
Project is first study ever of the alligator immune system
Dr. Gomez and a research subject.
HOUSTON—(Oct. 19 2000)—The teeth that flash, the claws that slash have served the alligator well for nearly 250 million years. Crocodilians - the large reptiles that include alligators - have remained virtually unchanged since the time of the dinosaurs. When an alligator is injured, it is not teeth or claws but quite possibly a remarkable immune system that protects the animal from pathogens commonly present in the murky water and muddy shore. A quest for a better understanding of how these animals protect themselves against overwhelming infection in such naturally contaminated environments (the role of their immune system) has broadened the research of Henry F. Gomez, M.D., from children to alligators.
An assistant professor of pediatrics-infectious diseases at the University of Texas-Houston Health Science Center Medical School, Gomez is conducting the first and only project in the world studying the alligator immune system, with the expectation that the knowledge can be applied to humans. "On-site observations of these creatures seem to defy the laws of logic when it comes to infections," Gomez said. "Traumatic injuries will heal extremely rapidly, with a very low chance of becoming infected. It is not unusual to see a spectrum that ranges from small cuts to horrific injuries (tails eaten, legs bitten off, jaws ripped apart) heal within a matter of days to weeks with virtually no sign of infection, save for some external scar tissue even in highly naturally septic environments."
First-hand observation of the rapid healing of an injured alligator at Brazos Bend State Park in March 1999 intrigued Gomez. After viewing a program on the Discovery Channel, "Crocodilians: The Ultimate Guide," he e-mailed the program's scientific advisor, Adam Britton, Ph.D., research officer for Wildlife Management International, currently in Darwin, Australia, to ask if Britton could explain the amazing healing power of the alligators. The answer: "I don't know and I don't think anybody knows. The world of immunology is an untapped one with crocodilians, and I really think this area would yield some fascinating information."
After a literature search and consultation with experts around the world indicated that crocodilian immunology has been neglected, Gomez developed a protocol for establishing a baseline databank on the components of the immune response in the healthy American alligator. The databank will include functional studies of different types of blood cells and their components, basic markers of humoral immunity, and DNA.
Henry F. Gomez, M.D., draws blood from a 12-foot-long alligator as part of an immunological study. Although the alligator is temporarily immobilized, neither the animal nor the human researchers have been injured.
Obtaining blood samples of 6- to 12-foot-long alligators is a challenge. Gomez has been helped by the animals' natural curiosity, Britton's personal instruction on bleeding techniques, and assistance from park rangers at Brazos Bend State Park and an alligator farm in St. Augustine, Fla. Empty soft drink cans are used as bait to lure a curious alligator looking for food. Once the alligator is captured, the first priority is to secure the snout by tying it shut. A blindfold further soothes the animal, and finally the alligator's legs are restrained. Obtaining the blood sample takes only a few minutes, and the animal's tail is tagged so that the research team doesn't mistakenly sample the same animal again. The alligators are turned to face the water before they are released. They generally head straight for the water while the people scurry in the opposite direction, Gomez said. From the moment of capture to the release, the whole process takes only 15 minutes. So far, samples have been taken from 65 alligators, and neither humans nor alligators have been injured in the process. The goal is to obtain 100 samples. "Alligators are comparable to sharks in that both are top predators and have managed to stay on top of the evolutionary ladder for millions of years," Gomez said. "When alligators reach maturity (about six feet long), they do not have natural enemies, except bigger 'gators and man. "Alligators have been interacting with all kinds of pathogens (bacterial, viral, parasites) for millions of years, thus it's extremely logical to think that they have learned to deal with and protect themselves against these organisms," he said. "The primary system in charge of dealing with these organisms, by definition, is the immune system. I am very confident that when these studies are completed, we will be able to understand how they protect themselves against infection and how is it that they heal so quickly and so well. Once we have understood how, then the application into humans is not so far away, considering the current technologic advancements."
— By Ina Fried, Institutional Advancement