Here’s What Happens When You Put A Human Immune System In A Cow

To help doctors testing treatments for cancer and other diseases, these farm animals can now respond to drugs just like a person would.

Here’s What Happens When You Put A Human Immune System In A Cow
[Image: Flickr user Kevin Walsh]

Sioux Falls is the biggest city in South Dakota, but with a population of 153,888, that’s not saying much. And yet, it has some serious big city research going on at Sanford Health, where researchers are working on ambitious projects like creating a patient registry for every rare disease in existence and replacing bovine immune systems with human ones.


The latter project, which is being conducted under the Sanford Applied Biosciences program, takes a novel approach to developing new disease treatments. “We have cows that produce human antibodies–they’re human beings with respect to their immune system,” explains Dr. David Pearce, the COO and VP of Sanford Research.

Today, a number of disease therapies–including many cancer treatments–use human antibodies. These antibodies bind to targeted cells in the body, triggering the immune system to attack and rid itself of whatever disease process is happening. But while humans produce the antibodies necessary for research, they generally don’t like being poked and prodded (maybe neither do cows, but that’s a different discussion). “The beauty of this is that you don’t have to take blood and harvest things from humans. You can make antibodies from the cows,” explains Pearce.

In order to create a cow with a human immune system, you have to remove its immune regulatory genes and then paste in analogous human immune regulatory genes (removed from a human cell)–kind of like cutting and pasting a word into a document. This is all done with basic stem cells. These stem cells produce embryos that can then be fertilized and turned into full-fledged cows.

Sanford keeps its cows at a facility in Iowa. These cows lead a sheltered life–though it’s probably much more palatable than what they would experience on a factory farm. “They have to be kept in specific conditions. They have a human immune system, not a cow immune system, so they may be somewhat susceptible to bovine afflictions,” says Pearce. “We have a lot of regulations in terms of upkeep.”

So far, Sanford–which is possibly the only organization doing this kind of bovine research–has made antibodies that target a number of viruses and pathogens. In the next 12 to 24 months, Pearce expects that his team will be ready to go to the FDA for further testing (probably for a pathogen treatment).

In spite of all his research, however, Pearce says he has never met the cows in person.

About the author

Ariel Schwartz is a Senior Editor at Co.Exist. She has contributed to SF Weekly, Popular Science, Inhabitat, Greenbiz, NBC Bay Area, GOOD Magazine and more.