they can react to their environment. The TruCulture tubes are customized to include, along with the nutrient mixture, any of the immune system irritants or stimulants that interest a researcher. The whole sample-taking procedure can be done by a phlebotomist—the kind of technician who draws your blood in a clinic. Once the tubes have been incubated for about a day, they’re frozen, and shipped to Austin for analysis at Myriad RBM.
“This gives you the option to do this in a very reproducible way,” McDade says.
Scientists at the Institut Pasteur are hoping to establish an easy-to-use, uniform testing platform that could reliably record immune-system responses in many different research studies, and eventually, in the doctor’s office. Highly accurate, consistent test results could help investigators harmonize clinical trial methods and get more out of swapping their data, the researchers say.
Although the Institut Pasteur investigators found individual differences among their first 25 trial participants, they also noted that almost every substance they used to stimulate immune cells produced a characteristic pattern of proteins in a particular ratio to each other.
McDade says these signature patterns could help drug companies discover new uses for drugs that have already been approved for an entirely different disease. Pharmaceutical companies could study the immune system responses raised by their existing drugs—an output of certain proteins by blood cells—and look for clues about other diseases that might be vulnerable to the same combination of proteins.
There’s already an example of this in medical practice, McDade says. For years, doctors would use a tuberculosis vaccine to treat certain patients with bladder cancer. “In 50 percent of patients, the vaccine would cause collateral damage to the tumor cells,” he says.
The 1,000 participants recruited to the Milieu Interieur project between 2012 and 2013 are all of European descent. McDade says the researchers wanted to gauge first how much variation exists in the immune responses of a fairly homogeneous population. As more of the 1,000 participants are tested, the continuing study may reveal how common each of the differences are in the broader trial population.
It may also shed some light on the meaning of the most unusual variation found among the first 25 people tested—the few who never produced the missing protein interleukin one alpha. This might put them at a disadvantage, but it might also turn out the other way.
“Maybe these are people who don’t ever develop cancer, an allergy, or an immune disorder,” McDade says.
