A new bioengineering trick turns immune cells, typically protectors of the body, into disease detectives as well. Sanjiv "Sam" Gambhir, MD, PhD, the researcher behind the engineering feat, is using the technique as a new approach to diagnose cancer, which he's so far demonstrated in mice.
"We said, if nature doesn't give you sufficient signal that cancer is present, can we force the body to make one?" Gambhir said in our news release. "In this case, can we force immune cells to emit detectable markers if cancer exists somewhere in the body?”
Perhaps you're familiar with immunotherapy, the therapeutic tactic that takes an individual's immune cells and reengineers them to deliver a treatment of some kind. Gambhir's approach is kind of like that, only it harnesses immune cells to send an alert instead. These immune cells sniff out other cells that are malfunctioning or damaged, and send out a signal to reveal their presence. It's known as "immunodiagnostics" and according to Gambhir, it's the first time that the method has been demonstrated in an animal.
From our release:
Currently, the technique can detect tumors as small as 4 millimeters in diameter — about the size of a pencil top eraser — which outperforms some of the most advanced early tumor detection methods out there, Gambhir said.
He said the immune cell signals are flagging a specific class of malfunctioning cells, which includes tumor cells, but is not limited to them. The technique also could be tailored to detect more than just cancer, and could potentially flag other disorders, such as multiple sclerosis or chronic inflammation, he said.
These immune cells, called macrophages, naturally scout the body for any suspicious-looking cells, such as those found in tumors. And when they detect them, they transform into in active state of sorts, where they can then gobble up the faulty cells.
Gambhir's method uses that process to its advantage. The scientists artificially attach a biomarker to macrophages, and when the cell comes into contact with a tumor environment, the biomarkers are released into the bloodstream, sending out an alert that something's up.
From there, picking up on the biomarker is as simple as taking a blood or urine sample. Collected in a vial, a special chemical added to the sample will cause the fluid to glow if the marker is present. From the release:
In the immediate future, Gambhir said that he plans to continue to test the detection method in other types of cancers and animal models, likewise refining the method to home in on tumor cells only, rather than cells with other types of damage.
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