Even though it is relatively easy to collect billions of T cells
directly from patient blood, it has historically proved difficult or
impossible to unleash those T cells' natural ability to recognize and
target cancer cells.
Mayo Clinic and University of Washington researchers have discovered a
new culture method that unlocks the natural fighter function of immune T
cells when they are passing through the bloodstream. This allows T cell
armies to be raised directly from blood that naturally recognize and
target proteins that are present on most human cancers. The results are
published in the Oncotarget
‘A new culture method that unlocks the natural fighter function of immune T cells when they are passing through the bloodstream has been discovered by researchers.’
Peter Cohen, a Mayo Clinic
immunotherapist who co-led the study with Mayo Clinic immunologist
Sandra Gendler and University of Washington immunotherapist Nora
Disis, said, "Our method strictly employs natural signals to activate the immune
blood cells outside the body. This gives rise to
expanded armies of T cells, which specifically recognize proteins that
are present on cancer cells and which can be reinfused into patients for
therapeutic evaluations in future clinical trials."
The research team tested the method's ability to stimulate T cell
responses against MUC1, a protein expressed by a large majority of
patients' cancers, including breast, pancreatic, lung, colorectal,
ovarian, kidney, bladder, and multiple myeloma. Also tested were
HER2/neu, a protein present in one-quarter to half of many types of
cancer, and CMVpp65, a protein present in half of primary brain tumors.
"Our culture method is similar to performing a vaccination procedure
entirely outside the body, and it was successful for all three
proteins," adds Dr. Gendler.
The researchers found that T cells traveling within the bloodstream
naturally remained locked in a resting state unless they were exposed to
natural alarm signals normally triggered only by serious infections.
Once outside the body, however, the T cells could be exposed safely to
such alarm signals to unleash their fighter function. When the T cell
cultures also were exposed to MUC1, HER2/neu, CMVpp65 or other
cancer-associated proteins, it only required three weeks to grow out
natural T cell armies trained to recognize and target cancers expressing
"The cancer-associated proteins we have tested so far already target
the majority of human cancers, and it is likely that this culture
method will extend to many additional proteins present on cancer cells,"
explains Dr. Gendler. Dr. Cohen adds, "We are pleased to help other
investigators implement our culture method for their own
cancer-associated proteins of interest."