But a new study from the Cancer Therapy & Research Center at The University of Texas Health Science Center at San Antonio shows that some types of immunotherapy previously thought to work only in younger patients can be used to help the elderly, with less toxic effects than many common therapies, if combined in ways that account for age-related changes in the immune system.
"We've shown that immunotherapy for cancer not only works in aged mice, but actually can work better in aged hosts than in young counterparts by capitalizing on the immune changes that happen with age," said Tyler Curiel, M.D., MPH, a professor in the School of Medicine at the Health Science Center and principal investigator of the study, published April 15 in Cancer Research.
As you age, most parts of your body begin to wear out. They keep doing what they're made to do, Dr. Curiel said, but over time, they don't do it as well. The general perception is that the immune system also simply declines with age. "That's really too simplistic," he said. "That's really not the full picture of what's happening."
The body's immune system does weaken with age, but it also changes, and that changes the rules for fighting disease within the body. Dr. Curiel's group started by examining an immune therapy that they previously had shown to work in younger hosts, including cancer patients. It's designed to eliminate regulatory T cells (called Tregs), which are cells that turn off immune responses, allowing cancer to progress. Tregs increase in cancer. In young hosts, the drug turns off Treg activity, allowing the immune system to function better. In older hosts, even though the drug turns off the Tregs, it has no clinical benefit.
Dr. Curiel asked the question why, and in this paper his team explains the answer. In older mice, when the drug turned off the Tregs, the researchers found that another type of immune suppressor cell (a myeloid-derived suppressor cell or MDSC) exploded in number to take the Tregs' place, hampering clinical efficacy. That did not happen in young mice.
The team added a second drug that targets the MDSC, and found that with those tools to help immunity, the older hosts can combat cancer just as well as the younger hosts. Adding the second drug afforded no clinical benefit to young hosts, as their MDSC numbers had not increased.
"We've shown that an aged immune system can combat cancer just as well as a young one if you remove the impediments to successful immunity, which are different that those in younger hosts," Dr. Curiel said. "We've shown that if you test all your immune therapy just in young mice and young people, you'll never learn how it works in older patients — the ones most at risk for cancer. You might conclude that drugs don't work in aged hosts, when they do. But they have to be combined with some help."
After discovering this in melanoma, the researchers then looked at whether the same action held true in colon cancer, a major cancer killer in the elderly.
"The details were different in colon cancer. The bad immune cells that increased in the aged mice and how they were knocked down by the drugs were different than in melanoma," Dr. Curiel said. "But the result was the same — we identified a drug combination that was highly effective in the aged mice."
That means that not only must this strategy be developed with regard to the age of the patient, he said, it also must be specific to the cancer.
"It's a bit complicated, but it's possible to put into practice, and because these approaches could be so much more specific and so much better tolerated than conventional chemotherapy, it is well worth pursuing. We are grateful to the Voelcker Foundation and the Holly Beach Public Library Association for funding this work." he said.
The next step is to test these concepts in an immune therapy clinical trial for elderly patients, which the research team plans to do, Dr. Curiel said.
For current news from the UT Health Science Center, please visit our news release website or follow us on Twitter @uthscsa.
The Cancer Therapy & Research Center (CTRC) at The University of Texas Health Science Center at San Antonio is one of the elite academic cancer centers in the country to be named a National Cancer Institute (NCI) Designated Cancer Center, and is one of only four in Texas. A leader in developing new drugs to treat cancer, the CTRC Institute for Drug Development (IDD) conducts one of the largest oncology Phase I clinical drug programs in the world, and participates in development of cancer drugs approved by the U.S. Food & Drug Administration. For more information, visit www.ctrc.net.
Elizabeth Allen | EurekAlert!
Researchers release the brakes on the immune system
18.10.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn
Norovirus evades immune system by hiding out in rare gut cells
12.10.2017 | University of Pennsylvania School of Medicine
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
18.10.2017 | Materials Sciences
18.10.2017 | Physics and Astronomy
18.10.2017 | Physics and Astronomy