MIT and Harvard Build “Invisible” Immune Cells That Obliterate Cancer

MIT and Harvard scientists have created engineered CAR-NK cells that can hide from the immune system and more effectively destroy cancer.

The cells are designed to suppress immune-rejection signals and enhance tumor-killing power. Tested in humanized mice, they wiped out cancer while avoiding dangerous immune reactions.

A Major Breakthrough in Immune Engineering

Scientists have recently developed a powerful new approach to fighting cancer using specially engineered immune cells called CAR-NK (natural killer) cells. These cells function much like CAR-T cells, which can be customized to seek out and destroy cancer, but rely on a different type of immune cell as their foundation.

Researchers at MIT and Harvard Medical School have now designed an improved version of CAR-NK cells that are far less likely to be attacked by a patient’s own immune system, a major obstacle in current cell-based therapies.

This breakthrough could also open the door to “off-the-shelf” CAR-NK treatments that doctors can administer immediately after diagnosis, eliminating the long preparation period required for most personalized cancer immunotherapies. Conventional CAR-NK and CAR-T cell production often takes several weeks.

Safer, Stronger Cancer Killers

“This enables us to do one-step engineering of CAR-NK cells that can avoid rejection by host T cells and other immune cells. And, they kill cancer cells better and they’re safer,” says Jianzhu Chen, an MIT professor of biology, a member of the Koch Institute for Integrative Cancer Research, and one of the senior authors of the study.

When tested in mice with human-like immune systems, the newly engineered cells successfully eliminated most cancer cells while avoiding detection and destruction by the host immune system.

Rizwan Romee, an associate professor of medicine at Harvard Medical School and Dana-Farber Cancer Institute, also served as a senior author of the study, published today (October 8) in Nature Communications. The lead author is Fuguo Liu, a postdoctoral researcher at the Koch Institute and a research fellow at Dana-Farber.

How NK Cells Naturally Hunt Cancer NK cells are a critical part of the body’s natural immune defenses, and their primary responsibility is to locate and kill cancer cells and virus-infected cells. One of their cell-killing strategies, also used by T cells, is a process called degranulation. Through this process, immune cells release a protein called perforin, which can poke holes in another cell to induce cell death.

To create CAR-NK cells to treat cancer patients, doctors first take a blood sample from the patient. NK cells are isolated from the sample and engineered to express a protein called a chimeric antigen receptor (CAR), which can be designed to target specific proteins found on cancer cells.

Then, the cells spend several weeks proliferating until there are enough to transfuse back into the patient. A similar approach is also used to create CAR-T cells. Several CAR-T cell therapies have been approved to treat blood cancers such as lymphoma and leukemia, but CAR-NK treatments are still in clinical trials.

Ref: MIT and Harvard Build “Invisible” Immune Cells That Obliterate Cancer