Researchers have discovered a novel method for reversing immune suppression in tumors

Oct, 2021 - By SMI

Researchers demonstrated that the club cell factors inhibit very strong immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs), which tumors frequently engage to help them avoid anticancer immune responses in a mouse model.

Malignant tumors can boost their ability to live and expand by reducing antitumor immune cells in the area, but a new study led by New York-Presbyterian and Weill Cornell Medicine has discovered a mechanism to counteract this immunosuppressive action. The researchers discovered a group of anti-immunosuppressive substances that are released by club cells, which coat the lungs' airways. They demonstrated that such club cell factors restrict highly effective immunosuppressive cells known as myeloid-derived suppressor cells (MDSCs), which tumors often recruit to help them avoid antitumor immune responses.

The suppression of MDSCs resulted in an increase in antitumor T cells at the tumor site, significantly improving the efficacy of U.S. food and drug administration-approved PD1 immunotherapy. The study is part of a larger effort in recent years to figure out how to use the immune system to fight cancer. Treatments such as "immune checkpoint inhibitors" (ICIs) have resulted from this endeavor, which partially reverses tumor immunosuppressive effects. Oncologists have recently discovered that ionizing radiation, which has long been a routine treatment for many tumors, might further reverse immune suppression and hence improve the efficiency of ICI treatments.

Researchers initially established that this impact peaked at a moderate dosage of radiation, causing the proportion of ICI-treated mice that remained tumor-free to the end of the two-month period of observation to quadruple, to 40%. the researchers discovered that the radiation has this effect via activating and encouraging the proliferation of lung-resident club cells, which are recognized to maintain and repair fragile airway linings, in part by lowering inflammation.

The researchers are now trying to figure out which chemicals in their club cocktail are most crucial for suppressing MDSCs and improving cancer treatments. They also want to see if these club cell chemicals can stop MDSCs from developing in other tumors.