American scientists discovered that immune cells created during severe Covid-19 infection can cause cancer tumors to shrink.
The study was published November 15 in the Journal of Clinical Investigation. Genetic information from the virus that causes Covid-19 causes the immune system to create special cells with anti-cancer properties. These cells, called monocytes, help shrink some tumors in mice.
According to Dr. Ankit Bharat, Chief of Thoracic Surgery at Northwestern Medicine and lead author of the study, normally, cancer spreads when monocytes gather at the tumor site. Tumor cells then convert these white blood cells into cancer-friendly cells. Monocytes then help protect cancer cells from the immune system, allowing tumors to grow.
“They essentially form a protective layer around cancer cells, shielding them from attack by the body’s immune system,” Dr. Bharat said.
Previous research has shown that some infectious diseases, such as Covid-19, can cause changes in the properties of monocytes. Dr. Christopher Ohl, an infectious disease specialist at Atrium Health Wake Forest Baptist, said these “new” monocytes are trained to specifically target the virus, to coordinate the immune response more effectively. .
Dr. Bharat and colleagues found that the tumors of some patients with severe Covid-19 had shrunk. Therefore, they analyzed blood samples from cases and discovered that monocytes produced after virus infection still retain a special receptor that binds well to the RNA chain of Covid-19.
Electron microscope image of the nCoV virus that causes Covid-19. Image: Adobe Stock
Scientists continue to conduct research on mice with stage 4 melanoma, lung cancer, breast cancer and colon cancer. Lab mice are given a drug to create monocytes that begin to develop. mimic the immune response when infected with Covid-19. As a result, all four cancer tumors shrank. Scientists found that modified monocytes have anti-cancer properties and are not transformed by tumors into “cancer-friendly” cells that shield them.
Instead, the monocytes migrated to the site of the mice’s tumors – something most immune cells do not do. Once near the tumor, monocytes activate natural killer cells, Dr. Bharat said.
Dr. Bharat suggests that this mechanism may work in humans against other types of cancer because it disrupts the way tumors spread throughout the body. According to him, Covid-19 vaccines on the market are unlikely to activate this mechanism, because they do not use the same RNA sequence as the virus. However, experts can develop more drugs and vaccines to treat advanced forms of cancer that do not respond to immunotherapy.
According to Yibin Kang, a professor of molecular biology at Princeton University, immunotherapy is 20% – 40% effective. Treatment fails when the patient’s body cannot produce enough T cells, which have the function of destroying cancer.
“The problem with this therapy is that it depends on T-cell immunity,” Dr. Kang explains.
Dr. Kang said the new research is very promising, because it further suggests a way to selectively kill tumors, independent of T cells. Dr. Ohl agreed with this statement, saying that magnetic therapy Covid-19 is a “roundabout”, bypassing the traditional barriers encountered in immunotherapy. However, more clinical trials are needed to see if this mechanism is similarly effective in humans.