New Bacteria-Based Strategy Could Use the Immune System to Attack Cancer Cells

Although the body’s immune system is the first line of defense against infections, some cancers have developed molecular deception techniques to avoid destruction. To combat this problem, an investigator at the University of Missouri may have developed a new bacteria-based therapy to help the immune system get past that deception.

“Normally, your body’s immune cells are constantly on patrol to identify and destroy foreign entities in the body,” said researcher Yves Chabu, an assistant professor in the University of Missouri Division of Biological Sciences, in a press release.

He explained that normal cells put up what he called a “don’t-eat-me” molecular flag that is recognized by immune cells, preventing destruction of normal tissues. When cancers develop the ability to mimic these normal cells, however, Chabu said the immune system fails to recognize the cancer and does not attack it.

Immunotherapies work by blocking the “don’t-eat-me” signal coming from the cancers, allowing the immune system to kill it. Chabu said that although immunotherapies will work for certain types of cancers, prostate cancer is highly immunosuppressive, meaning the cancer’s physical and molecular environments simply overpower the body’s immune system. With the use of a strain of bacteria that is more than 50 years old, however, Chabu said he hopes there might be a solution to this problem.

“Cancers are different in one individual to the next, even when they affect the same tissue,” Chabu said in the press release. “These interpersonal differences contribute to whether or not a particular therapy will effectively kill the cancer and help the patient. The bacteria itself is genetically pliable, therefore it can be genetically modified to overcome patient-specific therapeutic limits.”

In earlier research, investigators developed a genetically distinct and non-toxic strain of salmonella, called CRC2631, to select and kill cancer cells. CRC2631 was derived from a strain of salmonella that had been stored at room temperature for more than 50 years. Chabu’s new research illustrates the ability for CRC2631 to unleash the body’s immune system against prostate cancer.

“Because CRC2631 preferentially colonizes tumor cells, the effect is mainly localized to the tumor,” Chabu explained in the press release. “The use of CRC2631 to design and deliver patient-tailored therapeutics foretells potential in precision medicine, or the ability to tailor a treatment to a specific patient.”

REFERENCE

Killing cancer by unleashing the body’s own immune system [news release]. University of Missouri; January 12, 2021. https://showme.missouri.edu/2021/killing-cancer-by-unleashing-the-bodys-own-immune-system/. Accessed April 20, 2021.