Scientists have made a significant discovery indicating that a weakened virus can effectively eradicate cancer in mice. Moreover, mice treated with this virus showed increased resistance to developing tumors later in life. Importantly, the weakened virus was found to be safe and effective in immunosuppressed mice, which is crucial for cancer patients undergoing various treatments that weaken their immune systems.
· Weakened virus helps eliminate melanoma and colon cancer in mice
· Therapy is effective in treating and even preventing cancer
· Virus raises ‘red flag’ on t rnrnRumors are circulating about a virus that can activate immune cells to attack cancer. Northwestern Medicine researchers have found that a weakened virus can effectively eliminate cancer in mice and provide resistance to tumor development later in life. The virus, called lymphocytic choriomeningitis virus (LCMV), remains safe and effective even in mice with suppressed immune systems, a crucial discovery for cancer patients undergoing chemotherapy and other treatments that weaken the immune system. This viral-based therapy demonstrates both safety and effectiveness, offering hope for the future of cancer treatment.The effectiveness of this therapy was demonstrated even in an immunosuppressed host,” stated Pablo Penaloza-MacMaster, an assistant professor of microbiology-immunology at Northwestern University Feinberg School of Medicine. He added, “Mice that lacked killer T cells and B cells still showed a positive response to the treatment.”
Northwestern scientists conducted experiments in various tumor models, such as melanoma and colon cancer. They found that injecting tumor-bearing mice with the virus led to tumor shrinkage and increased survival rates.
The findings of the study were published on June 11 in The Journal of Clinical Investigation.“LCMV sparks a strong immune response, but it can result in illness, especially in transplant patients,” explained Penaloza-MacMaster. “Through molecular biology, it is possible to weaken the virus and make it less harmful for use as a safe therapy, while still maintaining its ability to trigger an immune response. Another advantage is that it seems that the same LCMV treatment can be used for different types of cancer.”
Currently, oncolytic viruses like herpes are used to treat certain types of cancer due to their ability to destroy cancer cells. However, these treatments are not effective for some tumors and raise safety concerns, particularly in transplant patients.ally in immunosuppressed patients, highlighting the necessity for safer alternatives, Penaloza-MacMaster mentioned.
Aside from clearing the tumors, the treatment also aided in preventing future cancer in these mice. Healthy mice that received the LCMV therapy initially were more resilient to developing tumors later in life.
This phenomenon could be attributed to a poorly understood biological process called “trained immunity.” Trained immunity occurs when a previous infection boosts the immune system’s capacity to react to different diseases in the future. For instance, research has demonstrated that children who were vaccinated against tuberculosis (TB) vaccine may offer wider protection against various microorganisms, not just TB itself. This is unlike other vaccines, like the SARS-CoV-2 vaccine, which mainly provides protection against specific viruses.
“This treatment could potentially offer broader immune protection, helping the body defend against different diseases beyond the intended target,” explained Penaloza-MacMaster, a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University.
The next phase of this research involves testing the approach on dogs with sarcoma in collaboration with.Dr. Seth Pollack, the Steven T. Rosen Professor of Cancer Biology at Feinberg and director of the Sarcoma Program at Lurie Cancer Center, is working on a therapy that could potentially be used to treat cancer in both dogs and humans. If successful in dogs, the next step would be to launch a clinical trial for humans.
The therapy involves using a virus to treat tumors. Tumors have a way of evading the immune response, but injecting the virus into the tumor can alert the immune system to the presence of the tumor. This is because the virus acts as a signal to the immune system, indicating that there is an intruder in the body.
In experiments with immunosuppressed mice, it was found that they had no T cells, B cells or macrophages, which are all key components of the immune system.The virus was able to activate alternative immune pathways to fight the cancer, even though crucial immune cells were absent. Interferons, which are molecules that signal the presence of an intruder and help rally the body’s defense mechanisms, played a key role in this process.
Additional authors from Northwestern University include Young Rock Chung and Bakare Awakoaiye as the first authors, as well as co-authors Tanushree Dangi, Nahid Irani, and Slim Fourati.
This work was supported by a grant DP2DA051912 from theNational Institute on Drug Abuse of the National Institutes of Health, the American Cancer Society, and a pilot grant from the Lurie Cancer Center are involved.
