Health

Listeria-based boosters improve vaccine protection against recurrent colon cancer

Credit: AIXabay / CC0 public domain

Colorectal cancer, pancreatic cancer, esophageal cancer, and gastric cancer (some of the most deadly types of cancer) have a high recurrence rate of cancer recurrence even after successful surgery or radiation therapy.

To combat these refractory cancers, researchers at Thomas University Jefferson, led by Dr. Adam Snook, an associate professor of pharmacology and experimental treatment, instead used what was essentially a vaccine. To train the patient’s immune system, cancer From coming back. Vaccines usually use either a modified virus or a modified bacterium.

New research from Dr. Snook’s lab Animal model Using the viral and bacterial vaccine approaches together is safer and much more effective in the fight against cancer than using either approach alone.

“The vaccine platform is not unique,” ​​says Dr. Snook, a researcher at Jefferson Health at the Sidney Kimmel Cancer Center. “But no one puts them together Combination vaccineStill, it was then that we saw the immune response actually take off. “

In a previous study, Dr. Snook and his team worked as a cancer vaccine backbone to train a patient’s immune system to identify and attack a unique colorectal cancer molecule called GUCY2C (pronounced GUCY2C). We used a modified version of a common virus known as adenovirus). This vaccine treatment called Ad5.F35-GUCY2C Currently in Phase II clinical trials..

The adenovirus-based vaccine approach stimulates a patient’s highly effective immune response, but the effect is not persistent. Vaccines often require additional doses to produce the best possible immune response. However, once introduced, the body becomes familiar with adenovirus and, as a result, does not produce the same type of immune response at additional doses. The body needed another type of booster for the primed immune system to continue to deliver cancer-fighting immunity.

Dr. Snook and his team turned to a bacterial-based vaccine approach using a modified format. Listeria monocytogenes It cannot cause illness in mice or humans. Unlike the adenovirus platform Listeria approach I’m not good at creating an immune response, but even with additional doses, it’s good at boosting the response.

“I’m really good at infecting certain types of immune cells, called antigen-presenting cells, which are important for producing an effective immune response against cancer,” says Dr. Snook.

At that time, they came up with the idea of ​​combining the two platforms. When researchers first stimulated the animal’s immune system with an adenovirus-based vaccine and then enhanced it with a Listeria-based vaccine. Immune cells That attack cancer cell I shot more than 15 times with the mouse.

In a model of recurrent colorectal cancer that has spread beyond the colon to parts of the body, the combination vaccine approach reduced animal metastasis and increased survival, researchers said in the journal June 23. Reported to npj vaccine..

“The combination of these two platforms actually worked well. It’s much better than creating either platform alone. Immune response It targets cancer, “says Dr. Snook.

Vaccine strategies have also shown that they do not cause toxicity or inflammation in animals and that treatment is well tolerated without unintended effects.

The findings laid the foundation for the first time to see if this combination could prevent the patient from recurring cancer. The Pentagon recently awarded Dr. Snook and his colleague, Dr. Bavar Basir, MD, an assistant professor of oncology at Jefferson, a “team science” grant to incorporate the combination vaccine approach into Phase I clinical trials. Researchers are currently working on the production of the vaccine and will begin enrolling patients next year.

The one-two hit of the combo vaccine platform also affects other cancers and diseases such as HIV and malaria. vaccination It was difficult to make a strategy.

“Such a platform is also very effective against these illnesses,” says Dr. Snook.


Small changes make cancer vaccines more effective in animal experiments


For more information:
Prime boost immunization with chimeric adenovirus (Ad5.F35) and Listeria vector is a safe and effective strategy for cancer immunotherapy. npj vaccine (2022). DOI: 10.1038 / s41541-022-00483-z

Quote: Listeria-based booster is recurrent colon cancer (2022) obtained on June 23, 2022 from https: //medicalxpress.com/news/2022-06-listeria-based-booster-vaccine-recurring-colon.html. Improves vaccine protection against (June 23, 2014)

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