"Injecting the flu vaccine into a tumor gets the immune system to attack it"
"For more detailed tests, the researchers moved to mice, using melanoma cells that can form tumors when transplanted into the lungs of the mice. These model systems often respond to treatments that don't end up working in humans, so the results have to be treated with appropriate caution. Still, they can be a valuable way of understanding the biology of the immune response here.
The use of melanoma cells is informative, as these cells cannot be infected by the influenza virus. So this system also provides a test of whether the tumor cells themselves have to be infected in order to increase the immune response to them. Apparently they do not. Having an active influenza virus infection reduced the ability of the melanoma cells to establish themselves in the lung. The effect isn't limited to the location of the infection, though, as tumors in the lung that wasn't infected were also inhibited. The effects were similar when breast cancer cells were placed into the lung, as well.
All of this is consistent with the immune stimulation provided by a pathogen. The stimulation causes a general activation of the immune system that releases it from limits on its activity that prevent it from attacking tumor cells. But does it require an actual infection? To find out, the researchers used a flu virus that had been inactivated by heat treatment. Normally, heat treating a virus is used to create a control for an effect that needs an active virus. But here, it turned out to be another experiment, as the heat-treated virus was also able to work just as effectively as the live virus.
This isn't entirely surprising, given that inactive viruses are often used as vaccines and thus clearly can stimulate the immune system. But that, in turn, suggested another experiment: would vaccines actually work? To find out, the researchers obtained this year's flu vaccine and injected it into the sites of tumors. Not only was tumor growth slowed, but the mice ended up immune to the flu virus.
Oddly, this wasn't true for every flu vaccine. Some vaccines contain chemicals that enhance the immune system's memory, promoting the formation of a long-term response to pathogens (called adjuvants). When a vaccine containing one of these chemicals was used, the immune system wasn't stimulated to limit the tumors' growth.
This suggests that it's less a matter of stimulating the immune system and more an issue of triggering it to attack immediately. "
https://arstechnica.com/science/2019/12/...attack-it/
"For more detailed tests, the researchers moved to mice, using melanoma cells that can form tumors when transplanted into the lungs of the mice. These model systems often respond to treatments that don't end up working in humans, so the results have to be treated with appropriate caution. Still, they can be a valuable way of understanding the biology of the immune response here.
The use of melanoma cells is informative, as these cells cannot be infected by the influenza virus. So this system also provides a test of whether the tumor cells themselves have to be infected in order to increase the immune response to them. Apparently they do not. Having an active influenza virus infection reduced the ability of the melanoma cells to establish themselves in the lung. The effect isn't limited to the location of the infection, though, as tumors in the lung that wasn't infected were also inhibited. The effects were similar when breast cancer cells were placed into the lung, as well.
All of this is consistent with the immune stimulation provided by a pathogen. The stimulation causes a general activation of the immune system that releases it from limits on its activity that prevent it from attacking tumor cells. But does it require an actual infection? To find out, the researchers used a flu virus that had been inactivated by heat treatment. Normally, heat treating a virus is used to create a control for an effect that needs an active virus. But here, it turned out to be another experiment, as the heat-treated virus was also able to work just as effectively as the live virus.
This isn't entirely surprising, given that inactive viruses are often used as vaccines and thus clearly can stimulate the immune system. But that, in turn, suggested another experiment: would vaccines actually work? To find out, the researchers obtained this year's flu vaccine and injected it into the sites of tumors. Not only was tumor growth slowed, but the mice ended up immune to the flu virus.
Oddly, this wasn't true for every flu vaccine. Some vaccines contain chemicals that enhance the immune system's memory, promoting the formation of a long-term response to pathogens (called adjuvants). When a vaccine containing one of these chemicals was used, the immune system wasn't stimulated to limit the tumors' growth.
This suggests that it's less a matter of stimulating the immune system and more an issue of triggering it to attack immediately. "
https://arstechnica.com/science/2019/12/...attack-it/
