Researchers from Harvard Medical School and the Broad Institute conducted one studio That shows how the composition of the intestinal microbiota can affect the effectiveness of immune therapies for cancer. The study, published in the journal Nature, identified specific microbial molecules and their mechanisms of interaction with immune cells they may help improve the immune system’s response to immune therapy for cancer. Cancer uses a trick to keep the immune system from destroying its cells, by making tumor cells express two proteins called PD-L1 and PD-L2.
These proteins interact with another protein called PD-1, which slows down the action of T cells. Immune therapies for cancer that block this interaction can help T cells destroy cancer cells.
Interaction between microbiota and immune cells
Scientists have found that Gut microbiota composition may influence the efficacy of immune cancer therapies. In particular, they have identified a microbial molecule called RGMb which works together with PD-L2 to suppress T cells. Further analysis showed that lThe interaction between RGMb and PD-L2 depends on the composition of the gut microbes and that some intestinal bacteria can affect the levels of both molecules.
Immune therapies for cancer and gut microbiota
In mice with cancer, bacteria in the gut affected their response to immune therapy. Mice that had specific gut bacteria had much lower RGMb levels on their T cells than animals with no bacteria in their gut, and they responded well to anti-PD-L1 or anti-PD-1 therapy.
In contrast, mice with no bacteria in their guts did not respond to these treatments and had higher levels of RGMb on their T cells, especially those that were inside the tumor.. Similarly, mice with gut bacteria from patients who hadn’t responded well to therapy had higher levels of RGMb, suggesting that patients with high levels of RGMb on their T cells may have a weaker response to immune therapy.
Blocking the activity of PD-L2 or RGMb was sufficient to maintain the antitumor activity of T cells and ensure a good response to anti-PD-L1 and anti-PD-1 therapy. Additionally, blocking PD-L2 activity led to a strong antitumor response in mice treated with another form of immune therapy called dendritic cell therapy. This finding suggests that blocking PD-L2 activity could enhance response to many types of immune therapies for cancer.
Intestinal microbes as regulators of the immune response
Researchers have found that a bacterium called C. cateniformis may help make immune therapy for cancer in mice more effective.
While there are many other bacterial species in the human gut that could have the same effect, this finding suggests that specific microbial molecules could be used to enhance the immune system’s ability to fight cancer.
This new type of drugs, called small molecule microbial drugs, are generally taken in the form of pills, while immunotherapy is administered via intravenous infusion of antibodies.
The importance of the microbiota
The study showed the importance of gut microbes in the response to cancer immune therapy by identifying specific microbial molecules that can be exploited to improve cancer treatment.
The discovery of the interaction between microbiota and immune cells represents a significant step forward in the fight against cancer.
While there are other ways in which the microbiota can influence antitumor immunity and cancer immunotherapy, the potential of these new drugs to complement or replace traditional antibody-based immunotherapy offers on paper the promise of more effective treatments. cheap and accessible.
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