The meaning of life lies in sports. Sports can make the cells of the body move, make people look better and healthier. Sports and health are positively related. More and more studies show that exercise has many benefits, helping to prevent cardiovascular and cerebrovascular diseases, diabetes, obesity, improve mood, and even improve the treatment effect of a variety of cancers.
Lactic acid, a metabolite produced during exercise, is also the main source of carbon fuel for many cells. Although lactic acid is associated with cancer growth and immunosuppression, the effects of lactic acid on cancer and immunity are still unclear.
Recently, researchers from the Southwest Medical Center of the University of Texas published a research paper entitled "LATE INCREASES STEMNESS OF CD8+T CELLS TO AUGMENT ANTI-TUMOR IMMUNITY" in the journal "Nature Communications".
This study shows that lactic acid can increase the number of tumor infiltrating CD8+T cells and enhance anti-tumor immunity. This discovery is expected to be used to develop new strategies to enhance the anti-tumor effect of cancer immunotherapy.
In this study, the researchers injected lactic acid subcutaneously into mice with colon cancer or melanoma, and injected glucose solution into the control group.
The results showed that the growth of tumor in mice treated with lactic acid was significantly reduced, compared with the effect of glucose on tumor.
Since then, researchers have used genetic engineering to modify mice to make them lack T cells, and conducted the same experiment on mice. However, no anti-tumor benefit was found this time, indicating that lactic acid seems to be playing its role through this immune cell population.
Lactic acid enhances anti-tumor immunity through CD8+T cells
In subsequent studies, researchers found that lactic acid alone could not completely eliminate tumors. However, when researchers added a commonly used immunocheckpoint inhibitor, about half of the mice 'tumors completely disappeared.
In addition, the researchers also found that lactic acid significantly improved the effect of anti-cancer vaccine and the anti-cancer response of cultured T cells injected into tumor mice.
Further single cell RNA sequencing analysis showed that lactic acid treatment significantly increased the number of infiltrating CD8+T cells in the tumor.
Compared with the mice without lactic acid therapy, the T cells of the mice receiving lactic acid therapy expressed more genes related to stem cell like T cells, while the number of genes related to depletion markers was less, making them more effective in fighting cancer.
Lactic acid therapy increases stem cell like CD8+T cells in tumors
The researchers said the results showed that lactic acid could be used to supplement existing immunotherapies, such as immunocheckpoint inhibitors, cancer vaccines and CAR-T cell therapies.
Research also shows that exercise will increase the level of lactic acid, which may have a protective effect on cancer, or may also enhance the immune system to fight cancer.
To sum up, this study reveals the role of lactic acid in anti-tumor immunity. Lactic acid can enhance anti-tumor immunity. This discovery is expected to be used to develop new strategies to enhance the anti-tumor effect of cancer immunotherapy.
Paper link:
https://doi.org/10.1038/s41467-022-32521-8
Source:
https://www.medsci.cn/article/show_article.do?id=f3aae40765fd
