The link between bundles given off by tumour cells known as extracellular vesicles and the immune response to tumours has been established, suggesting a new way to help the body attack tumours.
CD4+ regulatory T (Treg) cells play a critical role in regulating the immune response, helping to prevent autoinflammatory and inflammatory diseases. But they can also suppress the immune response to cancer, and high numbers of Treg cells in and near tumours have been linked with poor prognosis.
Now, six researchers, all at the University of Tsukuba in Japan, have discovered how the activation of Treg cells is regulated near tumours.
They found that mice lacking the inhibitory immunoreceptor CD300a on their dendritic cells had higher numbers of Treg cells in tumours. Furthermore, the team showed that extracellular vesicles from tumours bind to CD300a, preventing them from activating Treg cells.
Drugs that boost the expression levels of CD300a could thus help the body better fight cancer.