Tumours hide out from the immune system by mimicking lymph nodes

Tumours hide out from the immune system by mimicking lymph nodes

A new mechanism explaining how tumours escape the body's natural immune surveillance has recently been discovered at EPFL (Ecole Polytechnique Fédérale de Lausanne) in Switzerland. The study shows how tumours can create a tolerant microenviroment and avoid attack by the immune system by mimicking key features of lymph nodes.

The discovery, published in Science and in Science Express, underscores the role of the lymphatic system in cancer and may open up new possibilities for cancer treatment.

"The tumour tricks the body into thinking it is healthy tissue," says lead author Melody Swartz, head of the Laboratory of Lymphatic and Cancer Bioengineering (LLCB) and EPFL professor. Swartz and her team set out to understand how immune tolerance is induced by tumours, allowing them to progress and spread.

The researchers from EPFL concentrated their efforts on a certain protein that is normally present in healthy lymph nodes to attract T cells and program them to perform vital immune functions. They found that some tumours can secrete this protein to transform the outer layer of the tumour into lymphoid-like tissue.

This outer layer then attracts and effectively re-programs the T cells to recognise the tumour as friend not foe, resulting in a tumour that goes undetected by the immune system.

Since most tumours progress only if they have escaped the immune system, this new understanding of one mechanism by which the tumour can bypasses or hides from immune defenses is an important step towards future cancer therapies.