Endometriosis tricks the immune system in a way similar to cancer

Endometriosis is a benign, chronic disease, in which tissue similar to the lining of the uterus attaches to places in the body other than inside the uterus and causes pain. Emma Björk, Department of Clinical Sciences, has shown in her research that endometriosis secretes so-called exosomes that trick the immune system into inactivity in the same way that cancer does. Endometriosis also secretes something called cytokines, which produce an immune response that counteracts the removal of the endometriotic cells.

Emma Björk, Department of Clinical Science.

ImageHans Karlsson

"It is known that the immune system's so-called natural killer cells do not function optimally in endometriosis and therefore do not kill the endometriotic cells, but it has not been known why," says  Emma Björk.

These exosomes carry molecules that inhibit the activity of natural killer cells and increase programmed cell death in active immune cells. These two mechanisms give the endometriotic tissue the opportunity to both persist and grow in the body. Similar experiments were carried out in ovarian cancer, and it turned out that ovarian cancer also secretes exosomes with molecules that inactivate natural killer cells. The thesis also investigated the expression of cytokines, i.e. small proteins that are used for communication between cells. Among other things, an immunosuppressive cytokine response was observed, and microscopy showed an increased number of immune cells of a type that inhibits the activity of natural killer cells in the endometriotic tissue.

The thesis demonstrates several mechanisms affecting the function of natural killer cells in endometriosis. This new knowledge contributes to the understanding of how the disease can arise and further develop. Hopefully, the results can contribute to new treatments and diagnostic possibilities.

"At present, it takes several years to be diagnosed, and the treatments available often cause side effects. Exosomes will probably lead to ways to diagnose many different diseases in the future more easily," says Emma Björk.

Emma Björk grew up in Örnsköldsvik and received her medical degree at Umeå University. She has been a gynecologist for almost 20 years and completed her further education as a gynecologist at the hospital in Örnsköldsvik, where she continues to work with a focus on endometriosis patients. For five years, Emma worked at the Centre for Obstetrics and Gynecology in Umeå, where she began her doctoral studies.

On Friday 14 June, Emma Björk, Department of Clinical Sciences, Obstetrics and Gynecology, at Umeå University, will defend her thesis titled: “Immunosuppressive mechanisms in endometriosis – a focus on the role of exosomes”. The dissertation will take place at 09.00 in lecture hall Betula, destination L0, building 6M, floor 0, NUS, and via link.