Scientists at the University Medical Center Hamburg-Eppendorf (UKE) have examined mechanisms that lead to decreased disease activity in multiple sclerosis (MS) during pregnancy. They were able to prove that genetic deactivation of a hormone receptor in T cells leads to a loss of protection from MS that normally exists during pregnancy. The hormone receptor is a sensor for the steroid hormone cortisol that occurs in most of the body’s cells. The results of the study have been published by the National Academy of Sciences of the USA (PNAS).
Protective mechanism from auto-aggressive immune cells
Scientists also found that the pregnancy hormone progesterone is able to link up to the cortisol receptor leading to an enrichment of so-called regulatory T cells. They provide a central protective mechanism from auto-aggressive immune cells, which are believed to lead to more MS activity. Prof. Dr. Manuel Friese, Director of the Institute for Neuroimmunology and Multiple Sclerosis at UKE, said: “It has been known for a long time that MS activity decreases during pregnancy. We have been able to learn how this is mediated in molecular terms.”
Therapeutic use of hormones in pregnancy
Dr. Dr. Jan Broder Engler, of the Institute for Neuroimmunology and Multiple Sclerosis at UKE, said: “The T-lymphocytes must be able to react to steroid hormones in the proximity so that the protective mechanism works during pregnancy. Our study indicates that the pregnancy hormone progesterone supports T-lymphocytes in that process. “
Prof. Friese and Dr. Dr. Engler conducted the study in co-operation with Prof. Dr. Petra Arck, of the Clinic for Obstetrics and Prenatal Medicine. Dr. Dr. Engler noted: “So far the therapeutic use of pregnancy hormones in MS has not led to the desired results.” More studies are required to make the protective mechanism during pregnancy available therapeutically.