Tuesday, August 27, 2013

FAQ: Why is there a gender bias in autoimmune diseases?

It has been known for some time that females can mount a more powerful immune response than males. While this is usually beneficial, it also means that females are more susceptible to auto-immune diseases such as type 1 diabetes. By definition an autoimmune disease is one in which your immune system identifies your cells as foreign and mounts an attack to eliminate them. In type 1 diabetes insulin-producing cells of the pancreas are destroyed leading to increased blood glucose.

The structure of insulin
A recent paper in the journal Immunity entitled: 'Gender Bias in Autoimmunity Is Influenced by Microbiota' indicates that both microbes and hormones play a role in gender bias for type 1 diabetes. The authors from The University of Chicago employed several different mouse strains that were grown under various conditions. They found that mice grown in germ-free conditions did not exhibit gender bias and that mice with some types of defined microbiota, that were overrepresented in male mice, did support gender bias. Furthermore they show that androgens, male hormones, influence gut microbiota and could work as a positive-feedback mechanism that contributes to the gender bias of autoimmune disease.