It is well known that being stressed increases our susceptibility to infections by impairing the function of our immune system, but the molecular links between stress and diminished immune function have not been determined.
However, Peter Elias and colleagues at UCSF, have now characterized a mechanistic link in mice between psychological stress and increased susceptibility to skin infections.
Mice subjected to conditions of psychological stress were found to be more susceptible to group A Streptococcus pyogenes skin infections than mice housed under normal conditions.
This was associated with decreased expression of antimicrobial peptides by the epidermis of the skin.
Further analysis revealed that psychological stress induced the increased production of glucocorticoids and that this inhibited the synthesis of fats in the epidermis of the skin and decreased the secretion of vesicles that contain antimicrobial peptides.
As indicated by the authors and Andrzej Slominski from the University of Tennessee, Memphis, in an accompanying commentary, these data lead to the suggestion that the immune function of the skin might be improved in individuals who are stressed by inhibiting the action of glucocorticoids.