Sex differences in innate immune responses to bacterial pathogens

Abstract

Sex-based differences in innate immune responses to bacterial infection are evident in human patients and animal models of disease. Females are less susceptible to the development of bacterial infections and subsequent bacteremia and/or sepsis, while males exhibit a greater incidence of such infections and are more likely to develop fatal sequellae. While the precise effects and mechanisms of action remain to be determined, it is apparent that sex steroid hormones can have direct effects on the expression and function of key bacterial pattern recognition receptors on innate immune cells. Changes in the expression of these receptors are likely to have profound effects on the production of the inflammatory mediators responsible for the lethal nature of septic shock and may underlie the observed sexual dimorphism demonstrated in immune responses to bacterial endotoxins.