Oestrogen and immunomodulation: new mechanisms that impact on peripheral and central immunity.

The regulation of the immune response to infection or tissue damage is a complex interplay of multiple factors, but it has long been recognised that steroid hormones can exert powerful modulatory effects at all levels of the innate and adaptive immune systems. Although most attention has been paid to glucocorticoids given their widespread clinical use, it is becoming increasingly clear that sex steroid hormones, and in particular the principle female sex steroid oestrogen, exerts potent effects upon the immune response. In this review, we will discuss the latest findings on the impact of oestrogen upon various cellular components of the immune system, and how this hormone can offer new opportunities to pharmacologically harness the immune response.