Myeloid-Derived Suppressor Cells in Aged Humans

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells whose
immunosuppressive activities contribute to cancer and other diseases. MDSCs
appear to increase with age, and this presumably contributes to immunosuppression
and the increased incidence of certain diseases. Why MDSCs increase with
age is not entirely clear. Herein we present evidence that MDSC expansion is due
in part to age-related changes in hematopoiesis, including the acquisition of
mutations that favor myelopoiesis, which are compounded by changes in the
aging microenvironment that favor the production of MDSCs.