The aging immune system

Aging of the immune system is marked by a decrease in lymphopoiesis and adaptive immunity, and an increase in inflammation and myeloid pathologies. Are these phenomena related to age-related changes in self-renewing hematopoietic stem cell populations? Here we describe the changes observed during aging in hematopoietic stem cell subpopulations in mouse models. The investigators demonstrate that antibody-mediated depletion of my-CSH in aged mice restores features of a younger immune system, including increases in common lymphocyte progenitors, naive T cells and B cells, while decreasing markers of age-related immune decline.