Aging and innate immunity in the mouse: impact of intrinsic and extrinsic factors

Aging affects every innate immune cell, including changes in cell numbers and function. Defects in the function of some cells are intrinsic, whereas for other cells, defects are extrinsic and possibly the consequence of the complex interactions with other cell types or the environmental milieu that is altered with aging. Abnormal function contributes to worsened outcomes after injury or infection and leads to diseases observed in the elderly. Knowing the mechanisms responsible for the aberrant function of innate immune cells might lead to the development of therapeutic strategies designed to improve innate immunity in aged individuals. Herein, advances in the field of innate immunity and aging with a focus on neutrophils, macrophages and dendritic cells in laboratory animals are discussed.