Influence of age and caloric restriction on macrophage IL-6 and TNF production

Aging is correlated with a plethora of immunological changes resulting in both decreased immunity to exogenous antigens and increased autoreactivity. Immunosenescence is generally believed to primarily affect the B- and T-cell compartments, leaving macrophage (M phi) function relatively intact. However, several recent reports show diminished presentation of certain antigens and decline in interleukin 1 (IL-1) production by aged M phi s suggesting the need for more extensive assessment of M phi function. In the present study we demonstrate that aged murine M phi s show diminished IL-6 and TNF production. In addition, we show that dietary caloric restriction, a regimen which extends life span and improves many immunological functions, has no effect on the declining TNF production.