INTERLEUKIN-6 AND AGING - BLOOD-LEVELS AND MONONUCLEAR CELL PRODUCTION INCREASE WITH ADVANCING AGE AND IN-VITRO PRODUCTION IS MODIFIABLE BYDIETARY RESTRICTION

Interleukin-6 (IL-6) is a multifunctional cytokine that is proving to be a major contributor to the acute phase inflammatory response. IL-6 expression is normally low and serum levels are usually nondetectable in the absence of inflammation. With advancing age, however, serum lev els become detectable and it is proposed that this reflects an age-ass ociated loss in the normal regulation of gene expression for this mole cule. There is also speculation that IL-6 may contribute to the pathog enesis of several diseases that are common in late-life including lymp homa, osteoporosis, and Alzheimer's disease. In this report we demonst rate that plasma levels of IL-6 rise with advancing age in well-select ed healthy elderly people and comparably in old rhesus monkeys. That t his change reflects a primary aging process is suggested by our findin gs in C57BL/6 mice in which the age-associated increase in the in vitr o synthesis of IL-6 is largely prevented by life span-extending dietar y restriction.