K. Uyemura et al., CROSS-REGULATORY ROLES OF INTERLEUKIN (IL)-12 AND IL-10 IN ATHEROSCLEROSIS, The Journal of clinical investigation, 97(9), 1996, pp. 2130-2138
T cell cytokines are known to play a major role in determining protect
ion and pathology in infectious disease. It has recently become clear
that IL-12 is a key inducer of the type 1 T cell cytokine pattern char
acterized by production of IFN-gamma. Conversely, n-10 down-regulates
IL-12 production and type 1 cytokine responses. We have investigated w
hether IL-12 and IL-10 might be involved in a chronic inflammatory rea
ction, atherosclerosis. In atherosclerotic plaques, we found strong ex
pression of IFN-gamma but not IL-4 mRNAs as compared to normal arterie
s. IL-12 p40 mRNA and IL-12 p70 protein were also found to be abundant
in atherosclerotic plaques. IL-12 was induced in monocytes in vitro i
n response to highly oxidized LDL but not minimally modified LDL. The
cross-regulatory role of IL-10 was indicated by the expression of IL-1
0 in some atherosclerotic lesions, and the demonstration that exogenou
s rIL-10 inhibited LDL-induced IL-12 release. These data suggest that
the balance between IL-12 and IL-10 production contributes to the leve
l of immune-mediated tissue injury in atherosclerosis.