Abstract
Chemokine KC has been considered to be a murine homologue of human GRO/MGSA and
was identified as chemoattractant for monocytes and neutrophils. This study
examined the expression of KC mRNA in thioglycollate-elicited mouse peritoneal
macrophages that were stimulated in vitro with Candida albicans (CA). Also
examined were the inhibitory effects of IL-10 on the CA-induced expression of KC
gene by Northern blot analysis. CA was found to induce chemokine gene expression
in a gene-specific manner, CXC chemokine IP-10 mRNA expression was not detected
in CA-stimulated macrophages. Maximum KC mRNA expression was observed
approximately 2 hr after adding CA. The inhibitory action of IL-10 to CA-induced
KC mRNA expression on mouse peritoneal macrophages was independent on
concentration and stimulation time of IL-10 and was observed approximately one
hour after adding IL-10 and CA simultaneously. IL-10 produced a decrease in the
stability of KC mRNA, and CA-stimulated macrophages with cycloheximide blocked
the suppressive effect of IL-10. These results suggest that CA also induces
chemokine KC from macrophages, and IL-10 acts to destabilize CA-induced KC mRNA
and de novo synthesis of an intermediate protein is a part of the IL-10
suppressive mechanism.