Activation of microglia and astrocytes by CpG oligodeoxynucleotides

Bacterial DNA and synthetic oligodeoxynucleotides (ODN) containing unmethyl ated CpG motifs stimulate cells of the immune system to secrete a variety o f cytokines and chemokines. This function can be carried out by microglia a nd astrocytes in the CNS. To evaluate the effect of CpG ODIN on microglia a nd astrocytes, purified cells were isolated and cultured in vitro. CpG ODN rapidly up-regulated their production of IL-1 beta, IL-6, IL-12, TNF alpha, MIP-I alpha and/or MIP-1 beta. In vivo, systemically administered CpG ODIN up-regulated the expression of mRNA encoding cytokines and chemokines in n ormal mouse brain. These findings suggest that CpG ODN can directly activat e immune cells of the CNS. NeuroReport 12:3029-3032 (C) 2001 Lippincott Wil liams & Wilkins.