INHIBITION OF INTERFERON-GAMMA-INDUCED MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-I EXPRESSION BY CERTAIN OLIGODEOXYNUCLEOTIDES

We report that certain oligonucleotides are capable of inhibiting cell surface induction of the major histocompatibility complex class I (MH C-I) proteins by interferon-gamma in K562 cells. The inhibition by oli godeoxynucleotide I 5' GGG GTT GGT TGT GTT GGG TGT TGT GT-RNH(2) is do se-dependent, with an EC(50) 24 hr after dosing of approximately 4 mu M for 800 U/ml interferon-gamma. The reverse complement II 5' AC ACA A CA CCC AAC ACA ACC AAC CCC-RNH(2) did not show activity. Oligodeoxynuc leotide I inhibits induction of MHC-I by interferon gamma, but does no t inhibit induction by either interferon-alpha or interferon-beta. Fou r other oligodeoxynucleotides were also evaluated, and three showed ac tivity against interferon-gamma at 25 mu M.