MODULATION OF MOUSE SPLEEN NATURAL KILLER (NK) CELL ACTIVITY BY BETA-INTERFERON, INTERLEUKIN-1, AND PROSTAGLANDINS

Abstract

By using CBA/J mice as a source of effector cells and Yac-1 lymphoma line as "target" cells, the natural killer (NK) cell activity was assayed following both in vivo and in vitro immunomodulation [beta-interferon (IF), interleukin-1 (IL-1), indomethacin (IND), prostaglandin-E2 (PGE)]. Only IF/IND and IL-1/IND mixed in vivo led to a significant augmentation of NK cell activity. If exposed in vitro to IF or to IL-1, control group-derived spleen NK cells exhibited increased cytotoxic activity whereas PGE-exposure only was followed by a lower cytotoxic level as expressed both in % cytotoxicity curves and in lytic units 20%/10(7) effector cells. On the other hand, PGE seemed to activate the "nonspecific suppressor" (NSS) cell subset in its inhibitory effect about NK cells as tested in vitro in several NK/NSS cell mixtures at different ratios. IF, but not IL-1 diminished the NSS-cell-induced suppressive activity. Pre-exposure of NK/NSS cell mixtures to IF followed by PGE exposure, did not prevent PGE-dependent NSS cell activation.