In vivo priming effects of interferon-beta ser on NK activity of peripheral blood mononuclear cells in @entity5 XXXX .

@entity1 @entity2940 @entity5 @entity3053 @entity4071 @entity2391 @entity379
Natural killer (NK) activity was assayed in fresh peripheral blood mononuclear cells (PBMs) from @entity5 @entity1 receiving @entity2391 ser. @entity1 received a single intravenous injection of @entity2391 ser (90 x 10(6) IU m-2) on alternate days for 2 weeks, followed by a higher dose (180 x 10(6) IU m-2) on the same schedule. PBM NK lysis of K562 target cells was significantly increased in PBMs sampled 24 h after the initial injection (P < 0.05). At the end of the first 2 weeks of the protocol, NK cytotoxic activity of PBMs had fallen below the original baseline levels; the higher IFN dose subsequently given was without effect. However, significant increases in the proportion of @entity4071 + cells were seen following each injection. A positive correlation was also seen between the increased lytic activity of @entity4071 + NK cells and the proportion of @entity3053 + NK cells, but not the proportion of @entity2940 + NK cells. In vitro IFN-treatment of these in vivo-treated PBMs resulted in a further increase in NK activity. Pre-exposure in vivo to @entity2391 ser seems to prime the PBMs to respond to in vitro stimulation by @entity379 , which otherwise had no effect. Phenotypic analysis of PBMs after in vitro exposure to @entity2391 ser showed that the levels of @entity4071 +, @entity3053 + and @entity2940 + cells did not change. All the NK activity responding to @entity2391 ser was found in the @entity4071 + enriched population of PBM, suggesting that it is unlikely that in vivo redistribution of @entity4071 + subsets representative of NK cells has occurred in the peripheral blood.
