Gamma Interferon‐Induced Specific Binding of Tetanus Toxin on the GG2EE Macrophage Cell Line

Abstract
We have recently demonstrated that tetanus toxin (TT) selectively inhibited gamma interferon-(IFN-.gamma.)-induced, but not basal, lysozyme activity in the GG2EE macrophage cell line. By an indirect immunofluorescence technique, we show that tetanus toxin, as well as the BIIb tetanus toxin-derived fragment, selectively binds to IFN-.gamma.-treated cells but fails to bind to control cells. Moreover, BIIb fragment and TT share the same binding sites, as demonstrated by competition/displacement experiments. These data indicate that IFN-.gamma. pretreatment results in the acquisition of tetanus toxin binding sites on GG2EE cells by a mechanisms(s) yet to be identified.