Effects of N-acyl-2-hydroxymethyl aziridines on in vitro proliferative responses of human lymphocytes stimulated by mitogens

Aziridines have been shown to possess marked immunotropic activity. The aim of this work was to study the in vitro effects of different concentrations of three novel aziridines, 2-hydroxy-methyl-1-(N-phtaloylglycyl) aziridine (aziridine 1), 2-hydroxy-methyl-1-(N-phtaloylalanyl) aziridine (aziridine 2) and 2-hydroxy-methyl-1-(N-phtaloylphenylalanyl) aziridine (aziridine 3), on the proliferative responses of human lymphocytes stimulated by mitogens (concanavalin A (Con A) and lipopolysaccharide (LPS)), and interleukin-2 (IL-2), interleukin-6 (IL-6) secretion. The results showed that aziridines 1 and 3 significantly stimulated the resting and Con A or LPS lymphocyte proliferation at concentrations between 1 micromol/l and 1 mmol/l, in a dose-dependent manner, the action of aziridine 3 being the highest. They also increased IL-2 and IL-6 secretion. However, aziridine 2 had no effect on the resting lymphocyte proliferation in the absence of mitogens, at any concentration used, reduced Con A-stimulated T lymphocyte proliferation and LPS- stimulated B lymphocyte proliferation in a dose dependent manner and diminished IL-2 and IL-6 production. None of the three aziridines affected cell viability. In conclusion, the three aziridines used in this study displayed immunomodulatory properties. Aziridines 1 and 3 are potentially immunostimulant while aziridine 2 is immunosuppressive and could be used to provide nonspecific cell-mediated immune responses.