DEVELOPMENT OF GLYCOSYLATED HUMAN INTERLEUKIN-1-ALPHA, NEOGLYCO IL-1-ALPHA, COUPLED WITH D-MANNOSE DIMER - SYNTHESIS AND BIOLOGICAL-ACTIVITIES IN-VITRO

Interleukin 1 (IL-1) is a nonglycosylated cytokine with pleiotropic ef fects on various cell types. In order to investigate the effect of car bohydrate introduction on IL-1 activity and to develop IL-1 with less deleterious effects recombinant human IL-1 alpha was chemically couple d with mannose dimers, alpha-D-Man1-6-D-Man[Man(2)(alpha 1,6)] and alp ha-D-Man1-4-D-Man[Man(2)(alpha 1,4)]. About 5 molecules of mannose dim ers were introduced per molecule of IL-1. Anti-IL-1 alpha antibody rea cted only weakly with the glycosylated IL-1s. Conversely, antibody aga inst the mannose dimer reacted with only glycosylated IL-1. The effect of glycosylation on IL-1 activity was evaluated by measuring a variet y of IL-1 activities in vitro, including proliferative effect on T cel ls, antiproliferative effect on melanoma cells, stimulatory effect on IL-6 synthesis by melanoma cells, and stimulatory effect on prostaglan din E(2) synthesis by fibroblast cells. Glycosylated IL-1s exhibited r educed activities, which were 10-fold to more than several hundred-fol d lower than those of the original IL-1 alpha depending upon different aspects of activities addressed. Man(2)(alpha 1,6)-introduced IL-1 ex hibited lower activity than Man(2)(alpha 1,4)-introduced IL-1. The com petitive binding of I-125-IL-1 alpha to mouse T cells with unlabeled I L-1s suggests that the reduced activity of glycosylated IL-1s is due, at least partially, to the decrease of their receptor binding abilitie s.