Synthesis and biological activities in vitro and in vivo of glycosylated human interleukin-1alpha, neoglyco IL-1alpha, coupled with N -acetylneuraminyl-galactose.

In order to study the effect of glycosylation on its biological activities, and to develop IL-1alpha with less deleterious effects, recombinant human IL-1alpha was chemically coupled with N -acetylneuraminic acid (alpha1-6) galactose (Neu5Ac-Gal). Glycosylated IL-1alpha (Neu5Ac-Gal-IL-1alpha) was purified by anion-exchange chromatography and average number of carbohydrate molecules introduced per molecule of IL-1alpha was 2.5. Neu5Ac-Gal-IL-1alpha exhibited reduced activities about 1/15-fold compared to IL-1alpha in all the activities performed in vitro. Binding affinities of Neu5Ac-Gal-IL-1alpha to Type I and Type II IL-1 receptors were decreased to 1/15 and 1/10, respectively. Neu5Ac-Gal-IL-1alpha exhibited reduction in activities in vivo, including induction of serum amyloid A and NOx, and down-regulation of serum glucose. However, Neu5Ac-Gal-IL-1alpha exhibited comparable activity to IL-1alpha in improvement of the recovery of peripheral white blood cells from myelosuppression in 5-fluorouracil-treated mice. In addition, tissue level of Neu5Ac-Gal-IL-1alpha was relatively high compared to IL-1alpha. These results indicate that coupling with Neu5Ac-Gal enabled us to develop neoIL-1alpha with selective activities in vivo.