Prevalence of tri- and tetraantennary glycans of human? 1-acid glycoprotein in release of macrophage inhibitor of interleukin-1 activity

Abstract

Based on the affinity for concanavalin A (Con A), human alpha 1-acid glycoprotein (AGP) can be separated by chromatography on Con A-Sepharose gel into three variants: Con A unreactive AGP, Con A weakly reactive AGP, and Con A strongly reactive AGP. When exposed to native AGP or to its glycan variants, murine peritoneal macrophages released a factor that inhibited the interleukin-1 (IL-1) proliferative activity as measured in terms of the thymocyte comitogenic assay. Con A unreactive AGP, which contains tri- and tetraantennary glycans and no biantennae, proved to be more effective than Con A weakly and Con A strongly reactive variants, which contain one and two diantennary glycans, respectively. The inhibitory effect was not a function of the negative charge related to the sialyl residues and was not mediated by the mannosyl-fucosyl receptor.

Effect of semisynthetic analog of α1-acid glycoprotein on immunomodulatory and antiinflammatory activity of natural glycoproteinglycoprotein on immunomodulatory and antiinflammatory activity of natural glycoprotein

“…Thus, AGP-A consists only of molecules with 3-and 4-antennary chains, while AGP-B and especially AGP-C include also 2-antennary chains [1,3,8]. AGP-A more efficiently suppresses lymphocyte proliferation [9,14] and inhibits IL-2 production by peripheral blood mononuclear leukocytes (PBML) [2]. However, the role of peptide core and carbohydrate chain of AGP in various biological effects of this acute-phase protein remains unclear.…”

“…It suppresses proliferative response in lymphocyte culture induced by anti-CD3 [14] and phytohemagglutinin [2] and in mixed cell cultures [4]. AGP is an important element of the cytokine network: it activates the production of interleukins IL-I[~, IL-6, and tumor necrosis factor-tz (TNF-ct) [1,10], but, on the other hand, it stimulates the release of inhibiting factor ILl by monocytes/macrophages [9]. The immunomodulatory properties of AGP depend on the microheterogeneity of its carbohydrate chains.…”

cDNA Cloning and Expression of Bovine UDP-N-Acetylglucosamine:α1,3-d-Mannoside β1,4-N-Acetylglucosaminyltransferase IV

“…GnT-IV produces tetra-antennary structures in cooperation with GnT-V, which produces the ␤1-6 linkage of GlcNAc to the ␣1-6 Man of the core structure. This tetra-antennary structure is dominant in certain glycoproteins, such as erythropoietin (EPO) and ␣ 1 -acid glycoprotein, and very important for their bioactivity (1,2). For instance, the in vivo biological activity of recombinant EPO has a positive correlation with the ratio of tetra-/biantennary sugar chains.…”

.ALPHA.1-Acid Glycoprotein Suppresses Rat Acute Inflammatory Paw Edema through the Inhibition of Neutrophils Activation and Prostaglandin E2 Generation

“…It is noteworthy that AGP has been reported to inhibit platelet aggregation, 12,13) suppress proliferative response in lymphocyte cultures induced by anti-CD3 14) and phytohemagglutinin, 15) and increase the secretion of an IL-1 inhibitor by murine macropharges, most likely the IL-1 receptor antagonist. 16,17) Sialyl Lewis X (sLe X ) is the ligand for the cell adhesion molecules E-selectin and P-selectin, which are involved in the inflammation-dependent adhesion of neutrophils, monocytes, or T-cells to endothelial cells or platelets. 18) The sLe X form of AGP is induced during inflammation.…”