Characterization of a monoclonal antibody directed against a sulphoglycolipid that is evolutionarily conserved and developmentally regulated in rat brain

Abstract

Summary. Monoclonal antibodies (MABs) have been raised against acidic glycolipids extracted from the electric organ of Torpedo marmorata. One of these, designated L9, appears to recognize acidic glycolipids in adult T. marmorata electric organ, electromotor nerves and brain, adult rat sciatic nerve, and in embryonic and neonatal rat brain, starting at embryonic day (ED) 15 and disappearing by the 20th day of post-natal life. The epitope is present in growth cones isolated from 4-day-old rats; its proportion relative to total gangliosides is, however, no higher than that found in whole neonatal brain membranes. Desialidation of the acidic glycolipid fraction modifies neither the immunoreactivity nor the Rv value following thin-layer chromatography (TLC) of the antigen; it is concluded that the antigen is not a ganglioside. The MAB, HNK-I, recognizes the L9 antigen. Both HNK-1 and L9 recognize a sulphoglycolipid of the same Rv in TLC. The function of the L9 antigen is not known but its evolutionary conservation, presence in growth cones and its developmental regulation in the mammalian central nervous system indicate that it plays an important role in nervous system maturation.

Association of the HNK-1 epitope with 5′-nucleotidase from Torpedo marmorata (electric ray) electric organ

“…The total cellular distribution of the HNK-1 epitope in the electric organ reflects that of a variety of glycoproteins (including acetylcholinesterase and 5'-nucleotidase) and glycolipids (Borroni et al, 1989). In spite of this, the pattern of antibody binding revealed by immunocytochemistry corresponds closely to that previously observed for 5'-nucleotidase (Grondal & Zimmermann, 1987;Grondal et al, 1988).…”

Immunochemical Analysis of a Monoclonal Antibody Recognizing a Terminal Glucuronic Acid-Containing Epitope of Insect Acidic Glycolipids

“…Since there is some structural resemblance between the glucuronic acid-containing glycosphingolipids, the arthrosides, of insects, and the sialic acid-containing gangliosides of vertebrates, it is tempting to speculate that glucuronic acid and sialic acid are of similar biological significance in these two groups of acidic glycolipids. And it might be taken in a support of such a hypothesis that glucuronic acidcontaining glycolipids are indeed also present in the mammalian peripheral nervous system, being also detected as developmentally regulated molecules of the embryonic and neonatal brain [41,44,45]. A preliminary immunohistochemical study using MAb CAF-I has demonstrated that glycoconjugates, that are recognized by this antibody, were differentially expressed at different stages of central nervous system development of the dipteran Ç_^v icina and coleopteran Tenebrio molitor [20] .…”

“…This epitope is present on both, vertebrate glycoproteins and glycolipids. Thus, HNK-1 reacted with a surface antigen on human natural killer cells [39], L2 with glycoproteins from embryonal mouse brain [40], and L9 with acidic glycolipids of the electric organ of Torpedo marmorata [41]. In addition, some patients with an autoallergic demyelinating peripheral neuropathy produced a monoclonal IgM Mprotein that also recognized a sulphated glucuronic acid containing epitope [42].…”