Developmental regulation of ganglioside antigens recognized by the JONES antibody

Abstract

The JONES monoclonal antibody has been immunocytochemically associated with regions of the developing rat brain where cell and axon migrations are occurring (Mendez-Otero et al., 1986, 1988). In the present study the antigens recognized by the JONES antibody were analyzed in a variety of brain regions and at developmental ages selected to correspond to the preceding immunocytochemical observations. In accordance with earlier results from retina, JONES binding could not be detected in SDS gels from developing brain. Binding of the antibody was, however, prominent in chloroform/methanol extracts of the same tissues, and it was completely removed from tissue sections by brief chloroform/methanol form/methanol treatment. Enzymatic analyses of chloroform/methanol extracts indicated that the JONES epitope was sensitive to neuraminidase but insensitive to proteases. Overlay assays on developed high-performance thin-layer chromatographic plates (HPTLC) indicate that in all regions the JONES epitope resides on 2 or 3 ganglioside bands, depending on the age examined. These bands migrate between ganglioside standards GD 1a and GM2 on HPTLC plates and have been designated GJ1, GJ2, and GJ3, with the higher number designating the more rapidly migrating species. Occasionally, additional bands migrating in the range of polysialogangliosides were observed. The pattern of expression of GJ species was studied in forebrain, retina, and cerebellar tissue taken from embryonic day 18 (E18), postnatal day 0 (P0), P7, P14, and adult animals. Both region-specific differences in the relative prominence of each band and stage-specific differences in the total amount of the JONES gangliosides were detected. The stage- specific differences in the amount of JONES antigens are well correlated with the developmental periods of maximal cell migration in each region. While the JONES gangliosides are most prominent in forebrain before birth, in they are most prominent during the first 2 postnatal weeks. In cerebellum, JONES antigen expression is more pronounced during the 2 periods of cell migration in this tissue. In retina, the more rapidly migrating GJ3 band was the most prominent band at all stages examined, and this same band is retained in the adult. In cerebellum and forebrain GJ3 is also the most pronounced band during development. However, in contrast to the retina, the more slowly migrating GJ1 band is retained in adult forebrain and cerebellum. A variety of non-brain tissues have also been examined for the presence of the JONES antigens.

Lysosomal and Cytosolic Sialic Acid 9-O-Acetylesterase Activities Can Be Encoded by One Gene via Differential Usage of a Signal Peptide-encoding Exon at the N Terminus

“…This O-acetylation of Sia is a common modification found in mammalian cell surface sialoglycoconjugates and can also be present on free Sias in the cytosol (15,16). One example of a well characterized O-acetylated sialoglycoconjugate is 9(7)-Oacetylated-G D3 and structurally related disialogangliosides, which show developmentally regulated expression and gradient patterns for its staining with monospecific antibodies in the developing brain (17,18). Specific antibodies showed that the expression of 9-O-acetylated G D3 appears to be independently regulated from that of the parental molecule, G D3 (18), and occurs on the migrating neural cells (19).…”

Functional role of a specific ganglioside in neuronal migration and neurite outgrowth

“…The particular epitope recognized by the Jones mAb depends upon the acetyl group at position 9 of sialic acid and the immunoreactivity is abolished by mild base treatment since this treatment converts 9-O-acetyl GD3 to GD3 that is not recognized by the Jones mAb (13,30,31). This antigen is abundant in the nervous system and in tumor cells derived from the neural crest, and is absent in most of the other tissues examined (29). However, the same epitope was described in the immune system and was designated CD60b (32).…”

“…In our initial studies we have shown that the pattern of staining with this antibody in the developing rat nervous system correlates temporally and spatially with neuronal migration and neurite outgrowth (28,29). The biochemical characterization of the antigen revealed that this mAb recognizes a ganglioside that migrates between GM1 and GM2 ganglioside standards.…”

“…Further characterization using overlay assays on developed high-performance thin-layer chromatography plates indicates that the epitope recognized by the Jones mAb is expressed in several regions of the developing central and peripheral nervous system. In most regions examined the epitope resides in two bands (29). Further analysis has revealed that the most abundant and frequent band is 9-O-acetyl GD3, a modification of GD3 ganglioside in which an acetyl ester is formed at position 9 of the terminal sialic acid residue ( Figure 1B) (13).…”

“…In the developing nervous system, we have shown that the expression pattern of this specific Jones mAb reactive ganglioside correlates with times of cell migration in the retina (Figure 2), superior colliculus, cerebellum, and telencephalon and in regions undergoing neurite extension, such as the developing optic tract, the white matter of the cerebellum, the dorsal roots (Figure 3), the trigeminal system, and olfactory nerve (12,28,29,33,(37)(38)(39). This has led us to suggest that the function of 9-O-acetyl GD3 is to modulate motility either directly or by modifying the efficacy of some other component of the system (39,40).…”