scholarly journals Migrating endothelial cells are distinctly hyperglycosylated and express specific migration-associated cell surface glycoproteins.

1992 ◽  
Vol 119 (2) ◽  
pp. 483-491 ◽  
Author(s):  
H G Augustin-Voss ◽  
B U Pauli

Migration of endothelial cells is one of the first cellular responses in the cascade of events that leads to re-endothelialization of an injured vessel and neovascularization of growing tissues and tumors. To examine the hypothesis that endothelial cells express a specific migration-associated phenotype, we analyzed the cell surface glycoprotein expression of migrating bovine aortic endothelial cell (BAECs). Light microscopic analysis revealed an upregulation of binding sites for the lectins Concanavalin A (Con A), wheat germ agglutinin (WGA), and peanut agglutinin after neuraminidase treatment (N-PNA) on migrating endothelial cells relative to contact-inhibited cells. These findings were confirmed and quantitated with an enzyme-linked lectin assay (ELLA) of circularly scraped BAEC monolayers. The expression of migration-associated cell surface glycoproteins was also analyzed by SDS-PAGE. The overall expression of cell surface glycoproteins was upregulated on migrating BAECs. Migrating BAECs expressed Con A- and WGA-binding glycoproteins with apparent molecular masses of 25 and 48 kD that were not expressed by contact-inhibited BAEC monolayers and, accordingly, disappeared as circularly scraped monolayers reached confluence. Subconfluent BAEC monolayers expressed the same cell surface glycoconjugate pattern as migrating endothelial cells. FACS analysis of circularly scraped BAEC monolayers showed that the phenotypic changes of cell surface glycoprotein expression after release from growth arrest occurred before the recruitment of the cells into the cell cycle (3 vs. 12 h). Suramin, which inhibits endothelial cell migration, abrogated the expression of the migration-associated phenotype and induced the expression of a prominent 28-kD Con A- and WGA-binding cell surface glycoprotein. These results indicate that endothelial cells express a specific migration-associated phenotype, which is characterized by the upregulation of distinct cellular glycoconjugates and the expression of specific migration-associated cell surface glycoproteins.

1978 ◽  
Vol 147 (5) ◽  
pp. 1418-1434 ◽  
Author(s):  
AK Kimura ◽  
H Wigzell

T lymphocytes at various stages of maturation and differentiation have been isolated by cellular fractionation procedures and characterized by cell surface markers and functional assays, The cell surface glycoproteins of the various T-cell preparations have been selectively radiolabeled by the galactose oxidase-tritiated sodium borohydride technique and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Details are presented on the appearance of a new cell surface glycoprotein (T 145), present on immunocompetent T lymphocytes after activation by either major histocompatibility complex alloantigens or by concanavalin A. The intensity of T 145 expression on T lymphoblasts is shown to be directly correlated in time and extent to the levels of cytotoxicity generated in a variety of T-cell activations. Specific enrichment procedures of purified populations of mixed leukocyte culture blasts have shown Ly 1(+)2(-) blasts to be T 145(-) and Ly 1(-)2(+) blasts to be strongly T 145(+). Similar enrichment procedures on normal peripheral T cells have failed to reveal any significant expression of T 145 on a highly enriched population of Ly 1(-)2(+) T cells, Further studies on the stability of T 145 expression after induction have shown it to be a more permanent-type differentiation structure whose expression is clearly not linked to the blast stage of activation. T 145 would thus appear to represent a membrane glycoprotein whose exclusive expression on T lymphoblasts is further restricted to a defined group of cells endowed with cytolytic activity and bearing the Ly phenotype Ly 1(-)2(+).


1986 ◽  
Vol 16 (10) ◽  
pp. 1195-1202 ◽  
Author(s):  
Sirpa T. Jalkanen ◽  
Robert F. Bargatze ◽  
Lynne R. Herron ◽  
Eugene C. Butcher

An experimental Trypanosoma cruzi 90 kDa cell surface glycoprotein (GP90) vaccine, previously shown to be protective in mice is similarly effective in marmosets ( Callithrix jacchus jacchus ). Protection in the mouse is completely dependent on the adjuvant saponin and immunological studies confirm that GP90 is intrisically poorly im m unogenic. Both specific antibody and cell mediated im munity are potentiated strongly by saponin and the resulting protective im munity is long lasting (six months). It is effective against the naturally infective, insect-metacyclic, form and a range of heterologous T. cruzi strains including a low mouse passage hum an isolate. Sterile immunity (that is, complete elimination of parasites) was not, however, achieved. Evidence is presented that the levels of tissue dam age associated with acute infection, as measured by production of auto anti-tissue immunoglobulins, are significantly reduced in GP90-immunized mice. These and other results are discussed in terms of the desired characteristics for vaccine use of T. cruzi antigens.


1979 ◽  
Vol 181 (2) ◽  
pp. 451-456 ◽  
Author(s):  
T Krusius ◽  
J Finne ◽  
L C Andersson ◽  
C G Gahmberg

Carbohydrate units of cell-surface glycoproteins of mouse B- and T-lymphocytes, labelled in their sialic acid residues by the periodate/NaB3H4 method and in their galactose residues by the galactose oxidase/NaB3H4 method after neuraminidase treatment, have been studied. Glycopeptides were prepared from the labelled cells by Pronase digestion and fractionated by concanavalin A affinity chromatography into two fractions (A and B). Alkali-labile oligosaccharides were isolated after mild NaOH/NaBH4 treatment by gel filtration. The alkali-labile oligosaccharides were further analysed by t.l.c. To study the relative proportion of neutral mannose-rich carbohydrate units (fraction C) in lymphocyte glycoproteins, glycopeptides were also prepared from unlabelled cells and subjected to concanavalin A affinity chromatography after N-[3H]acetylation of their peptide moiety. The major alkali-labile oligosaccharide component of both cell types was identified as galactosyl-(beta 1 leads to 3)-N-acetylgalactosaminitol. T-Lymphocytes were characterized by a high proportion of this oligosaccharide and a lower proportion of alkali-stable fraction A glycopeptides, whereas the opposite was observed for B-lymphocytes. The relative proportions of the concanavalin A-binding fractions B and C were similar in both cell types. The differences observed may correlate with the different surface properties of B- and T-lymphocytes.


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