Article Figures & Data
Figures
- FIG. 1.
Desialylation of human platelets reduces binding by S. mitis. Binding of SF100 (□) to untreated platelets (lane 1), platelets pretreated with sialidase A (lane 2), platelets treated with N- and O-glycanase (lane 3), and platelets treated with N- and O-glycanase and sialidase A (lane 4). Binding of PS344 (▪) to untreated platelets (lane 5), platelets pretreated with sialidase A (lane 6), platelets treated with N- and O-glycanase (lane 7), and platelets treated with N- and O-glycanase and sialidase A (lane 8). Values are expressed as a percentage of wild-type binding to untreated platelets (mean ± SD).
- FIG. 2.
Cleavage of α2-8-linked sialic acid from platelet surfaces results in a reduction of S. mitis binding. Binding of SF100 (□) to untreated human platelets (lane 1) or platelets pretreated with sialidase A (lane 2), sialidase V (lane 3), or sialidase C (lane 4). Binding of PS344 (▪) to platelets (lane 5) or platelets pretreated with sialidase A (lane 6), sialidase V (lane 7), or sialidase C (lane 8). Values presented are expressed as a percentage of wild-type binding to untreated platelets (mean ± SD). Data represent three experiments performed in triplicate on different occasions from a different donor each time. Note that these donors are different from those shown in Fig. 1.
- FIG. 3.
Antibodies to ganglioside GD3 block S. mitis binding to platelets. (A) Binding of SF100 (□) to untreated platelets (lane 1), platelets pretreated with a murine MAb to ganglioside GD3 (lane 2), or a murine MAb to platelet glycoprotein GPIb (lane 3) and binding of PS344 (▪) to untreated platelets (lane 4) platelets pretreated with a murine MAb to ganglioside GD3 (lane 5) or a murine MAb to platelet glycoprotein GPIb (lane 6). (B) Concentration-dependent inhibition of S. mitis (□) and PS344 (▪) binding to platelets by a murine MAb to GD3. Values presented are expressed as a percentage of wild-type binding to untreated platelets (mean ± SD).
- FIG. 4.
Effect of gangliosides on platelet binding by S. mitis. (A) Strains SF100 (□) and PS344 (▒) were incubated with buffer or gangliosides and then tested for binding to platelets. Gangliosides tested were as follows: asialo GM1, GM1, GM3, GD3, GD1a, GD1b, GT1b, and GQ1b. (B) Strains SF100 (□) and PS344 (▪) were incubated with 10-fold dilutions of ganglioside GD3 and then tested for binding to platelets. Values are expressed as a percentage of wild-type binding to platelets (mean ± SD).
- FIG. 5.
Binding of S. mitis to immobilized gangliosides. Strains SF100 (□) and PS344 (▒) were assayed for binding to lactosyl ceramide (A), GM3 (B), and GD3 (C). Values are expressed as a percentage of wild-type binding to ganglioside (mean ± SD).
- FIG. 6.
Direct binding of PblA and PblB proteins to GD3. Clarified culture supernatants of SF100 were passed over GD3 Sepharose (A) or asialo GM1 Sepharose (B) in order to assess the direct binding of PblA and PblB. Lane 1, supernatant; lane 2, flowthrough; lane 3, first column wash; lane 4, final column wash; lane 5, eluate. Protein samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes and probed with antibodies to PblA (αPblA) or PblB (αPblB).
Tables
- TABLE 1.
Gangliosides and glycosphingolipids used in this study
Structure Name Galβ1-4Glcβ1-ceramide Lactosyl ceramide Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-ceramide Asialo GM1 Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-ceramide GM1 Neu5Acα2-3Galβ1-4Glcβ1-ceramide GM3 Neu5Acα2-3 Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-ceramide GD1a Galβ1-3GalNAcβ1-4(Neu5Acα2-8)(Neu5Acα2-3)Galβ1-4Glcβ1-ceramide GD1b Neu5Acα2-8Neu5Acα2-3Galβ1-4Glcβ1-ceramide GD3 Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3)Galβ1-4Glcβ1-ceramide GT1b Neu5Acα2-8Neu5Acα2-3Galβ1-3GalNAcβ1-4 (Neu5Acα2-8Neu5Acα2-3)Galβ1-4Glcβ1-ceramide GQ1b
