Identification and isolation of Trypanosoma cruzi trypomastigote collagen-binding proteins: possible role in cell-parasite interaction.
We have shown here that collagen type I bound efficiently to the trypomastigote surface. In addition, monoclonal and polyclonal antibodies against collagen types I and III inhibited the infection of fibroblasts by the parasite. These results suggested the presence of collagen-binding protein(s) on the parasite surface. This protein was identified from trypomastigote surface antigens using affinity chromatography on a Gelatin Ultrogel column (denatured form of collagen). These collagen-binding proteins were revealed as a low-affinity gelatin binding protein (LAG Bp) of 98 kDa, and a high-affinity binding protein (HAG Bp) of 58 and 68 kDa under non-reducing and reducing conditions respectively. In addition, HAG Bp and LAG Bp bound to collagen type I. The 58/68 kDa protein was purified to homogeneity on a wheat germ agglutinin Sepharose column. A polyclonal antibody to this glycoprotein, as well as a monoclonal antibody (McAb) 155D3 produced against the HAG Bp, immunoprecipitated two parasite surface antigens of 160 and 58 kDa under non-reducing conditions which migrated at a position of 80-85 and 68 kDa when reduced. However, only the 80-85 kDa component could be precipitated from [35S] methionine-labelled trypomastigote antigens under reducing conditions. The antibodies to the 58/68 kDa glycoprotein as well as McAb 155D3 diminished the invasion of fibroblasts by parasites. Taken together these results suggest that the same receptor binds fibronectin and/or collagen and that both the 80-85 and 58/68 kDa glycoproteins form part of the same receptor. These trypomastigote surface molecules may interact with the host cell fibronectin and/or collagen during the initial phase of parasite-cell recognition.
Velge
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P
Unité Mixte INSERM U 167 - CNRS 624, Institut Pasteur, Lille, France.
Ouaissi
M A
MA
Cornette
J
J
Afchain
D
D
Capron
A
A
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D002460:Cell Line; D002846:Chromatography, Affinity; D003094:Collagen / Q000276:immunology / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts; D015151:Immunoblotting; D011233:Precipitin Tests; D011956:Receptors, Cell Surface / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D038981:Receptors, Collagen; D014349:Trypanosoma cruzi / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D011956:Receptors, Cell Surface; D038981:Receptors, Collagen; D003094:Collagen