Formation of filopodia in Trypanosoma congolense by crosslinking the variant surface antigen.
Trypanosoma congolense was exposed to various substances binding to the variant surface antigen (VSG). All methods of crosslinking VSG molecules caused the rapid accumulation of ligands along the line of flagellar attachment and their shedding by formation of coat-covered vesicles and filopodia. This phenomenon was observed after treatment of the parasites with concanavalin A (Con A), anti-VSG-IgG plus protein A-gold, attachment of the cells to surfaces coated with poly-L-lysine and Con A and to Formvar films before negative staining. Moreover, trypanosomes aggregated by primary antibodies formed vesicles and filopodia at the points of contact. Those antibodies bound to the remaining cell surface, however, remained distributed uniformly. This indicates that primary antibodies alone do not cause crosslinking of VSG on the surface of T.congolense.
Frevert
U
U
Institute of Veterinary Biochemistry, Free University Berlin, Federal Republic of Germany.
Reinwald
E
E
D000818:Animals; D000913:Antibodies, Protozoan / Q000378:metabolism*; D000953:Antigens, Protozoan / Q000378:metabolism*; D000954:Antigens, Surface / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D014348:Trypanosoma congolense / Q000187:drug effects / Q000276:immunology* / Q000648:ultrastructure
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D003432:Cross-Linking Reagents