title: Interaction of Trypanosoma evansi with the plasminogen-plasmin system.
abstract: Trypanosoma evansi is a widely-distributed haemoflagellated parasite of veterinary importance that infects a variety of mammals including horses, mules, camels, buffalos, cattle and deer. It is the causal agent of a trypanosomiasis known as Surra which produces epidemics of great economic importance in Africa, Asia and South America. The main pathology includes an enlarged spleen with hypertrophy of lymphoid follicles, congested lungs, neuronal degeneration and meningoencephalitis, where migration of the parasites from the blood to the tissues is essential. Most cells, including pathogenic cells, use diverse strategies for tissue invasion, such as the expression of surface receptors to bind plasminogen or plasmin. In this work, we show that T. evansi is able to bind plasminogen and plasmin on its surface. The analysis of this binding revealed a high affinity dissociation constant (Kd of 0.080±0.009μM) and 1×10(5) plasminogen binding sites per cell. Also a second population of receptors with a Kd of 0.255±0.070μM and 3.2×10(4) plasminogen binding sites per cell was determined. Several proteins with molecular masses between ∼18 and ∼70kDa are responsible for this binding. This parasite-plasminogen interaction may be important in the establishment of the infection in the vertebrate host, where the physiological concentration of available plasminogen is around 2μM.
authors: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela. Electronic address: hectoracosta@ula.ve.
authors: Héctor
authors: H
authors: Acosta
authors: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors: Rocío
authors: R
authors: Rondón-Mercado
authors: Laboratorio de Fisiología Animal. Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors: Luisana
authors: L
authors: Avilán
authors: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors: Juan Luis
authors: JL
authors: Concepción
mesh_terms: D015119:Aminocaproic Acid / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002254:Carbonates / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D005341:Fibrinolysin / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006736:Horses; D007106:Immune Sera / Q000276:immunology; D008861:Microsomes / Q000737:chemistry / Q000187:drug effects; D010958:Plasminogen / Q000276:immunology / Q000378:metabolism*; D015800:Protozoan Proteins / Q000032:analysis; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000378:metabolism; D014345:Trypanosoma / Q000378:metabolism* / Q000472:pathogenicity / Q000502:physiology; D014352:Trypanosomiasis / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D014404:Tubulin / Q000276:immunology; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D002254:Carbonates; D007106:Immune Sera; D015800:Protozoan Proteins; D011956:Receptors, Cell Surface; D014404:Tubulin; C005686:sodium carbonate; D010958:Plasminogen; D005341:Fibrinolysin; D014568:Urokinase-Type Plasminogen Activator; D015119:Aminocaproic Acid
keywords: Mechanism of invasion; Plasmin; Plasminogen; Trypanosoma evansi