High Circulating Levels of Fibronectin and Antibodies against Its RGD Adhesion Site during Mouse Trypanosoma cruzi Infection: Relation to Survival

• Published in: Experimental parasitology Vol. 80; no. 3; pp. 499 - 506
• Main Authors: Truyens, C., Rivera, M.T., Ouaissi, A., Carlier, Y.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01-05-1995; Elsevier
• Subjects: Acute Disease; Amino Acid Sequence; Analysis of Variance; Animals; Antibodies, Helminth - blood; Biological and medical sciences; Blotting, Western; Cell Adhesion; Chagas Disease - blood; Chagas Disease - immunology; Experimental protozoal diseases and models; Fibronectins - blood; Fibronectins - chemistry; Fibronectins - immunology; Immunoglobulins - blood; Infectious diseases; Male; Medical sciences; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Oligopeptides - chemistry; Oligopeptides - immunology; Parasitemia - blood; Parasitemia - immunology; Parasitic diseases; Protozoal diseases; Receptors, Immunologic - chemistry; Receptors, Immunologic - immunology; Trypanosoma cruzi; Protozoa; Animal model; Host parasite relation; Protozoal disease; Rodentia; Chagas disease; Cell cell interaction; Parasitosis; Adhesion; Fibronectin; Trypanosoma cruzi; Infection; Vertebrata; Mammalia; Mouse; Pathogenic; Rhizoflagellata; Parasitemia; Trypanosomiasis; Humoral immunity
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1006/expr.1995.1062

The levels of fibronectin (FN), a multifunctional glycoprotein known to mediate in vitro Trypanosoma cruzi-host cell adhesion, were measured in the plasma of T. cruzi-infected BALB/c mice. The infection induced a long-lasting increase of fibronectin levels during the acute parasitemic phase of the disease. Immunoblotting analysis showed the occurrence of lower-molecular-size FN fragments in the plasma of acutely infected animals, suggesting an infection-related FN degradation. FN levels were found to be significantly lower in dying mice harboring higher parasitemias than in surviving animals. A weak level of natural IgM against the RGD adhesion site of FN was detected before and during the first 3 weeks of infection. The level was significantly higher in surviving mice. From the fourth week postinfection, a significant increase in the levels of anti-RGD antibodies coincided with a decrease of circulating FN. These antibodies were mainly of the IgM, IgG1, and IgG2a isotypes. Taken together, these data suggest that both FN and anti-FN antibodies may contribute to the outcome of T. cruzi infection in mice.