title: High circulating levels of fibronectin and antibodies against its RGD adhesion site during mouse Trypanosoma cruzi infection: relation to survival.
abstract: 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.
authors.affiliation: Laboratoire de Parasitologie, Faculté de Médecine, Université Libre de Bruxelles, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Truyens
authors.forename: M T
authors.initials: MT
authors.lastname: Rivera
authors.forename: A
authors.initials: A
authors.lastname: Ouaissi
authors.forename: Y
authors.initials: Y
authors.lastname: Carlier
mesh_terms: D000208:Acute Disease; D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D015153:Blotting, Western; D002448:Cell Adhesion; D014355:Chagas Disease / Q000097:blood* / Q000276:immunology; D005353:Fibronectins / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D007136:Immunoglobulins / Q000097:blood; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000276:immunology*; D018512:Parasitemia / Q000097:blood* / Q000276:immunology; D011971:Receptors, Immunologic / Q000737:chemistry / Q000276:immunology
chemical_list: D000909:Antibodies, Helminth; D005353:Fibronectins; D007136:Immunoglobulins; D009842:Oligopeptides; D011971:Receptors, Immunologic; C047981:arginyl-glycyl-aspartic acid