ABC | Volume 110, Nº4, April 2018

Original Article Vimentin and Anti Vimentin Antibodies in Chagas’ Disease Marilda Savoia Nascimento, Anna Maria Simonsen Stolf, Heitor Franco de Andrade Junior, Ramendra Pati Pandey, Eufrosina Setsu Umezawa Universidade de São Paulo (USP), São Paulo, SP – Brazil Mailing Address: Marilda Savoia Nascimento • Av. Senador Vergueiro, 608. Postal Code 09750-000, Centro, São Bernardo do Campo, São Paulo, SP – Brazil E-mail: marildasavoia@gmail.com Manuscript received on June 13, 2017; revised manuscript on September 05, 2017; accepted on October 06, 2017 DOI: 10.5935/abc.20180038 Abstract Background: Vimentin is a main structural protein of the cell, a component of intermediate cell filaments and immersed in cytoplasm. Vimentin is mimicked by some bacterial proteins and anti-vimentin antibodies occur in autoimmune cardiac disease, as rheumatic fever. In this work we studied vimentin distribution on LLC-MK2 cells infected with T. cruzi and anti-vimentin antibodies in sera from several clinical pictures of Chagas’ disease or American Trypanosomiasis, in order to elucidate any vimentin involvement in the humoral response of this pathology. Objective: We standardized an indirect immunofluorescence assay (IFI) to determine sub cellular expression in either parasites and host cells, and ELISA to evaluate anti-vimentin antibodies in sera fron chagasic patients. Methods: We analyzed the distribution of vimentin in culture cells using indirect fluorescent assays, using as external controls anti-T. cruzi sera, derived from chronic infected patients for identification of the parasites in the same model. After infection and growth of T.cruzi amastigotes, those cells express larger amounts of vimentin, with heavy staining of cytoplasm outside the parasitophorous vacuole and some particle shadowing patterns, suggesting that vimentin are associated with cell cytoplasm. Anti-vimentin antibodies were present in most American trypanosomiasis samples, but notably, they are much more present in acute (76, 9%) or clinical defined syndromes, especially cardiac disease (87, 9%). Paradoxically, they were relatively infrequent in asymptomatic (25%) infected patients, which had a clearly positive serological reaction to parasite antigens, but had low frequency of anti-vimentin antibodies, similar to controls (2,5%). Conclusion: Our current data revealed that anti-vimentin antibodies induced during T. cruzi infection could be a marker of active disease in the host and its levels could also justify drug therapy in American Trypanosomiasis chronic infection, as a large group of asymptomatic patients would be submitted to treatment with frequent adverse reactions of the available drugs. Anti-vimentin antibodies could be a marker of cardiac muscle cell damage, appearing in American Trypanosomiasis patients during active muscle cell damage. (Arq Bras Cardiol. 2018; 110(4):348-353) Keywords: Chagas Disease; Heart Diseases; Trypanossoma Cruzi; Rheumatic Fever; Vimentin; Antibodies, Monoclonal. Introduction Chagas’ disease or American Trypanosomiasis is a peculiar parasitic infection as Trypanosoma cruzi is a unique intracellular parasite which resulted in cytoplasmic presence of amastigotes forms, a rare cellular event in nature, as cytoplasm is usually free from parasites in almost all intracellular infections 1 . After its reproduction, the parasite had a set of enzymes, as sialidases, that transfers host cell molecules to their surface, allowing cell evasion without disruption 2 . All those processes could alter cell cytoskeleton and its proteins, probably generating in the host cell signals that alters the protein synthesis of structural proteins. Vimentin is a main structural protein of the cell, a component of intermediate cell filaments and immersed in cytoplasm 3 . Vimentin is expressed in normal cardiac muscle and their tumors, and autoantibodies against a vimentin re found in allograft rejection 4 . or cardiac models of allograft rejection 5 .Vimentin is mimicked by some bacterial proteins and anti-vimentin antibodies occur in autoimmune cardiac disease, as rheumatic fever 6 . In this work we studied vimentin distribution on LLC-MK2 cells infected with T.cruzi and anti-vimentin antibodies in sera from several clinical pictures of American Trypanosomiasis, in order to elucidate any vimentin involvement in the humoral response of this pathology. Methods Parasites and serum samples Trypanosoma cruzi epimastigotes were grown from Y strain routinely maintained in our lab on Liver Infusion Tryptose (LIT) culture media supplemented with 10% fetal calf serum. T. cruzi trypomastigotes were obtained from cell culture supernatants of LLC-MK2 cells previously infected. Monoclonal mouse Anti-Vimentin antibody (V6630) and 348