Recombinant antibody against Trypanosoma cruzi from patients with chronic Chagas heart disease recognizes mammalian nervous system.

• Main Authors: Leticia L. Niborski, Mariana Potenza, Renato G.S. Chirivi, Leandro Simonetti, Micaela S. Ossowski, Vanina Grippo, Maria May, Daniela I. Staquicini, Adriana Parodi-Talice, Carlos Robello, Marcelo A. Comini, Guillermo D. Alonso, Jos M.H. Raats, Karina A. Gómez
• Format: Article
• Language: English
• Published: Elsevier 2021-01-01
• Series: EBioMedicine
• Subjects: Chagas disease; Phage-display; Tubulin; Molecular mimicry; Post-translational modification; Digestive system
• Online Access: http://www.sciencedirect.com/science/article/pii/S235239642030582X

Background: To deeply understand the role of antibodies in the context of Trypanosoma cruzi infection, we decided to characterize A2R1, a parasite antibody selected from single-chain variable fragment (scFv) phage display libraries constructed from B cells of chronic Chagas heart disease patients. Methods: Immunoblot, ELISA, cytometry, immunofluorescence and immunohistochemical assays were used to characterize A2R1 reactivity. To identify the antibody target, we performed an immunoprecipitation and two-dimensional electrophoresis coupled to mass spectrometry and confirmed A2R1 specific interaction by producing the antigen in different expression systems. Based on these data, we carried out a comparative in silico analysis of the protein target´s orthologues, focusing mainly on post-translational modifications. Findings: A2R1 recognizes a parasite protein of ~50 kDa present in all life cycle stages of T. cruzi, as well as in other members of the kinetoplastid family, showing a defined immunofluorescence labeling pattern consistent with the cytoskeleton. A2R1 binds to tubulin, but this interaction relies on its post-translational modifications. Interestingly, this antibody also targets mammalian tubulin only present in brain, staining in and around cell bodies of the human peripheral and central nervous system. Interpretation: Our findings demonstrate for the first time the existence of a human antibody against T. cruzi tubulin capable of cross-reacting with a human neural protein. This work re-emphasizes the role of molecular mimicry between host and parasitic antigens in the development of pathological manifestations of T. cruzi infection.