Development of a mouse model of Chagas disease and validation of an Aptamer-based assay to detect a biomarker of Trypanosoma cruzi infection

Wednesday, October 26, 2011 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center	FDA/CBER	INFECTDIS-1

Authors

• FF de Araujo
• R Nagarkatti
• E Roffe
• AP Marino
• A Debrabant

Abstract

The blood borne protozoan parasite Trypanosoma cruzi (T. cruzi) is the causative agent of Chagas disease. In order to study disease pathogenesis and validate new diagnostic assays, we developed a mice model of Chagas disease. In this model C57BL/6 mice are infected with the Colombian strain of T. cruzi. Infected animals show a peak of parasitemia at 30 days post infection (dpi), followed by a decrease of parasite numbers in blood reaching undetectable levels by microscopy 100dpi. T. cruzi specific antibodies can be detected 14dpi and IgG levels stay elevated up the 120dpi. Nests of parasites are found in sections of heart tissues 30dpi and strong inflammation is observed in the hearts of infected mice 120dpi, which closely mimic the acute and chronic phases of the disease observed in human infection. This model was used to validate a new Enzyme Linked Aptamer (ELA) assay, in which aptamers (short nucleic acid molecules) developed against T. cruzi excreted/secreted antigens (TESA) are used as parasite specific ligands. Our results showed that the ELA assay can detect TESA in serum of infected mice as early as 7dpi as well as during the chronic phase when parasites are undetectable by microscopy

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