Impact of Laboratory-Adapted Intracellular Trypanosoma cruzi Strains on the Activity Profiles of Compounds with Anti-T. cruzi Activity

Abstract

Chagas disease is caused by infection with the protozoan parasite, Trypanosoma cruzi. The disease causes ~12,000 deaths annually and is one of the world’s 20 neglected tropical diseases, as defined by the World Health Organisation. The drug discovery pipeline for Chagas disease currently has few new clinical candidates, with high attrition rates an ongoing issue. To determine if the Trypanosoma cruzi strain utilised to assess in vitro compound activity impacts activity, a comparison of laboratory-adapted T. cruzi strains from differing geographical locations was undertaken for a selection of compounds with anti-T. cruzi activity. To minimise the possible effect of differences in experimental methodology, the same host cell and multiplicity of infection were utilised. To determine whether the compound exposure time influenced results, activity was determined following exposure for 48 and 72 h of incubation. To ascertain whether replication rates affected outcomes, comparative rates of replication of the T. cruzi strains were investigated, using the nucleoside analogue, 5-ethynyl-2′-deoxyuridine. Minimal differences in the in vitro activity of compounds between strains were observed following 48 h incubation, whereas significant differences were observed following 72 h incubation, in particular for the cytochrome P450 inhibitors tested and the cell cycle inhibitor, camptothecin. Thus, the use of panels of laboratory adapted strains in vitro may be dependent on the speed of action that is prioritised. For the identification of fast-acting compounds, an initial shorter duration assay using a single strain may be used. A longer incubation to identify compound activity may alternatively require profiling of compounds against multiple T. cruzi strains.

Adipocyte-released adipomes in Chagas cardiomyopathy: Impact on cardiac metabolic and immune regulation

“…It is likely that after 96 h post-infection, T. cruzi -infected cultured adipocytes undergo necrotic cell death due to the egression of trypomastigotes after intracellular replication. 79 Adipocyte apoptosis may be a crucial phenomenon in Chagas infection during the asymptomatic stage. We have previously demonstrated that parasites persist in AT during the indeterminate and chronic stages of infection.…”

State-of-the-Art in the Drug Discovery Pathway for Chagas Disease: A Framework for Drug Development and Target Validation

“… 61 , 62 This seems to be particularly important if potentially slow-acting compounds are being evaluated, as inter-strain differences in susceptibility appear to be more evident following 72 hr of compound exposure. 63 …”

“…61,62 This seems to be particularly important if potentially slowacting compounds are being evaluated, as inter-strain differences in susceptibility appear to be more evident following 72 hr of compound exposure. 63 Similarly, the de-prioritization of drugs that act on the parasite 14-α-demethylase (TcCYP51), an enzyme involved in the synthesis of sterols for the parasite membrane, 56 is also becoming increasingly common. The latter is justified on the failure of azoles posaconazole, ravuconazole, and fosravuconazole in clinical trials.…”

Whole-genome assembly of a hybrid Trypanosoma cruzi strain assembled with Nanopore sequencing alone

“…Moreover, even parasite strains adapted to laboratory culture show phenotypic differences in drug susceptibility, in vitro growth capacity, and experimental infectivity in mice ( Brener and Chiari 1965 ; Bice and Zeledon 1970 ; Rodriguez et al . 2014 ; Sykes et al . 2023 ).…”