A conserved trypanosomatid differentiation regulator controls substrate attachment and morphological development in Trypanosoma congolense

Silvester, Eleanor; Szoor, Balazs; Ivens, Alasdair; Awuah-Mensah, Georgina; Gadelha, Catarina; Wickstead, Bill; Matthews, Keith R.

Abstract

Trypanosomatid parasites undergo developmental regulation to adapt to the different environments encountered during their life cycle. In Trypanosoma brucei, a genome wide selectional screen previously identified a regulator of the protein family ESAG9, which is highly expressed in stumpy forms, a morphologically distinct bloodstream stage adapted for tsetse transmission. This regulator, TbREG9.1, has an orthologue in Trypanosoma congolense, despite the absence of a stumpy morphotype in that parasite species, which is an important cause of livestock trypanosomosis. RNAi mediated gene silencing of TcREG9.1 in Trypanosoma congolense caused a loss of attachment of the parasites to a surface substrate in vitro, a key feature of the biology of these parasites that is distinct from T. brucei. This detachment was phenocopied by treatment of the parasites with a phosphodiesterase inhibitor, which also promotes detachment in the insect trypanosomatid Crithidia fasciculata. RNAseq analysis revealed that TcREG9.1 silencing caused the upregulation of mRNAs for several classes of surface molecules, including transferrin receptor-like molecules, immunoreactive proteins in experimental bovine infections, and molecules related to those associated with stumpy development in T. brucei. Depletion of TcREG9.1 in vivo also generated an enhanced level of parasites in the blood circulation consistent with reduced parasite attachment to the microvasculature. The morphological progression to insect forms of the parasite was also perturbed. We propose a model whereby TcREG9.1 acts as a regulator of attachment and development, with detached parasites being adapted for transmission.

Citation

Silvester, E., Szoor, B., Ivens, A., Awuah-Mensah, G., Gadelha, C., Wickstead, B., & Matthews, K. R. (2024). A conserved trypanosomatid differentiation regulator controls substrate attachment and morphological development in Trypanosoma congolense. PLoS Pathogens, 20(2), Article e1011889. https://doi.org/10.1371/journal.ppat.1011889

• Journal Article Type: Article
• Acceptance Date: Feb 8, 2024
• Online Publication Date: Feb 26, 2024
• Publication Date: Feb 26, 2024
• Deposit Date: Apr 24, 2024
• Publicly Available Date: Apr 25, 2024
• Journal: PLoS pathogens
• Print ISSN: 1553-7366
• Electronic ISSN: 1553-7374
• Publisher: Public Library of Science
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Issue: 2
• Article Number: e1011889
• DOI: https://doi.org/10.1371/journal.ppat.1011889
• Public URL: https://nottingham-repository.worktribe.com/output/32449898
• Publisher URL: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1011889