#trypanosomes

Shrugging Off Insults

Trypanasome parasites – single cell organisms causing sleeping sickness and Chagas disease – shirk attacking antibodies from their host's immune system by rapidly recycling their surface membrane. Here the process is elucidated by high-res techniques including electron and fluorescence microscopy

Read the published article here

Video from work by Fabian Link and colleagues

Department of Cell & Developmental Biology, Biocentre, University of Würzburg, Würzburg, Germany

Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in eLife, April 2024

Pinpointing Parasites

A panel of bioluminescent /fluorescent T. cruzi strains spanning the diversity of the Chagas disease-causing parasite (highlighted here in green among pink neurons) to aid areas of Chagas disease research such as drug development screening

Read the published research article here

Image from work by Francisco Olmo and colleagues

Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Neglected Tropical Diseases, May 2024

Tripping Up Chagas

Chagas disease is a global health threat and neglected tropical disease. It’s a tropical parasite spread mostly by insects, and the molecular mechanisms by which the parasite infects human cells are poorly understood. Researchers probing this damaging infection examined thrombospondin-1 (TSP1), a protein in our cells that mediates cell-to-cell interactions and plays a role in many essential functions. They found that cells lacking this key protein (right, compared to normal cells, left) resisted infection by the parasite Trypanosoma cruzi (green). The team revealed that the parasite activates the β-catenin signalling pathway, a molecular sequence of events crucial in species across the animal kingdom for everything from cell growth to movement. Their results suggest that during early infection, TSP1 enables some of this activity, and that overall the β-catenin pathway is a potential target for treatments or prevention tactics.

Written by Anthony Lewis

Image adapted from work by Ashutosh Arun and colleagues

Department of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, TN, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Neglected Tropical Diseases, January 2022

Travelling by Taxis

Moving in spiralling colonies, young trypanosomes like these can cause fatal sleeping sickness – each wavy tendril is a separate parasite. They develop on a gruesome journey – hiding in mouthfuls of blood sucked into a fly’s gut, they spread through their new airborne home. Later they make a dash for the fly’s salivary glands ready to jump to a new – potentially human – host. Here researchers investigate early procyclic [a life stage] trypanosomes (highlighted in red and green), finding they travel through the fly by reacting to chemical signals produced by their neighbours. Mimicking this natural chemotaxis, these trypanosomes reach out towards unseen alkaline blobs placed on either side of the colony (middle column) but shy away from acid blobs (right). Researchers gain clues to how the parasite’s metabolism guides these acidic cues, and how they might block these vital steps in the spread of disease.

Written by John Ankers

Image from work by Sebastian Shaw and colleagues

Institute of Cell Biology, University of Bern, Bern, Switzerland

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Nature Communications, February 2022

Between the Gaps

To keep a pesky animal out of your garden, you just need to make sure the gaps between your fence posts are narrower than the animal. In our bodies, cells similarly create barriers to keep out unwanted invaders, but some pests are particularly crafty. Trypanosoma brucei is a parasite that causes African Sleeping Sickness, and penetrates deep into our tissues. New research has found how it sneaks in so easily. It can deform its body and squeeze through gaps smaller than its diameter. Its movement and shape is driven by a flagellum – a long propellor-like tail – and researchers engineered parasites with modified flagella to see how they work (bottom two video strips, compared to normal parasites, top). Without their natural flagella they struggled to make progress through small gaps. Clearly flagella are crucial to the parasite’s penetrative power, so trimming the tail might be a way of slowing it down.

Written by Anthony Lewis

Image/video from work by Sun and colleagues

Mechanobiology Institute, National University of Singapore, Singapore

Video originally published under a Creative Commons (CC BY-NC-ND 4.0) attribution

Published in PNAS, June 2018

Parasite Pathways

They’ve got some serious moves Trypanosoma brucei. These parasites are the culprits behind sleeping sickness, a disease native to Africa that if left untreated is fatal. The parasites infect tsetse flies, which go on to bite humans and so the infection is passed on. While in the tsetse fly the parasite develops and matures as it navigates its way through the different organs of the fly. Now using high resolution microscopy researchers reveal a more detailed picture of where and how the parasites (yellow) journey through the fly organs (grey). They discovered that the parasites underwent a range of different movements to successfully traverse through the fly, from moving solo and swimming alongside perceived boundaries to moving about in synchronised swarms. More digging using these high resolution tools may provide further clues to how the parasite develops and survives, with the ultimate goal of learning how to better combat it.

Written by Lux Fatimathas

Image adapted from work by Sarah Schuster and colleagues

University of Würzburg, Würzburg, Germany

Image originally published under a Creative Commons Licence (BY 4.0)

Published in eLife, August 2017

The Scientific Research Notes of S. Sunkavally (years:2002-2011).