Featured Research

from universities, journals, and other organizations

How some trypanosomes cause sleeping sickness while others don't

Date:
May 15, 2014
Source:
PLOS
Summary:
Trypanosome parasites transmitted by tsetse flies cause devastating diseases in humans and livestock. Different subspecies infect different hosts: Trypanosoma brucei brucei infects cattle but is non-infectious to humans, whereas T. b. gambiense and T. b. rhodesiense cause sleeping sickness in humans. A new study reveals how humans can fight off some trypanosomes but not others.

Trypanosome parasites transmitted by tsetse flies cause devastating diseases in humans and livestock. Different subspecies infect different hosts: Trypanosoma brucei brucei infects cattle but is non-infectious to humans, whereas T. b. gambiense and T. b. rhodesiense cause sleeping sickness in humans. A study published on May 15th in PLOS Pathogens reveals how humans can fight off some trypanosomes but not others.

Related Articles


Sam Alsford, from the London School of Hygiene and Tropical Medicine, UK, and colleagues, undertook a comprehensive search for genes that make T. b. brucei sensitive to the innate (the first-line, non-specific) defenses of the human immune system. The hope is that understanding the molecular basis of sensitivity would enable the development of strategies to sensitize resistant trypanosome subspecies. And new drugs are badly needed because existing ones have serious side effects.

The researchers systematically inactivated T. b. brucei genes and looked for parasites which could survive exposure to human blood serum (factors in which can kill this subspecies, making it harmless to humans). Three genes thought to sensitize T. b. brucei to human defenses had been previously identified by other methods, and the researchers re-discovered all three -- plus they found a previously unknown fourth gene in this study.

One of the known genes codes for a protein called inhibitor of cysteine peptidase (or ICP), and the researchers further analyzed its role. Using chemical and genetic approaches, they show that ICP sensitizes T. b. brucei to human serum by dampening the activity of a specific cysteine peptidase (a protein that can cut other proteins) called CATL. In the absence of ICP, CATL is fully active and can counteract components of human serum responsible for killing trypanosomes.

Discussing the findings, Alsford commented: "CATL is under consideration as a potential drug target, and our results suggest that its inactivation could indeed support the human defense system in fighting off disease-causing trypanosome strains. However, as CATL might also be involved in the generation or break-down of other factors involved in parasite-host interactions, it will be important to develop an improved understanding of the complex interplay of all of these factors in human-infective trypanosomes."

The researchers also plan work on the new (fourth) gene they discovered. It codes for a protein that appears to be a so-called transmembrane channel. Studying this channel (which is likely to be involved in the uptake of human defense factors by the parasite) should further improve the understanding of the interaction between the parasite and the anti-trypanosomal components of human serum.


Story Source:

The above story is based on materials provided by PLOS. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sam Alsford, Rachel B. Currier, Josι Afonso Guerra-Assunηγo, Taane G. Clark, David Horn. Cathepsin-L Can Resist Lysis by Human Serum in Trypanosoma brucei brucei. PLoS Pathogens, 2014; 10 (5): e1004130 DOI: 10.1371/journal.ppat.1004130

Cite This Page:

PLOS. "How some trypanosomes cause sleeping sickness while others don't." ScienceDaily. ScienceDaily, 15 May 2014. <www.sciencedaily.com/releases/2014/05/140515173503.htm>.
PLOS. (2014, May 15). How some trypanosomes cause sleeping sickness while others don't. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2014/05/140515173503.htm
PLOS. "How some trypanosomes cause sleeping sickness while others don't." ScienceDaily. www.sciencedaily.com/releases/2014/05/140515173503.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) — The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) — An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins