Tracking a killer: Observing liver invasion by malarial parasites

May 23, 2005

Despite the efforts of governments and the World Health Organization to combine prevention measures and efforts to eradicate malaria-carrying mosquitoes, the disease kills more than a million people each year. Much is known about the microbes that cause the disease, tiny parasites of the genus Plasmodium, which have a complex life cycle involving several distinct phases and habitats. But, many details of the organism's life cycle, including a critical stage in the parasite's life cycle - invasion of the liver - have escaped direct observation until now. In their new study published in the open-access journal PLoS Biology, Ute Frevert et al. used intravital microscopy - which allows direct observation of events in a living animal - to study the discrete steps that facilitate the parasites' entry into the liver.

To make these observations, the authors introduced genetically engineered Plasmodium parasites that express fluorescent tags to rodents through mosquito bites, and then watched for the arrival of the parasites in the livers of the test animals. They observed parasites crawling along the interior of the liver sinusoids (which take the place of capillaries in the liver), sometimes against the direction of blood flow, until they reached their portal of entry - a specialized cell called a Kupffer cell. They then watched as sporozoites traversed Kupffer cells using a special process distinct from ordinary parasite locomotion.

Upon exiting the Kupffer cell on the other side, the sporozoites wreaked havoc in the liver, leaving a path of destruction and dead cells behind them. They moved through several consecutive hepatocytes before finally settling down in one to begin reproducing. The visualization advantages provided by using the fluorescent parasites and intravital microscopy now make it possible to directly observe events in the Plasmodium life cycle that had only been inferred before. Understanding the invasion will help researchers in the battle against this deadly disease organism.
-end-
Citation: Frevert U, Engelmann S, Zougbede S, Stange J, Ng B, et al. (2005) Intravital observation of Plasmodiumberghei sporozoite infection of the liver. PLoS Biol 3(6): e192.

CONTACT: Ute Frevert
New York University
School of Medicine
341 E 25 St, Lab 401
New York, NY USA 10010
+1-212-263-6755
+1-212-263-8116 (fax)
freveu01@popmail.med.nyu.edu

PLEASE MENTION PLoS Biology (www.plosbiology.org) AS THE SOURCE FOR THESE ARTICLES. THANK YOU.

All works published in PLoS Biology are open access. Everything is immediately available without cost to anyone, anywhere--to read, download, redistribute, include in databases, and otherwise use--subject only to the condition that the original authorship is properly attributed. Copyright is retained by the authors. The Public Library of Science uses the Creative Commons Attribution License.

PLOS

Related Parasites Articles from Brightsurf:

When malaria parasites trick liver cells to let themselves in
A new study led by Maria Manuel Mota, group leader at Instituto de Medicina Molecular, now shows that malaria parasites secrete the protein EXP2 that is required for their entry into hepatocytes.

How deadly parasites 'glide' into human cells
A group of scientists led by EMBL Hamburg's Christian Löw provide insights into the molecular structure of proteins involved in the gliding movements through which the parasites causing malaria and toxoplasmosis invade human cells.

How malaria parasites withstand a fever's heat
The parasites that cause 200 million cases of malaria each year can withstand feverish temperatures that make their human hosts miserable.

New studies show how to save parasites and why it's important
An international group of scientists published a paper, Aug. 1, 2020, in a special edition of the journal Biological Conservation that lays out an ambitious global conservation plan for parasites.

More flowers and pollinator diversity could help protect bees from parasites
Having more flowers and maintaining diverse bee communities could help reduce the spread of bee parasites, according to a new study.

How Toxoplasma parasites glide so swiftly (video)
If you're a cat owner, you might have heard of Toxoplasma gondii, a protozoan that sometimes infects humans through contact with contaminated feces in litterboxes.

Parasites and the microbiome
In a study of ethnically diverse people from Cameroon, the presence of a parasite infection was closely linked to the make-up of the gastrointestinal microbiome, according to a research team led by Penn scientists.

Clocking in with malaria parasites
Discovery of a malaria parasite's internal clock could lead to new treatment strategies.

Feeding bluebirds helps fend off parasites
If you feed the birds in your backyard, you may be doing more than just making sure they have a source of food: you may be helping baby birds give parasites the boot.

Scientists discover how malaria parasites import sugar
Researchers at Stockholm University has established how sugar is taken up by the malaria parasite, a discovery with the potential to improve the development of antimalarial drugs.

Read More: Parasites News and Parasites Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.