Navigation Links
Chlamydia parasite lives off our fat

Invasive bacterial pathogens, the Chlamydiae know us very, very well. The Chlamydiae learned to parasitize eukaryotic cells half a billion years ago by reprogramming cellular functions from within. In humans today, chlamydial infections are responsible for a range of ailments from sexually transmitted infections to atypical pneumonias to chronic severe disorders such as pelvic inflammatory disease and atherosclerosis. The Centers for Disease Control says that Chlamydia trachomatis is the most common sexually-transmitted infection in the US, with three million new cases a year.

Chlamydia gets around because it knows its hosts so well. It's an "obligate intracellular parasite" which means that it relies on its eukaryotic host for everything from reproduction to synthesizing ATP, all while living inside a membrane-bounded vacuole that provides a protected, fertile environment for the bacteria to grow and multiply. Because lipid acquisition from the host is necessary for chlamydial replication, these pathogens are essentially lipid parasites. So, to add insult to injury, Chlamydia apparently lives on our fat.

Lipid droplets are fat-rich structures found in all eukaryotic cells. In humans, lipid droplets are abundant in adipocytes, our professional fat storage cells, where they have traditionally been regarded as passive storage depots of excess fat. However, recent studies have reassessed their role. Lipid droplets are now known to be motile, dynamic and enriched for proteins known to regulate lipid synthesis, membrane traffic and cell signaling. Now in new research presented Sunday at the 45th Annual Meeting of the American Society for Cell Biology in San Francisco, Yadunanda Kumar and Raphael Valdivia of Duke University Medical Center report that Chlamydia loves our lipid droplets.

The discovery of an interaction between lipid droplets and Chlamydia was made as Kumar and Valdivia performed the genetic equivalent of an end-run. Chlamydia is not amenable to direct genetic manipulation so the researchers moved the pathogen's genes elsewhere, inserting them into the eukaryotic cells of baker's yeast. The resulting chlamydial proteins were screened for those that targeted to yeast intracellular organelles. They identified four proteins that were specifically recruited to lipid droplets.

The researchers found that Chlamydia not only directs lipid droplets to its protective vacuole but also causes the proliferation of new lipid droplets on the host. The co-option of lipid droplets appears to be essential for Chlamydia pathogenesis. When the researchers used drugs to inhibit lipid droplet formation in the host, they sharply impaired bacterial growth.

That finding immediately presents a new target for anti-Chlamydia drugs but it also suggests an entirely novel pathogenic mechanism. "We propose that Chlamydia use lipid droplets in a previously unknown pathway for lipid acquisition," says Kumar. "Alternatively, it is possible that the recruitment of lipid droplets constitutes an example of 'organelle mimicry' where Chlamydia escapes recognition by the host by cloaking itself in these fat-rich structures."

Understanding host lipid transport by Chlamydiae may have further implication for chronic infections, the researchers say. For example, lipid-rich macrophages ("foam cells") are a symptom in chlamydial pneumonia. Because foam cells are a key element in development of atherosclerosis, lipid droplet co-option also suggests a possible explanation for the association between chlamydial infections and heart disease.


'"/>

Source:American Society for Cell Biology


Related biology news :

1. Chlamydia vaccine a step closer to reality
2. Scientists reveal molecular secrets of the malaria parasite
3. Protein offers way to stop microscopic parasites in their tracks
4. A human parasite with a streamlined mitochondrion
5. Invasive parasite destroying fish species
6. Measuring hidden parasites in falciparum malaria
7. Three deadly parasite genomes sequenced
8. Researchers at UGA provide first look at protein expression in Chagas disease-causing parasites
9. Researchers discover how malaria parasite disperses from red blood cells
10. US/African project deciphers deadly parasite genome
11. Gene that helps mosquitoes fight off malaria parasite identified
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/14/2016)... , March 14, 2016 NXTD ... growing mobile commerce market, announces the airing of a new ... starting the week of March 21 st .  The commercials ... including its popular Squawk on the Street show. --> ... on the growing mobile commerce market, announces the airing of ...
(Date:3/11/2016)... March 11, 2016 --> ... research report "Image Recognition Market by Technology (Pattern Recognition), ... Advertising), by Deployment Type (On-Premises and Cloud), by Industry ... published by MarketsandMarkets, the global market is expected to ... 29.98 Billion by 2020, at a CAGR of 19.1%. ...
(Date:3/9/2016)... YORK , March 9, 2016 This ... and future states of the RNA Sequencing (RNA Seq) ... segments such as instruments, tools and reagents, data analysis, ... Analyze various segments of the RNA-Sequencing market such as ... services Identify the main factors affecting each segment and ...
Breaking Biology News(10 mins):
(Date:5/6/2016)... Recent studies show that patients no longer ... when treating certain types of pain. With the past ... go right to the source instead of masking the ... provides physician training about the benefits of regenerative adult ... physicians across the United States ...
(Date:5/5/2016)... ... 05, 2016 , ... American Process, Inc. (API) announced that ... Nos. 9,322,133 and 9,322,134, to API and its affiliated companies for BioPlus® nanocellulose ... nanocellulose compositions. In addition to these patents and U.S. Patent No. 9,187,865 ...
(Date:5/4/2016)... Diego, CA (PRWEB) , ... May 04, 2016 ... ... Day? Well, look no further than LaJollaCooks4u, San Diego’s premiere hands-on cooking experience. ... you need to give mom an experience she won’t forget. , Guests that ...
(Date:5/4/2016)... , May 4, 2016 According ... Research "Metabolomics Market - Global Industry Analysis, Size, Share, ... market is anticipated to expand at a CAGR of ... million by 2024. Metabolomics is the extensive ... cells, biofluids, tissues or organisms. Together, these small molecules ...
Breaking Biology Technology: