Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING LLC
GLOBETECH PUBLISHING LLC
PURITAN MEDICAL

Bacterial Quorum Sensing Molecule Targets Host Cell Migration Receptor

By BiotechDaily International staff writers
Posted on 19 Nov 2012
Scientists have discovered a new role and important target on human host cells for a signaling molecule known for its role in quorum sensing of the pathogenic bacteria Pseudomonas aeruginosa.

P. aeruginosa uses N-acylhomoserine lactones (AHLs) as signaling molecules in quorum sensing, whereby it coordinates expression and production of biofilm and virulence factors. AHLs can diffuse through bacterial and eukaryotic cell membranes. At low concentrations, white blood cells, for example, can become more flexible and effective, but at high concentrations the opposite occurs, which weakens immune defenses and increases likelihood of progressive infections and inflammations.

A research team at Linköping University (Linköping, Sweden) has now identified a signaling role for an AHL also in host cells by examining effects on human intestinal epithelial Caco-2 cells. The quorum sensing AHL molecule N-3-oxo-dodecanoyl-L-homoserine lactone (3O-C(12)-HSL) produced by P. aeruginosa was found to modulate Caco-2 cell migration in a dose- and time-dependent manner. The team then demonstrated for the first time that 3O-C(12)-HSL interacts and co-localizes with the IQ-motif-containing GTPase-activating protein (IQGAP1) in Caco-2 cells. Moreover, 3O-C(12)-HSL induced changes in the phosphorylation status of Rac1 and Cdc42 and in the localization of IQGAP1. The study, published online October 11, 2012 in the journal PLoS Pathogens, suggests that the IQGAP1 is a novel receptor for P. aeruginosa 3O-C(12)-HSL and is likely the integrator of Rac1 and Cdc42- dependent altered cell migration.

Prof. Elena Vikström, medical microbiologist and senior author of the study, describes IQGAP1 as something of a double agent — “The protein can both listen in on the bacteria’s communication and change the functions in its host cells,” said Prof. Vikström. She adds, “We have proof that physical contact between bacteria and epithelial cells is not always required; the influence can happen at a distance.” The team’s discovery can open the door to new strategies for treatment where antibiotics cannot help. One possibility is designing molecules that bind to the receptor and thereby block the signaling path for the bacteria; a strategy that could work with cystic fibrosis, for example, as the disease involves sticky mucus made of bacterial biofilm and large amounts of white blood cells formed in the airways.

Related Links:
Linköping University


Channels

Genomics/Proteomics

view channel
Image: Nomarski interference contrast photomicrographs of Cryptosporidium in the feces of an HIV-positive human (Photo courtesy of the CDC - [US] Centers for Disease Control and Prevention).

Advanced Genetic Tools Revamp Search for Drugs to Treat Cryptosporidium

Genetically engineered modifications to genome of the diarrhea-causing parasite Cryptosporidium are expected to expedite research towards vaccine and drug development to prevent or cure infection by this pathogen.... Read more

Drug Discovery

view channel
Image: A new micelle delivery system for the protective polyphenols resveratrol and quercetin (mRQ) may have value in cancer chemotherapy (Photo courtesy of Oregon State University).

Micelles Containing Resveratrol and Quercetin Reverse Doxorubicin Cardiotoxicity

Cancer researchers blocked the toxic effects of the cancer drug doxorubicin (DOX) by administering it together with the plant antioxidants resveratrol and quercetin. Although in use for more than 40... Read more

Lab Technologies

view channel
Image: The Leica DM2500 LED Microscope for clinical laboratories and research applications (Photo courtesy of Leica Microsystems).

New LED Microscope Completes Line of Clinical and Research Tools

A popular microscope used for both clinical and research applications is now available with LED illumination. The Leica (Wetzlar, Germany) DM2500 and DM2500 LED microscopes represent a class of tools... Read more

Business

view channel

Teva Buys Allergan Generic Business Unit

Teva Pharmaceutical Industries (Petah Tikva, Israel) has bought the Allergan (Irvine, CA, USA) generic drugs business for USD 40.5 billion in cash and stock, solidifying its position as the world's largest generic drug maker. Under the terms of the agreement, Teva will pay USD 33.75 billion in cash and USD 6.... Read more
 
Copyright © 2000-2015 Globetech Media. All rights reserved.