Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Crack Sparse Genome of Microbe Linked to Autoimmunity

16.09.2011
Research Adds to Growing Knowledge of How Gut Bacteria Influence Health

Scientists have deciphered the genome of a bacterium implicated as a key player in regulating the immune system of mice. The genomic analysis provides the first glimpse of its unusually sparse genetic blueprint and offers hints about how it may activate a powerful immune response that protects mice from infection but also spurs harmful inflammation.

The researchers, led by Dan Littman, the Helen L. and Martin S. Kimmel Professor of Molecular Immunology at NYU School of Medicine and a Howard Hughes Medical Institute Investigator, and Ivaylo Ivanov, PhD, of Columbia University Medical Center, published their findings in the September 15, 2011, issue of Cell Host and Microbe. The study suggests that the gut-dwelling microorganism, named segmented filamentous bacteria (SFB), is genetically distinct from all 1,200 bacterial genomes studied so far, reflecting its relatively unique role in the gut.

Although SFB was first identified more than 40 years ago, it wasn’t until 2009 that Dr. Littman and an international team of collaborators discovered that it can recruit specialized T cells, called Th17 cells, in the small intestine of mice. These potent immune cells, they subsequently found, protected the mice from disease-causing Citrobacter rodentium bacteria, but also made them more susceptible to inflammation and autoimmune arthritis. Those initial results suggested other intestinal bacteria might also regulate immune function.

“What has become clear in the last couple of years is that individual bacteria can specifically influence particular branches of the immune system,” says Dr. Littman. In the new study, his team deciphered SFB’s 1.57 million letters of DNA, almost 2,000 times smaller than our own genome and about one-third the size of its closest relative.

The microbe’s sparse genome lacks many genes needed for its own survival, such as ones for making amino acids and other essential nutrients. As a result, it is dependent on other gut-dwelling bacteria or its host for food, according to the study. The examination of its 1,500 genes, however, suggests it is well adapted to the small intestine, where it clings to the thin lining and may help prevent other microbes from breaching the barrier.

Although the study didn’t uncover any definitive signs of the SFB living within us, Dr. Littman suspects the resourceful bacteria have adapted to certain human populations. Even if it isn’t found in our intestinal tract, scientists could apply what they have learned to obtain insights into the function of similarly acting microorganisms within us.

“Maybe in humans, there is another bacterium that is different from SFB but behaves functionally in the same way,” says Dr. Ivanov, who conducted the latest analysis as a postdoctoral researcher in Dr. Littman’s lab.

Recently, Japanese researchers found intestinal bacteria in humans that can boost development of regulatory immune cells in mice, thereby keeping the inflammatory activity of Th17 cells in check. Dr. Littman and his NYU collaborators may have also uncovered a microbe in the intestinal tract of rheumatoid arthritis patients that alters immune function. These emerging results underscore the need to understand how the microbes living in our bodies may impact our health.

"This research brings us the potential genetic mechanisms that trigger differentiation of Th17 cells which we have long believed to have a strong role in the development of autoimmune diseases, including rheumatoid arthritis (RA), psoriatic arthritis (PsA), and Crohn’s disease," said Steven Abramson, MD, professor, Departments of Medicine and Pathology and director of the Rheumatology Division at NYU Langone Medical Center. "With more than 50 million Americans suffering from at least one autoimmune disease, this research gives scientists and clinicians a greater ability to apply knowledge gained in the laboratory to actual clinical cases, moving it from 'bench-to-beside' to give patients a tremendous advantage and physicians the ability to fine-tune medications and protocols based on patient response."

About NYU Langone Medical Center
NYU Langone Medical Center, a world-class, patient-centered, integrated, academic medical center, is one on the nation’s premier centers for excellence in clinical care, biomedical research and medical education. Located in the heart of Manhattan, NYU Langone is composed of three hospitals – Tisch Hospital, its flagship acute care facility; the Rusk Institute of Rehabilitation Medicine, the world’s first university-affiliated facility devoted entirely to rehabilitation medicine; and the Hospital for Joint Diseases, one of only five hospitals in the nation dedicated to orthopaedics and rheumatology – plus the NYU School of Medicine, which since 1841 has trained thousands of physicians and scientists who have helped to shape the course of medical history. The medical center’s tri-fold mission to serve, teach and discover is achieved 365 days a year through the seamless integration of a culture devoted to excellence in patient care, education and research. For more information, go to www.NYULMC.org.

Christopher Rucas | Newswise Science News
Further information:
http://www.nyumc.org

More articles from Life Sciences:

nachricht Fine organic particles in the atmosphere are more often solid glass beads than liquid oil droplets
21.04.2017 | Max-Planck-Institut für Chemie

nachricht Study overturns seminal research about the developing nervous system
21.04.2017 | University of California - Los Angeles Health Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>