Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Drug Targets May Fight Tuberculosis and Other Bacterial Infections in Novel Way

03.01.2008
Research Into "Virulence Factors" Expands War Against Infectious Disease Beyond Antibiotics, Weill Cornell Researchers Say

Over the course of the 20th Century, doctors waged war against infectious bacterial illness with the best new weapon they had: antibiotics.

But the emergence of dangerous, multi-drug resistant strains of tuberculosis and other killer infections means that in the 21st century antibiotics are losing ground against bacterial disease.

Now, researchers from Weill Cornell Medical College in New York City say exciting new molecular targets—so-called "virulence factors" that bacteria use to thrive once they are in the host—present an alternative, potent means of stopping TB, leprosy and other bacterial illness.

"We have developed the first inhibitor of a key small molecule from Mycobacterium tuberculosis and Mycobacterium leprae (which causes leprosy) utilized to subvert human host's defenses and damage and invade human host's cells during infection," explains study senior author Dr. Luis Quadri, Associate Professor of Microbiology and Immunology at Weill Cornell.

"With this work, we now have proof of principle for the inhibition of this virulence factor in bacteria cultured in the lab. Our next step is to explore whether this inhibitor can stop these pathogens from multiplying in a mouse host, curtailing infection," Dr. Quadri says.

The findings—published online today in Chemistry and Biology and appearing in the journal's Jan. 26 print edition—highlight what Dr. Quadri has called a "paradigm shift" in infectious disease research.

"We are moving beyond antimicrobials such as antibiotics, which kill the bacterium directly, to anti-infectives, that may have no effect against the pathogen in the test tube but which do compromise its ability to infect and spread in the host," he explains. "We believe that the expansion of the drug armamentarium to include such anti-infective drugs could help the fight against multi-drug resistant infection that has become such a challenge today."

According to World Health Organization data, TB remains one of the world's top-ten leading causes of death, killing nearly two million people each year. Multi-drug resistant strains of M. tuberculosis—as well as even more dangerous, extensive-drug-resistant (XDR) strains of the bug—are emerging each year.

"Obviously, we are going to require more than the traditional antimicrobial approach to turn this situation around," Dr. Quadri says.

In this study, Dr. Quadri, along with co-lead researchers Drs. Julian Ferraras and Karen Stirrett, focused on particular small-molecule virulence factors called phenolic glycolipids (PGLs).

Various strains of M. tuberculosis use PGLs to weaken our body defenses whereas M. leprae uses PGLs to damage and invade our nerve cells during infection.

"Therefore, we hypothesize that drugs blocking PGL synthesis would reduce the adaptive fitness of PGL-producing M. tuberculosis strains in the human host by eliminating PGL-dependent immunomodulatory effects. These drugs may also diminish the ability of M. leprae to invade nerve cells and produce nerve function impairment," Dr. Quadri explains.

In complex work in the laboratory, the researchers investigated and then elucidated a crucial, early step in PGL biosynthesis. They also pinpointed a key enzyme, called FadD22, that is essential to that stage of the process.

"Based on that, we collaborated with Dr. Derek Tan's lab at Memorial Sloan-Kettering Cancer Center to synthesize a molecule that targets FadD22 and successfully inhibits that early step in PGL production," Dr. Quadri said.

Follow-up work using both enzyme assays and M. tuberculosis assays confirmed that the new inhibitor does block the production of PGLs. Although it was technically not possible to test the inhibitor in M. leprae, that pathogen is very closely related to M. tuberculosis, so the researchers believe their agent would inhibit production of PGLs there, as well.

Work is already underway to come up with other, even more potent PGL biosynthesis inhibitors, Dr. Quadri says, with an eye to testing the best candidates in an animal model.

"We are not saying that anti-infectives will ever replace antibiotics, but with pathogens as deadly as M. tuberculosis or as debilitating as M. leprae, you'd ideally like to have as many pharmaceutical weapons in your armamentarium as you can, to use either alone or in combination," Dr. Quadri says.

The new discoveries are highly encouraging, he adds.

"I believe that drugs targeting virulence factors are just one component of the paradigm shift in the antimicrobial drug discovery for the 21st century—one that will offer patients more options in the fight against truly global killers," he says.

This research was funded by the U.S. National Institutes of Health, the Stavros S. Niarchos Foundation, NYSTAR Watson Investigator Program, William H. Goodwin and Alice Goodwin, the Commonwealth Foundation for Cancer Research and MSKCC Experimental Therapeutics Center.

Co-researchers include Xuequan Lu of Memorial Sloan-Kettering Cancer Center, New York City; Jae-Sang Ryu, now at Ewha Woman's University, Seoul, S. Korea; and Clifford E. Soll, Hunter College, New York City.

Weill Cornell Medical College
Weill Cornell Medical College—Cornell University's Medical School located in New York City—is committed to excellence in research, teaching, patient care and the advancement of the art and science of medicine, locally, nationally and globally. Weill Cornell, which is a principal academic affiliate of NewYork-Presbyterian Hospital, offers an innovative curriculum that integrates the teaching of basic and clinical sciences, problem-based learning, office-based preceptorships, and primary care and doctoring courses. Physicians and scientists of Weill Cornell Medical College are engaged in cutting-edge research in such areas as stem cells, genetics and gene therapy, geriatrics, neuroscience, structural biology, cardiovascular medicine, infectious disease, obesity, cancer, psychiatry and public health—and continue to delve ever deeper into the molecular basis of disease in an effort to unlock the mysteries behind the human body and the malfunctions that result in serious medical disorders. The Medical College—in its commitment to global health and education—has a strong presence in such places as Qatar, Tanzania, Haiti, Brazil, Austria and Turkey. With the historic Weill Cornell Medical College in Qatar, the Medical School is the first in the U.S. to offer its M.D. degree overseas. Weill Cornell is the birthplace of many medical advances—from the development of the Pap test for cervical cancer to the synthesis of penicillin, the first successful embryo-biopsy pregnancy and birth in the U.S., the first clinical trial for gene therapy for Parkinson's disease, the first indication of bone marrow's critical role in tumor growth, and, most recently, the world's first successful use of deep brain stimulation to treat a minimally-conscious brain-injured patient. For more information, visit www.med.cornell.edu.

Andrew Klein | EurekAlert!
Further information:
http://www.med.cornell.edu

Further reports about: PGL Pathogen Quadri Tuberculosis Weill anti-infective leprae strains virulence

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>