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 Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>