Pascale Cossart
Encyclopedia
Pascale Cossart is an award-winning bacteriologist
at the Pasteur Institute of Paris
, and the foremost authority on Listeria monocytogenes, a deadly and common food-borne pathogen
responsible for encephalitis
, meningitis
, bacteremia
, gastroenteritis
, and other diseases.
in 1971. She earned her Ph.D. in biochemistry
at the University of Paris
in 1977 (University Paris Diderot). She completed her postdoctoral fellowship at the Pasteur Institute
. She is currently a Professor and Head of the Unité des Interactions Bactéries Cellules at the Pasteur Institute.In 1998, she received the Richard Lounsberry Prize and the L'Oreal/UNESCO Award for Women in Science.
Listeria is a food-borne bacterial pathogen
responsible for numerous illnesses and a mortality rate of 30%. The bacteria
is one of the best models of intracellular parasitism
because it is particularly hardy, able to survive in a variety of cells, cross multiple host barriers, and spreads through actin-based motility. Cossart's work has shed light on the genetic and biochemical processes that make Listeria so effective and lethal, identifying the bsh
gene; regulatory mechanisms such as an RNA
thermosensor that control expression
of the virulence genes such as bsh; and the ways in which Listeria enters cells and crosses physiological barriers such as the blood-brain barrier
, the intestinal barrier, and the placental barrier
. The discovery by Cossart's lab of the interaction between L. monocytogenes protein, internalin
, and its cell receptor, E-cadherin
, was the first such study that successfully demonstrated the molecular mechanism that permits a bacterial agent to cross the placental barrier.
In 2009 Cossart published what she describes as the first "bacterial operon
map" -- the transcriptional program that regulates Listeria's behavior in different environmental conditions. By comparing the sequences of Listeria drawn from soil and drawn from the human gut, Cossart identified non-coding RNA
s that contribute to Listeria's virulence, identified additional RNA repressor
s, and determined that riboswitch
es can act both downstream and upstream.
As part of her work she has also developed important biological tools, including a transgenic mouse that was the first animal model to overcome bacterial species-specificity. The mouse carried a human version of a host cell membrane receptor that L. monocytogenes used to enter cells.
Bacteriology
Bacteriology is the study of bacteria. This subdivision of microbiology involves the identification, classification, and characterization of bacterial species...
at the Pasteur Institute of Paris
Pasteur Institute
The Pasteur Institute is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who made some of the greatest breakthroughs in modern medicine at the time, including pasteurization and vaccines for anthrax...
, and the foremost authority on Listeria monocytogenes, a deadly and common food-borne pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
responsible for encephalitis
Encephalitis
Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningoencephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue...
, meningitis
Meningitis
Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...
, bacteremia
Bacteremia
Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
, gastroenteritis
Gastroenteritis
Gastroenteritis is marked by severe inflammation of the gastrointestinal tract involving both the stomach and small intestine resulting in acute diarrhea and vomiting. It can be transferred by contact with contaminated food and water...
, and other diseases.
Biography
Cossart earned a B.S. and M.S. from Lille University in 1968, and an M.S. in chemistry from Georgetown UniversityGeorgetown University
Georgetown University is a private, Jesuit, research university whose main campus is in the Georgetown neighborhood of Washington, D.C. Founded in 1789, it is the oldest Catholic university in the United States...
in 1971. She earned her Ph.D. in biochemistry
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
at the University of Paris
University of Paris
The University of Paris was a university located in Paris, France and one of the earliest to be established in Europe. It was founded in the mid 12th century, and officially recognized as a university probably between 1160 and 1250...
in 1977 (University Paris Diderot). She completed her postdoctoral fellowship at the Pasteur Institute
Pasteur Institute
The Pasteur Institute is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who made some of the greatest breakthroughs in modern medicine at the time, including pasteurization and vaccines for anthrax...
. She is currently a Professor and Head of the Unité des Interactions Bactéries Cellules at the Pasteur Institute.In 1998, she received the Richard Lounsberry Prize and the L'Oreal/UNESCO Award for Women in Science.
Works
Cossart's studies of the infectious agent Listeria monocytogenes have helped develop a complete picture of this organism and its approaches, offering hope not just for resolving Listeria infection, but also shedding light on bacterial infections generally.Listeria is a food-borne bacterial pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
responsible for numerous illnesses and a mortality rate of 30%. The bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
is one of the best models of intracellular parasitism
Obligate intracellular parasite
Intracellular parasites are parasitic microorganisms - microparasites that are capable of growing and reproducing inside the cells of a host.-Facultative:...
because it is particularly hardy, able to survive in a variety of cells, cross multiple host barriers, and spreads through actin-based motility. Cossart's work has shed light on the genetic and biochemical processes that make Listeria so effective and lethal, identifying the bsh
BSH
BSH may refer to:* Bacillithiol, a thiol compound found in some Gram-positive bacteria* BeanShell, a Java interpreter* Belarusian Socialist Hramada, a political party...
gene; regulatory mechanisms such as an RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
thermosensor that control expression
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
of the virulence genes such as bsh; and the ways in which Listeria enters cells and crosses physiological barriers such as the blood-brain barrier
Blood-brain barrier
The blood–brain barrier is a separation of circulating blood and the brain extracellular fluid in the central nervous system . It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation. Endothelial cells restrict the diffusion...
, the intestinal barrier, and the placental barrier
Placenta
The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply. "True" placentas are a defining characteristic of eutherian or "placental" mammals, but are also found in some snakes and...
. The discovery by Cossart's lab of the interaction between L. monocytogenes protein, internalin
Internalin
Internalins are surface proteins found on Listeria monocytogenes. They exist in two known forms, InlA and InlB. They are used by the bacteria to invade mammalian cells via cadherins transmembrane proteins. The exact role of these proteins and their invasiveness in vivo is not completely understood...
, and its cell receptor, E-cadherin
Cadherin
Cadherins are a class of type-1 transmembrane proteins. They play important roles in cell adhesion, ensuring that cells within tissues are bound together. They are dependent on calcium ions to function, hence their name.The cadherin superfamily includes cadherins, protocadherins, desmogleins, and...
, was the first such study that successfully demonstrated the molecular mechanism that permits a bacterial agent to cross the placental barrier.
In 2009 Cossart published what she describes as the first "bacterial operon
Operon
In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create...
map" -- the transcriptional program that regulates Listeria's behavior in different environmental conditions. By comparing the sequences of Listeria drawn from soil and drawn from the human gut, Cossart identified non-coding RNA
Non-coding RNA
A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...
s that contribute to Listeria's virulence, identified additional RNA repressor
Repressor
In molecular genetics, a repressor is a DNA-binding protein that regulates the expression of one or more genes by binding to the operator and blocking the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes. This blocking of expression is called...
s, and determined that riboswitch
Riboswitch
In molecular biology, a riboswitch is a part of an mRNA molecule that can directly bind a small target molecule, and whose binding of the target affects the gene's activity. Thus, an mRNA that contains a riboswitch is directly involved in regulating its own activity, in response to the...
es can act both downstream and upstream.
As part of her work she has also developed important biological tools, including a transgenic mouse that was the first animal model to overcome bacterial species-specificity. The mouse carried a human version of a host cell membrane receptor that L. monocytogenes used to enter cells.
Significant Publications
- Cellular Microbiology, 2nd Ed. (textbook), edited by Pascale Cossart, Patrice Boquet, and Staffan NormarkStaffan NormarkJan Staffan Normark, born 1945, is a Swedish physician, microbiologist and infectious disease researcher. He grew up in Umeå and was awarded his Ph.D. at Umeå University in 1971. At the end of the 1970s, he was one of the first Swedish scientists to utilise the new genetic engineering tools in...
- Science June 1, 2001
- Nature, May 17, 2009
Awards, Prizes, and Honorary Lectures
- Carlos J. Finlay Prize for MicrobiologyCarlos J. Finlay Prize for MicrobiologyThe Carlos J. Finlay Prize is a biennal scientific prize sponsored by the Government of Cuba and awarded since 1980 by the United Nations Educational, Scientific and Cultural Organization to people or organizations for their outstanding contributions to microbiology and its applications...
(1995) - Richard Lounsbery Award (1998)
- Helena Rubenstein / UNESCO Award for Women in Science LeadershipL'Oréal-UNESCO Awards for Women in ScienceThe L'Oréal-UNESCO Awards for Women in Science aims to improve the position of women in science by recognizing outstanding women researchers who have contributed to scientific progress...
(1998) - Officier de la Légion d'Honneur and Officier de l'Ordre du Merite, French Legion of Honor
- Louis Pasteur Gold Medal (2000), Swedish Society of Medicine
- Valade Prize (2003), Fondation de France
- Margaret PittmanMargaret PittmanDr. Margaret Pittman was a bacteriologist at the Laboratory of Biological Product, Division of Biologics Standards at the U.S. National Institutes of Health whose work on pertussis led to the development of an improved vaccination against whooping cough...
Lecture, National Institutes of HealthNational Institutes of HealthThe National Institutes of Health are an agency of the United States Department of Health and Human Services and are the primary agency of the United States government responsible for biomedical and health-related research. Its science and engineering counterpart is the National Science Foundation...
, 2003 - President, Conseil Scientifique of the Pasteur InstitutePasteur InstituteThe Pasteur Institute is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who made some of the greatest breakthroughs in modern medicine at the time, including pasteurization and vaccines for anthrax...
- Corresponding member, French Academy of SciencesFrench Academy of SciencesThe French Academy of Sciences is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research...
- Member, French Conseil National de la Science
- Member, American Academy of Microbiology
- Member, German Academy of Sciences Leopoldina
- Robert Koch PrizeRobert Koch PrizeThe Robert Koch Medal and Award are two prizes awarded annually for excellence in the biomedical sciences. These awards grew out of early attempts by Robert Koch to generate funding to support his research into the cause and cure for tuberculosis...
, 2007