In a new study from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, scientists have discovered L. major does its damage by not only evading but also by exploiting the body's wound-healing response to sand fly bites, as reported in the August 15 issue of Science.
"This work changes the textbook picture of the lifecycle of the leishmaniasis parasite, identifying the inflammatory cell known as the neutrophil as the predominant cell involved during the initiation of infection," says NIAID Director Anthony S. Fauci, M.D.
Employing advanced microscopy techniques, which allowed real-time imaging of the skin of living mice infected with L. major, NIAID collaborators Nathan C. Peters, Ph.D., and Jackson Egen, Ph.D., found that the neutrophils—white blood cells that ingest and destroy bacteria—play a surprising role in the development of the disease.
Neutrophils were rapidly recruited out of the circulating blood and into the skin of infected mice, where they swarmed around the sand fly bite sites and efficiently engulfed the parasites. But unlike many other infectious organisms that die inside neutrophils, L. major parasites appear to have evolved in a way to evade death, actually surviving for long periods of time inside the neutrophils. Eventually the parasites escape from neutrophils and enter macrophages, another immune cell population in the skin, where they can establish long-term infection.
"Parasites transmitted by sand flies to mice lacking neutrophils have more difficulty establishing an infection and surviving. This demonstrates the importance of neutrophils at the site of an infected sand fly bite and suggests the unexpected path taken by the parasite from sand fly to neutrophil to macrophage is a critical component of this disease," says Dr. Peters.
In addition, says Dr. Egen, the study reveals how neutrophils leave locally inflamed blood vessels and move into tissues; provides new information on the movement of these immune cells within damaged tissue environments and upon contact with pathogens; and provides video images revealing active neutrophil entry into areas of damaged skin.
When fat cells change their colour
28.10.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau
Aquaculture: Clear Water Thanks to Cork
28.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH
Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.
So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
28.10.2016 | Power and Electrical Engineering
28.10.2016 | Physics and Astronomy
28.10.2016 | Life Sciences