New research on signaling pathways in immune cells bolsters evidence of connections between the central nervous system and the immune system. The findings may also advance the scientific foundation for a potential HIV treatment that may block the virus that causes AIDS.
The cell culture study by a research team from The Children’s Hospital of Philadelphia and the University of Pennsylvania appears in the Proceedings of the National Academy of Sciences, published online on May 4.
The team, led by Steven D. Douglas, M.D., chief of the Section of Immunology at The Children’s Hospital of Philadelphia, analyzed neurokinin-1 receptors found on the surfaces of monocytes, immune cells that develop into macrophages. The neurokinin-1 receptors (NK-1R) are docking sites for substance P, a well-known neurotransmitter that plays important roles in both immune function and the nervous system.
In the current study, the Douglas team investigated two forms of NK-1R in a human monocyte/macrophage cell line. One was a full-length receptor, the other a shortened version with fewer amino acids. When the researchers added substance P to cell cultures with the receptors, both responded with an increase in calcium ions, but used distinct signaling pathways.
The truncated NK-IR did not respond directly to substance P, but worked through another signaling molecule, the chemokine RANTES, to increase the calcium flow. The RANTES molecule is important because it binds to another cell receptor, CCR5, which is crucial in allowing common strains of HIV (R5 strains) to infect immune cells.
Significantly, when the investigators added the drug aprepitant, which binds to NK-1R, to their cell cultures, it inhibited signaling from both the full-length and short form of the receptors.
Although the current study was not focused on HIV infection, it directly relates to broader interests of Dr. Douglas’ laboratory. He currently leads a four-year program project grant from the National Institute of Mental Health, entitled, "Neurokinin-1R (Substance P Receptor) Antagonists for HIV Therapy." One project within that grant will conduct a phase 1 (safety) trial of aprepitant in adults with HIV infection. Currently used as an anti-nausea medication, aprepitant, which has the trade name Emend, might also block HIV infection.
Because macrophages are a reservoir for HIV, a strategy that denies the virus entry into those immune cells may be important in combating HIV infection. Dr. Douglas showed in 2001 that another NK-1R antagonist blocked HIV replication within macrophages in cell culture. The hope is that aprepitant may show a similar protective effect in patients.
"We postulate that blocking NK-1R may send signals to turn off the CCR5 receptor for HIV, closing the door to the virus," said Dr. Douglas. "Underlying the signaling mechanisms are the questions, ’how does the immune system talk to the nervous system?’ and ’how does the nervous system talk back?’ Substance P is a link between both systems, and this study increases our understanding of those underlying questions."
John Ascenzi | EurekAlert!
Quasi-sexual gene transfer drives genetic diversity of hot spring bacteria
29.05.2015 | Carnegie Institution
Scientists use unmanned aerial vehicle to study gray whales from above
29.05.2015 | NOAA National Marine Fisheries Service
Many joining and cutting processes are possible only with lasers. New technologies make it possible to manufacture metal components with hollow structures that are significantly lighter and yet just as stable as solid components. In addition, lasers can be used to combine various lightweight construction materials and steels with each other. The Fraunhofer Institute for Laser Technology ILT in Aachen is presenting a range of such solutions at the LASER World of Photonics trade fair from June 22 to 25, 2015 in Munich, Germany, (Hall A3, Stand 121).
Lightweight construction materials are popular: aluminum is used in the bodywork of cars, for example, and aircraft fuselages already consist in large part of...
Using ultrashort laser pulses, scientists in Max Planck Institute of Quantum Optics have demonstrated the emission of extreme ultraviolet radiation from thin dielectric films and have investigated the underlying mechanisms.
In 1961, only shortly after the invention of the first laser, scientists exposed silicon dioxide crystals (also known as quartz) to an intense ruby laser to...
The only professorship in Germany to date, one master's programme, one laboratory with worldwide unique equipment and the corresponding research results: The University of Würzburg is leading in the field of biofabrication.
Paul Dalton is presently the only professor of biofabrication in Germany. About a year ago, the Australian researcher relocated to the Würzburg department for...
Physicists have developed an innovative method that could enable the efficient use of nanocomponents in electronic circuits. To achieve this, they have developed a layout in which a nanocomponent is connected to two electrical conductors, which uncouple the electrical signal in a highly efficient manner. The scientists at the Department of Physics and the Swiss Nanoscience Institute at the University of Basel have published their results in the scientific journal “Nature Communications” together with their colleagues from ETH Zurich.
Electronic components are becoming smaller and smaller. Components measuring just a few nanometers – the size of around ten atoms – are already being produced...
Development and implementation of an advanced automobile parking navigation platform for parking services
To fulfill the requirements of the industry, PolyU researchers developed the Advanced Automobile Parking Navigation Platform, which includes smart devices,...
20.05.2015 | Event News
18.05.2015 | Event News
12.05.2015 | Event News
29.05.2015 | Life Sciences
29.05.2015 | Earth Sciences
29.05.2015 | Physics and Astronomy