After a break in antiretroviral drug therapy in HIV-positive patients, the virus rebounds and begins to multiply. While this was feared to destroy, perhaps irreversibly, patient HIV-specific CD4+ T cells that are preferentially infected by the virus, it has now be shown to actually boost HIV-specific T cell production and activation, thereby boosting the immune response to the virus.
Scheduled interruption and resumption of antiretroviral treatment of HIV-positive patients has generated hopes of reducing drug toxicities, costs, and total treatment time. However there has been concern regarding how this on and off cycling of drug therapy effects viral replication and the patients ongoing immune response to viral infection. While it was implied that even at high viral loads a small population of these HIV-specific CD4+ T cells remained, they have been difficult to quantify.
Rodney Phillips and colleagues from the University of Oxford developed a highly sensitive technique to visualize, quantify, and track the HIV-specific CD4+ T cell population in patients with early-stage HIV infection who were given a short, fixed course of antiretroviral therapy. They found that return of viral replication after cessation of treatment does not destroy this important T cell population – their numbers were in fact comparable to the numbers observed during therapy. Furthermore, the turnover of these virus-specific cells was increased and the CD4+ T cells were prompted to mature into what are known as effector cells, capable of exerting an immune function that helps coordinate other cells of the immune system to eliminate the virus.
Brooke Grindlinger | EurekAlert!
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy