T cells and antibody-producing B cells carry out immune defense against specific pathogens such as viruses. Antibodies and T cell receptors are highly diverse molecules that can recognize millions of different molecules. Upon encounter of a foreign antigen (such as a molecule from the surface of a virus), T cells and B cells whose receptors match that particular antigen expand dramatically, providing the immune system with a large number of very specific defenders. After an attack is fought off, the overall numbers of specific T and B cells go down again, but a few of them become long-lived so-called "memory cells" that ensure a quick re-mobilization should the same type of attacker strike again.
T cells consist of two major groups: CD4-positive T helper cells (who help other immune cells in mounting an effective response) and CD8-positive killer T cells. HIV infects and destroys CD4-positive cells, leaving patients with a crippled immune system. Throughout the course of HIV disease, however, patients have high levels of HIV-specific killer T cells. Early after initial infection, these cells are able to effectively kill the virus and reduce viral load. On the other hand, during the later stage of disease killer T cells, while still present, seem no longer able to control the virus. In an article in the November 4 issue of the Journal of Clinical Investigation, Premlata Shankar and colleagues from the Center for Blood Research at Harvard Medical School suggest why this might be the case.
The researchers compared killer T cells from HIV infected asymptomic individuals with those from symptomatic AIDS patients. They examined the killer cells ability to eliminate target cells infected with laboratory strains of HIV on one hand, and with autologous virus (isolated from the patient) on the other. What they found is that killer T cells from asymptomatic individuals can recognize and kill both types of target cells. In contrast, the killer T cells from symptomatic patients, while still able to recognize and eliminate the laboratory strain targets, no longer killed target cells that were infected with their own, autologous, virus. This is likely due to the virus propensity to mutate and the in inability of the patients weakened immune system to keep up with the changing virus.
Brooke Grindlinger | EurekAlert!
TSRI researchers develop new method to 'fingerprint' HIV
29.03.2017 | Scripps Research Institute
Periodic ventilation keeps more pollen out than tilted-open windows
29.03.2017 | Technische Universität München
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences