Malaria parasite impairs key immune system cells
Plasmodium, the parasite responsible for malaria, impairs the ability of key cells of the immune system to trigger an efficient immune response. This might explain why patients with malaria are susceptible to a wide range of other infections and fail to respond to several vaccines.
In a study published today in the open access journal Journal of Biology, researchers show that if dendritic cells, the key cells involved in initiating immunity, are exposed to red blood cells infected with Plasmodium chabaudi, they initiate a sequence of events that result in compromised antibody responses. The researchers show that this is due to the presence of hemozoin, a by-product of the digestion of hemoglobin by Plasmodium, in infected red blood cells. These observations also explain why vaccines for many diseases are so ineffective during malaria infection, and suggest that the use of preventive anti-malarial drugs before vaccination may improve vaccine-induced protection.
In a study funded by the Wellcome Trust, Owain Millington and colleagues from the University of Strathclyde, UK, studied the effects of Plasmodium chabaudi, the mouse Plasmodium, on mice antigen-presenting dendritic cells in culture and confirmed their findings in live mice.
Millington et al.’s results show that dendritic cells exposed to P. chabaudi–infected red blood cells do not activate normally. They express lower levels of membrane molecules that stimulate other cells of the immune system, and their cytokine production is lower than that of normal dendritic cells. Millington et al. demonstrate that this is caused by exposure to hemozoin present in infected red blood cells.
Millington et al. then show that P.chabaudi-infected dendritic cells fail to activate helper T cells properly – T cells are activated but show reduced proliferation and cytokine production in culture. Importantly, during malaria infection, T cells fail to migrate to B-cell areas of lymph nodes or spleen, and this results in the failure of B-cell activation and antibody production.
Juliette Savin | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers
Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...
Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.
At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...