Red blood cell endothelial cells. Exposure of red blood cells to physiological levels of shear stress activates nitric oxide synthase and export of nitric oxide, which may contribute to the regulation of vascular tonus. Red blood cells can also produce hydrogen sulfide, a signalling gas that acts to relax vessel walls. It is believed that the cardioprotective effects of garlic are due to red blood cells converting its sulfur compounds into hydrogen sulfide. Red blood cells also play a part in the body's immune response: when lysed by pathogens such as bacteria, their hemoglobin releases free radicals, which break down the pathogen's cell
Genetically engineered blood Genetically engineered blood Genetically engineered blood is blood that has been modified for therapeutic or other purposes. Genetically modifying red blood stem cells allows them to produce specific therapeutic proteins on the surface or inside the cell. The stem cells are taken from mammalian bone marrow and are modified in culture. Before they become mature, mammalian red blood cells eject their genetic material. Culturing cells that produce a new protein of interest requires only a few weeks. Using the sortagging protein labeling technique, the researchers used the bacterial enzyme sortase A to establish a strong chemical bond between the surface