Lichtgedanken 03

Rubrik 27 03 | LICHT GEDANKEN be knocking on the door of a fellow re- searcher, so that you can discuss work and swap ideas. While Alessandra Marolda, Italian doc- toral candidate at the Leibniz Institute for Natural Product Research and In- fection Biology—Hans Knöll Institute (HKI), explains her role in BLOODi, I am aware of other researchers in the lab. In the background, I can hear the eager whispering of the other project mem- bers, who are not chatting about what they did at the weekend, but are discus- sing current results from the lab. Ideally, at the end of the project it would be possible to investigate whole blood, with as little effect as possible on the blood samples, the young biologist Ma- rolda explains. Scientists have thus far been unable to do this. Nevertheless, she has already reached a small milesto- ne with her investigations in the initial stage of the project at the Centre for In- novation Competence (ZIK) Septomics. »At the beginning we do indeed inves- tigate single cells, but without marking them.« The cells are thus not stained, but are left as intact as possible, in order to produce valid results in spite of the cells having been extracted. Neutrophils react to fungus infection To this end, she took two blood samples from the same person, infecting one sample with the yeast and leaving the other as a control. »After one hour, I iso- lated neutrophil granulocytes from both samples,« says Marolda. These cells, of- ten known simply as neutrophils, are by far the most common white blood cells. »As part of the innate immune respon- se, they help to identify and destroy microorganisms—for that reason, it see- med to us promising to examine them more closely,« adds Marolda. When I make initial attempts with the laser scanning microscope, I too can see that the isolated neutrophils from the infec- ted blood can indeed be distinguished from those of the non-infected blood: their shape has altered slightly, as they are somewhat flatter. »Their morphoki- netics have been influenced by the pa- thogen,« explains Alessandra Marolda. In the next step, she is going to study, by infecting the blood samples, how the immune cells react to other fungi and bacteria: in exactly the same way? Dif- ferently? Do they only help to signal an infection or can one use their characte- ristics to identify a specific pathogen? How do other blood cells behave? In the case of sepsis, for example, starting treatment as early as possible is crucial to its success—a rapid identification of the bacteria and the appropriate medical response can, in extreme cases, mean the difference between life and death. Impressed by the significance of the in- vestigations, I leave the laboratory. The others also stop their shop talk, which Doctoral candidate Alessandra Marolda is studying neutrophil granulocytes, by comparing two blood samples from the same person. One sample is infected with the yeast Candida albicans and the other is not. Investigations using a laser scanning microscope reveal significant differences between the neutrophils from infected blood and those in the control sample. F E AT U R E