Probing intercellular communication across immune synapses and membrane nanotubes
by
Björn Önfelt(Cell Physics, KTH, AlbaNova)
→
Europe/Stockholm
FA31
FA31
Description
Natural killer (NK) cells are an important part of the immune system since they can recognize and kill virus infected or tumor cells. NK surveillance is based on a balance between activating and inhibitory signals generated by a repertoire of cell surface receptors and ligands. A central question in NK cell recognition is how inhibitory and activating signals are integrated to determine the outcome of each interaction with a target cell. A close-up view of the encounter between NK and target cells reveals that proteins can segregate into micrometer-scale clusters at the intercellular contact, an arrangement that has been called the immune synapse (IS). The IS is believed to constitute a framework facilitating NK signal integration and effector functions such as directed secretion. Thus, comprehension of NK cell mediated immunity involves understanding the link between the response of whole cell populations and the dynamic behavior of individual cells down to the level of intracellular trafficking and organization of proteins and lipids. I want to attack this challenge by implementing new imaging methodologies where large numbers of individual cells can be monitored efficiently.
Furthermore, I will talk about membrane nanotubes, which represent a novel mechanism for long range intercellular communication in the immune system. Membrane nanotubes were recently observed to connect various types of immune cell, including NK cells, macrophages and B cells. Membrane nanotubes have been reported to facilitate several means for distal interactions between immune cells, including propagation of calcium signals, transport of membrane molecules, lipid vesicles (e.g. endosomes and lysosomes) as well as pathogens.
