We live in a world full of risks, many of which are invisible. Fortunately, we did not go this dangerous road alone. There are precious sentinel cells lying in our bodies, and every day they are fighting to keep us alive.
The work of the human immune system is huge and complex. That’s why, despite decades of research, scientists are still working to reveal the full working principle.
Recently, scientists from the University of Queensland collected real-time footage of structures of immune cells for the first time, called “tent-pole ruffles,” which we did not know before.
“It’s really exciting to be able to observe cell behavior at an unprecedented level of resolution,” said co-author Adam Wall, a molecular biology researcher at the University of Queensland. “Through microscopic imaging technology, we also need to understand how cells work.”
Tent-pole ruffles are located on the surface of some white blood cells called macrophages that detect and engulf cell debris, microbes, cancer cells and foreign bodies in the body. The role of these ruffles is to help macrophages swallow the surrounding fluid to cope with any potential threat. The structure is named because their protrusions look like tent poles with a special membrane between them called ruffle sheath extensions. This unique shape makes these immune cells an ideal tool for phagocytizing large volumes of liquid samples, which scientists call “macropinocytosis.”
The invention of the lattice light sheet microscope made it possible to discover these structures, which can capture a large number of 3D images with extremely high precision in a few seconds. When invasive cancer cells are present in the body, they use the process of giant cell drinking to engulf nutrients in the body, enabling them to survive and reproduce. Like macrophages, these cancer cells also form tent-pole ruffles on their surface to improve this mechanism.
If scientists can figure out how to target these structures, in theory, they can stop cancer cells from surviving. “This imaging will give us a tool to reveal how cell behavior is affected by a disease. In addition, testing the effects of drugs on cells can provide us with insights that are important for designing new therapies,” the authors say.
The authors hope that through the new lattice light sheet microscope, they can further explore the complexity of the human immune system. The study was published in the Journal of Cell Biology.
Nicholas D. Condon, John M. Heddleston, Teng-Leong Chew, et al. Macropinosome formation by tentpole ruffling in macrophages. J Cell Biol. 2018 Aug 27. pii: jcb.201804137. doi: 10.1083/jcb.201804137