The cell that engulfs the cell of a foreign object is called a phagocyte. Phagocytes perform a number of tasks in the body such as removing waste from the body, keeping our immune system working properly, and removing infectious particles from the bloodstream.
In the previous chapter we learned that neutrophils are highly specialized cells that fight infection, and that phagocytosis is the process that allows neutrophils to get rid of bacteria and other foreign particles. Neutrophils do this by engulfing foreign cells, breaking them up into pieces, and then releasing them to be destroyed by other cells. But neutrophils are not the only cells that perform this process.
If you’re a fan of the TV show “The X-Files” you already know that neutrophils perform phagocytosis, and we’ve already seen how neutrophils recycle waste and release it to the environment when they’re not performing this process. (You know, like if they’re dead and they’re not recycling any waste.) As part of their cleanup process they also remove damaged cells from the bloodstream which makes them even less efficient.
I think neutrophils are the most likely suspects in this mess, but they don’t appear to be the only ones who do this. We have seen neutrophils perform phagocytosis in the past without any problems.
If you recall from our previous article on neutrophils, neutrophils are very similar to macrophages, but they are not as efficient at phagocytosis. Macrophages are the cell that engulf and digest foreign antigens, and neutrophils are the cell that engulfs and degrades dying tissue and its wastes. When neutrophils are killed in the first place, they may not be able to perform this cleaning job.
Neutrophils are a common source of infections. They are the cells that kill harmful pathogens and bacteria on our skin. If you have to put on a bandage to go to the bathroom, you’re probably not going to be doing it without breaking out the antibiotic cream. When neutrophils die, they release their waste products and phagocytes take in the cells and carry them off.
It’s the same process as the ones that kill any other white blood cells, but with a higher-tech twist. Neutrophil killers work by using specialized cell-killing molecules called granzymes to destroy the cells. The granzymes are actually proteins that can be found in the neutrophil and are released when the neutrophil dies. When they die they can be found in the form of granules.
I wonder if neutrophils (or any other white blood cells for that matter) would be better off if they were able to carry the granules around in tiny bags.
It is a good point, but I think neutrophils are a good example of a cell type that is not as good at killing itself. It would be better if white blood cells were able to carry around a granule bag that would kill the cell.
The phagocytosis is a form of intracellular killing. I’ll be honest, it seems an awful lot like a granule bag. Like with your granules, your white blood cells will be much better at killing itself if they are able to carry around a bag of granules. It’s not perfect, but it would be nice if we could at least think about it.