Scientists have always believed that the process white blood cells undergo when they break down is random. However, a team from the La Trobe Institute of Molecular Science discovered that there is a certain order to the process, after the researchers captured the moment a white blood cell died as proof.
According to a study published in the journal Nature Communications, white blood cells eject certain molecules when they die, which then form long beaded strings of material. This material then breaks off, distributed throughout the body to contribute to defense and immunity.
Dr. Ivan Poon, one of the study's lead researchers, explained that white blood cells are central to the immune system of the body. The mechanism they observed was likened to pilots being ejected out of fighter jets when their airplane has been downed, with the molecules pushed out representing the pilots. Components that are left behind go down with the wreckage of white blood cell fragments.
The researchers called the mechanism "beaded apoptopodia," adding that proteins are implicated in the beaded strings, which can go up to eight times longer compared to the host cell they came from. The proteins affect growth and maintenance in cells as well as signal transfer.
This is the first time that the mechanism has been observed, highlighting the importance of understanding the reasons that fuel beaded apoptopodia and its role in cell fragmentation.
"It could be that we've identified the mechanics of how dying white blood cells go about alerting neighboring cells to the presence of disease or infection," suggested Poon. It is also possible that the researchers discovered a means of transporting viruses to spread infections to other parts of the body.
Programmed cell death naturally occurs in all tissues of the body as a normal part of cell development and death. The resulting fragments from dead cells are then cleared away by another natural mechanism in the body.
Professional phagocytes are white blood cells tasked with cleaning up debris from dead cells. The researchers are hopeful that gaining a better understanding of it will aid in harnessing healing and defense mechanisms in the body, translating into treatments that will pave the way for better future outcomes. They have also found drugs that can affect the process. The researchers are confident in the possibility of suppressing or enhancing the action.
Poon collaborated with Kodi Ravichandran, Mark Hulett, Suresh Mathivanan and Georgia Atkin-Smith.
