Immunity system complexity: monocytes to the rescue (Introduction)

by David Turell , Sunday, March 19, 2023, 15:23 (403 days ago) @ David Turell

They proliferate to help tissue infections:

https://www.sciencedaily.com/releases/2023/03/230317144955.htm

"The ability of a cell to divide, to proliferate, is essential for life and gives rise to the formation of complex organisms from a single cell. It also allows the replacement of used cells from a limited number of "stem" cells, which then proliferate and specialize...Researchers from the GIGA Institute at the University of Liège have discovered that, in a healthy individual, certain blood immune cells, the monocytes, also have this ability to proliferate, with the aim to replace tissue macrophages, which are essential for the proper functioning of our body.

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"Research Institute) and his team from the GIGA Institute at ULiège discovered that this ability to proliferate is not merely restricted to stem cells, but is also an as-yet-unknown function of blood immune cells, the monocytes. Indeed, blood monocytes, previously considered as differentiated cells, are capable of proliferating and generating a pool of monocytes in the tissues in order to give rise to macrophages, which are important immune cells that protect us against microbes and support the proper functioning of our organs.

"'This is a major fundamental discovery, which changes our conception of the involvement of cell proliferation in the constitution and maintenance of our immune system." explains Thomas Marichal, director of the study. "Our finding also suggests that the information that can be drawn from an enumeration of blood monocytes, classically carried out during a blood test, would reflect only little of what is happening at the level of the tissues, during 'infection or inflammation, for example, since monocytes can proliferate when they enter tissues." He also adds: "Fortunately, this proliferation is extremely well controlled and does not lead to a tumoral process. It has only one goal: to allow, as effectively as possible, the replacement of immune cells that populate our tissues: the macrophages.'"

Comment: A backup design to reinforce macrophages in infected tissues. This is another level of protection. Normally only stem cells can produce a needed cell type. Monocytes must be DNA coded to do this.