Immunologists love to pigeon hole themselves and their ideas to make it simple like Th1 (Bad CD4 T cells), Th2 (Good CD4 T cells) then came Th17 (even badder CD4 T cells when we could show that Bad CD4 T cells were bad enough) but humans didnt really split that way TH0 and we have had M1 (bad macrophages) and M2 (good macrophages), which are the same cell at differnt stages of development, A1 (Bad astrocytes) and A2 (good astrocytes) which I understand were made up so the lab could define astroctyes in that way. So now we have the B10 (good B cells). A B cell that makes Interleukin 10. What about Oligodendrocytes O1 and O2 but now with RNA analysis they have been grouped O1 to O6 and the TH1 will be split in to ever decreasing subtypes.
The was no single B1 (Bad B cell) that makes interleukin 1, although B cells make interleukin 1 and B cells have been defined as B1 and B2 cells. In mice they are defined by marker but guess what. In humans they haven’t found the marker. I suspect because human and mouse B cell biology is different perhaps because they haven’t been infected and volved with Epstein Bar Virus
I am waiting now for the B17. The B17 that makes interleukin 17 thats a bad B cell
Labelling cells by cytokines is simple but it also invariably ends up being B for ollocks, as it is too simplistic. We already know there are many different B cell subsets that produce interleukin-10. It is a B cell growth and differentiation factor. Plasma cells (antibody producing B cells) that produce IL-10 are the now PC10 and then there are the regulatory B memory cells that produce IL-10 are these B10.2
Anyway the educational point of the post. When a B cell is depleted you get repopulation from the Immature B cell pool, some of these may IL-10 and they are called regulatory B cells or related cells are called transitional cells as they transition from an immatutre to a mature (naive) state. They sometimes express CD24 (a marker). However, the upshot of B cell depletion it repopulation of of cells producing IL-10 is always going to happen. So if you deplete the bad guys they are always going to repopulate into a regulated environment. So you may not need to get rid of the Badboys and girls to keep them in check.
Xiang W, Xie C, Guan Y. The identification, development and therapeutic potential of IL-10-producing regulatory B cells in multiple sclerosis. J Neuroimmunol. 2021;354:577520. doi: 10.1016/j.jneuroim.2021.577520
Regulatory B cells are a rare B-cell subset widely known to exert their immunosuppressive function via the production of interleukin-10 (IL-10) and other mechanisms. B10 cells are a special subset of regulatory B cells with immunoregulatory function that is fully attributed to IL-10. Their unique roles in the animal model of multiple sclerosis (MS) have been described, as well as their relevance in MS patients. This review specifically focuses on the identification and development of B10 cells, the signals that promote IL-10 production in B cells, the roles of B10 cells in MS, and the potential and major challenges of the application of B10-based therapies for MS.