Hi, I am trying to working on the "regulatory" macrophages that were originally described in the paper titled Exploring the full spectrum of macrophage activation. However, I found that another paper titled Macrophage activation and polarization: nomenclature and experimental guidelines proposed that the term "regulatory" macrophages should be avoided. I belilved that the "regulatory" macrophages that elicted immunosuppressive effects do exist as previously reported. I tried very hard to search for the new definition for this subsets of macrophages since they could not be called "regulatory" macrophages, but I could not find a satisfied answer. Also, it seemed that the M2a and M2c can also produce immunosuppresive IL-10, which quite similar to the "regulatory" macrophages.
So my questions are:
1. What is the correct nomemclature for the "regulatory" macrophages, are there any specfic markers to define this subset of macrophages in mice?
2. Are the "regulatory" macrophages equal to the IL-10-producing M2a/2c macrophages? or what is the relationship between "regulatory" macrophages and M2a/2c?
Many thanks!
So the term "regulatory" macrophages in general... does refer to M2 macrophages as a whole. The M2 phenotype can be further subsetted in humans, but not in mice.
However, IL-10, is technically not a "regulatory" cytokine. Usually, if you are talking about immunosuppression, we are talking about production of TGF-b1. (Again, this is a definition issue that I have seen throughout the years, and still persists.)
Remember, IL-10 downregulates IL-12, which can skew towards Th2, which I would considered an inflammatory response that is Th2 instead of Th1.
But for your question about the population identified in the paper, M2c technically would be the wound healing macrophages, and most likely M2a is the "regulatory" macrophage. There was another discussion about this topic on another thread.
https://www.researchgate.net/post/What_are_the_functions_of_macro-phage_M2a_M2b_and_M2c
Hope this helps.
Look here:
https://en.wikipedia.org/wiki/Regulatory_macrophages
Best regards,
Thomas
The definitions and markers for macrophage activation states are still in flux. Transcriptional regulators are still being identified. I recommed focusing on the function you want to study (eg: wound healing) rather than a particular macrophage subset.