Expanding Our Understanding of the Regulatory Macrophage

These three activated macrophages could partially rescue mice from lethal endotoxemia, and therefore we consider each to have immunoregulatory activity. This immunoregulatory activity occurred equally well in macrophages from stat6-deficient mice. The lack of STAT6 did not affect macrophages' ability to reciprocally change cytokine production or to rescue mice from lethal endotoxemia.

Furthermore, macrophages treated with IL-4 do not exhibit the immunoregulatory phenotype and associated transcriptional alterations. This work demonstrates that there are multiple ways to generate macrophages with immunoregulatory activity. These Regulatory macrophages are transcriptionally and functionally related, and quite distinct from macrophages treated with IL-4.