M-CSF- and L929-derived macrophages present distinct metabolic profiles with similar inflammatory outcomes.

Macrophages are essential components of the immune system. Macrophages can be derived from the bone marrow of mice with either recombinant M-CSF or L929 supernatant. Recent literature considers recombinant M-CSF- and L929-derived macrophages as equals, even though L929-derived macrophages are exposed to other substances secreted in the L929 supernatant, and not only M-CSF. Thus, we decided to perform a comparative analysis of both inflammatory and metabolic profiles of macrophages differentiated under the aforementioned conditions, which is relevant for standardization and interpretation of in vitro studies. We observed that, when treated with LPS, L929macs secrete lower levels of proinflammatory cytokines (TNF-α, IL-6, IL12) and present higher glycolysis and oxygen consumption when compared with M-CSFmacs. L929macs also have increased mitochondrial mass, with higher percentage of dysfunctional mitochondria. This sort of information can help direct further studies towards a more specific approach for macrophage generation.