| First Author | La Flamme AC | Year | 2012 |
| Journal | PLoS One | Volume | 7 |
| Issue | 10 | Pages | e46989 |
| PubMed ID | 23071691 | Mgi Jnum | J:192088 |
| Mgi Id | MGI:5464028 | Doi | 10.1371/journal.pone.0046989 |
| Citation | La Flamme AC, et al. (2012) Type II-activated murine macrophages produce IL-4. PLoS One 7(10):e46989 |
| abstractText | BACKGROUND: Type II activation of macrophages is known to support Th2 responses development; however, the role of Th2 cytokines (esp. IL-4) on type II activation is unknown. To assess whether the central Th2 cytokine IL-4 can alter type II activation of macrophages, we compared the ability of bone marrow-derived macrophages from wild type (WT) and IL-4Ralpha-deficient mice to be classically or type II-activated in vitro. RESULTS: We found that although both WT and IL-4Ralpha-deficient macrophages could be classically activated by LPS or type II activated by immune complexes plus LPS, IL-4Ralpha-deficient macrophages consistently produced much higher levels of IL-12p40 and IL-10 than WT macrophages. Additionally, we discovered that type II macrophages from both strains were capable of producing IL-4; however, this IL-4 was not responsible for the reduced IL-12p40 and IL-10 levels produced by WT mice. Instead, we found that derivation culture conditions (GM-CSF plus IL-3 versus M-CSF) could explain the different responses of BALB/c and IL-4Ralpha-/- macrophages, and these cytokines shaped the ensuing macrophage such that GM-CSF plus IL-3 promoted more IL-12 and IL-4 while M-CSF led to higher IL-10 production. Finally, we found that enhanced IL-4 production is characteristic of the type II activation state as other type II-activating products showed similar results. CONCLUSIONS: Taken together, these results implicate type II activated macrophages as an important innate immune source of IL-4 that may play an important role in shaping adaptive immune responses. |
