Alternatively Activated Macrophages in Types 1 and 2 Diabetes
(a) Lean individuals have AAMφs in their AT, which protect them from insulin resistance by secreting IL-10. An helminth infection can recruit Th2 lymphocytes, IL-4/13-secreting eosinophils and AAMφs, thereby increasing protection. The natural AAMφ population in the lean AT is sustained by PPARγ/δ; (b) obesity induces resistin and leptin secretion, as well as proinflammatory adipocytokines, thereby promoting CAMφ recruitment into the AT. CAMφs in turn induce insulin resistance by secreting NO and TNF-α.