Genes associated with alternatively activated macrophages discretely regulate helminth infection and pathogenesis in experimental mouse models

Resolution of helminth infections is typically associated with the host launching a TH2 dominated immune response. In experimental models of helminth infections a key feature of this TH2 immunity is the induction of alternatively activated macrophage (AAM) populations. The importance of AAMs in immunity to helminths has initially been highlighted by the fact that their presence is essential for host survival from schistosomiasis. Since then it has become apparent that AAMs also play important roles in regulating the pathology and expulsion in a number of nematode infections. In the present review, we describe the diverse and complex roles of AAMs in regulating helminth infections and pathology. From these studies important findings are emerging on the functions of particular genes upregulated in AAM.