IL4 and infection: Because this phenotype is observed at peak infection and through clearance of organisms from the lung, it is possible that alternatively activated macrophages contribute to resolution of P. murina. Consistent with this, the β-glucan receptor Dectin-1 and MR have both been implicated in host defense against PC [55,56] and are both upregulated in IL-4/IL-13 driven alternative activation of macrophages [57,58,59].