infection (Brooks et al., 2006; Ejrnaes et al., 2006; Moore et al., 2001). IL-10 is expressed by T helper 2 (Th2) cells, B cells, DCs, and macrophages (Moore et al., 2001), and also by Th1 cells (Anderson et al., 2007; Assenmacher et al., 1994; Del Prete et al., 1993; Gerosa et al., 1996; Jankovic et al., 2007; Pohl-Koppe et al., 1998) and (reviewed in O'Garra