SIGLEC1 and infection: Even though viral replication is suppressed in the liver and allowed in CD169+ macrophages in the spleen and LNs in an IFN-I dependent manner.13 To define the role of CD169+ macrophages during infection with the noncytopathic LCMV, we first infected C57BL/6 wild-type (WT) mice with 2 × 106 plaque-forming units (PFU) of LCMV strain WE and analyzed the viral uptake.