SIGLEC1 and infection: Clodronate treatment before and during infection selectively removed both bone marrow-derived CCR2+ inflammatory monocytes and tissue macrophages such as red pulp macrophages and CD169+ marginal metallophilic macrophages, and also partially depleted MARCO+ marginal zone macrophages, eosinophils and neutrophils (Ferenbach et al., 2012; Lundmark et al., 2013; van Rooijen et al., 1989; van Rooijen and van Nieuwmegen, 1984).