111Indium-labeled human alveolar macrophages and monocytes: Function and ultrastructure

Human alveolar macrophages and peripheral blood mononuclear cells were labeled with indium-111 (¹¹¹In)-oxine in ethanol. The efficiency of labeling averaged 84% for macrophages and 74% for mononuclear cell preparations. Phagocytosis by macrophages, the release of colony stimulating factor activity (CSF) by macrophages, and chemotaxis by monocytes in response to human C5-derived chemotactic factor (C5_fr) and formyl-methionyl-leucyl-phenylalanine (f-MLP), were indistinguishable between labeled and unlebeled cells. Microscopically, lebeled cells looked similar to control cells. Radioautography demonstrated ¹¹¹In throughout the labeled cells, but there was a disproportionately high quantity over nuclei. These findings add to the growing literature indicating that ¹¹¹In labels cells efficiently and that cells can retain function after being labeled with ¹¹¹In.