title: Allograft inflammatory factor-1/Ionized calcium-binding adapter molecule 1 is specifically expressed by most subpopulations of macrophages and spermatids in testis.
abstract: Ionized calcium-binding adapter molecule 1 (Iba1) is a 147-amino-acid calcium-binding protein widely in use as a marker for microglia. It has actin-crosslinking activity and is involved in aspects of motility-associated rearrangement of the actin cytoskeleton. The Iba1 gene and protein are identical to allograft inflammatory factor-1 (AIF-1), a protein involved in various aspects of inflammation, which was investigated independently from Iba1. Although regarded to be monocyte/macrophage-specific, expression by germ cells in testis showed that AIF-1/Iba1 is not exclusively expressed by cells of the monocyte/macrophage lineage. Furthermore, AIF-1 was found in cells not belonging to the monocyte/macrophage lineage under pathological conditions. Here, the distribution of AIF-1/Iba1 in the normal mouse has been examined, by immunohistochemistry, to determine whether AIF-1/Iba1 expression is confined to macrophages and spermatids. Spermatids are the only cells not belonging to the monocyte/macrophage lineage found to express AIF-1/Iba1 in the normal mouse, by this method. This study has not demonstrated AIF-1/Iba1 expression in dendritic cells, although this protein might be expressed by subsets of dendritic cells. AIF-1/Iba1 can be regarded a "pan-macrophage marker" because, except for alveolar macrophages, all subpopulations of macrophages examined express AIF-1/Iba1.
authors.affiliation: Institute II of Anatomy, University of Cologne, Joseph Stelzmann Strasse 9, 50931, Cologne, Germany. c.koehler@uni-koeln.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Köhler
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism; D005260:Female; D007150:Immunohistochemistry; D008264:Macrophages / Q000145:classification / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008840:Microfilament Proteins; D013087:Spermatids / Q000166:cytology / Q000378:metabolism*; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000166:cytology / Q000378:metabolism*; D014781:Viscera / Q000166:cytology / Q000378:metabolism
chemical_list: C491049:Aif1 protein, mouse; D015415:Biomarkers; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins