Monoclonal antibody CD133-2 (AC141) against hematopoietic stem cell antigen CD133 shows crossreactivity with cytokeratin 18.
CD133 is an antigen expressed on hematopoietic progenitor cells and on some epithelial cells. We previously reported that a commercially available antibody against CD133, CD133-2/AC141, also reacted with an intracellular protein in placental trophoblasts. Here we show by 2D electrophoresis and mass spectroscopy that this reactivity is with cytokeratin 18, a cytokeratin present in most simple epithelia. Immunohistochemistry (IHC) with CD133-2/AC141 on a trophoblast cell line displayed a staining pattern typical for the cytoskeleton. Cryostat sections of stratified epithelia lacking cytokeratin 18 did not react with CD133-2/AC141. In conclusion, care must be taken not to misinterpret staining patterns using CD133-2/AC141 in IHC.
Department of Anatomy, University Hospital Aachen, Aachen, Germany. apotgens@ukaachen.de
Andy J G
AJ
Pötgens
Ulrike
U
Schmitz
Peter
P
Kaufmann
Hans-Georg
HG
Frank
D000071916:AC133 Antigen; D000911:Antibodies, Monoclonal / Q000032:analysis*; D015703:Antigens, CD; D002457:Cell Extracts; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D004848:Epithelium / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007525:Isoelectric Focusing; D007633:Keratins / Q000276:immunology / Q000378:metabolism*; D010455:Peptides / Q000276:immunology / Q000378:metabolism*; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000071916:AC133 Antigen; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D002457:Cell Extracts; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; D007633:Keratins