Anti-ACE2 Antibody

Researcher Contributions

• The protein expression profile of ACE2 in human tissuesThe Human Protein Atlas (proteinatlas.org)2020-04-21Feria Hikmet*, Loren Méar*, Mathias Uhlén**, Cecilia Lindskog*

  *Uppsala University, Department of Immunology, Genetics and Pathology, Uppsala, Sweden
  **Science for Life Laboratory, School of engineering Sciences in Chemistry, Biotechnology and health, KTH - Royal Institute of Technology, Stockholm, Sweden and Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden 
  
  Abstract
  The international spread of the novel, pathogenic SARS-coronavirus 2 (SARS-CoV-2) poses a global challenge on both healthcare and society. A multitude of research efforts worldwide aim at characterizing the cellular factors involved in viral transmission in order to reveal therapeutic targets. For a full understanding of the susceptibility for SARS-CoV-2 infection, the cell type-specific expression of the host cell surface receptor is necessary. The key protein suggested to be involved in host cell entry is Angiotensin I converting enzyme 2 (ACE2), and its expression has been reported in various human organs, in some cases with inconsistent or contradictory results. Here, we aim to verify a reliable expression profile of ACE2 in all major human tissues and cell types. Based on stringently validated immunohistochemical analysis and high-throughput mRNA sequencing from several datasets, we found that ACE2 expression is mainly localized to microvilli of the intestinal tract and renal proximal tubules, gallbladder epithelium, testicular Sertoli cells and Leydig cells, glandular cells of seminal vesicle and cardiomyocytes. The expression in several other previously reported locations, including alveolar type II (AT2) cells, could not be confirmed. Furthermore, ACE2 expression was absent in the AT2 lung carcinoma cell line A549, often used as a model for viral replication studies. Our analysis suggests that the expression of ACE2 in the human respiratory system appears to be limited, and the expression of the receptor in lung or respiratory epithelia on the protein level is yet to be confirmed. This raises questions regarding the role of ACE2 for infection of human lungs and highlights the need to further explore the route of transmission during SARS-CoV-2 infection.

  

  Cell type-specific localization of ACE2 in human tissues based on immunohistochemistry.

  Representative images of 18 tissue types and histological structures stained with immunohistochemistry using the polyclonal rabbit antibody HPA000288 (Atlas Antibodies AB), targeting human ACE2 protein (brown), and counterstained with hematoxylin (blue). Highest ACE2 expression was observed in microvilli of the intestinal tract and renal proximal tubules, in membranes of gallbladder epithelium, testicular Sertoli cells and Leydig cells, a subset of glandular cells in seminal vesicle (arrowheads), and in cytoplasm cardiomyocytes. Note that ACE2 protein expression was not detected in the lower parts of the mucosal intestinal layer. No protein expression was observed in lung, bronchus, nasopharynx, esophagus, stomach, endometrium, smooth muscle tissue (visualized in muscle layer of small intestine), spleen, cerebral cortex, adipose tissue or different structures of the skin. Protein expression was neither detected in endothelial cells, here shown in cerebral cortex (arrow), nor in fibroblasts, here sown in dermis layer of skin (arrows). For details, see https://www.proteinatlas.org/ENSG00000130234-ACE2/tissue.

  Full text: 
  bioRxiv preprint
  https://www.biorxiv.org/content/10.1101/2020.03.31.016048v1.full