The immune receptor Tim-3 acts as a trafficker in a Tim-3/galectin-9 autocrine loop in human myeloid leukemia cells

• Published in: Oncoimmunology Vol. 5; no. 7; p. e1195535
• Main Authors: Gonçalves Silva, Isabel, Rüegg, Laura, Gibbs, Bernhard F., Bardelli, Marco, Fruehwirth, Alexander, Varani, Luca, Berger, Steffen M., Fasler-Kan, Elizaveta, Sumbayev, Vadim V.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 02-07-2016
• Subjects: Acute myeloid leukemia; galectin-9; Original Research; Tim-3; Acute myeloid leukemia; galectin-9; Tim-3
• ISSN: 2162-4011; 2162-402X; 2162-402X
• DOI: 10.1080/2162402X.2016.1195535

The immune receptor Tim-3 is often highly expressed in human acute myeloid leukemia (AML) cells where it acts as a growth factor and inflammatory receptor. Recently, it has been demonstrated that Tim-3 forms an autocrine loop with its natural ligand galectin-9 in human AML cells. However, the pathophysiological functions of Tim-3 in human AML cells remain unclear. Here, we report for the first time that Tim-3 is required for galectin-9 secretion in human AML cells. However, this effect is cell-type specific and was found so far to be applicable only to myeloid (and not, for example, lymphoid) leukemia cells. We concluded that AML cells might use Tim-3 as a trafficker for the secretion of galectin-9 which can then be possibly used to impair the anticancer activities of cytotoxic T cells and natural killer (NK) cells.