title: A disintegrin and metalloprotease (ADAM) 10 and ADAM17 are major sheddases of T cell immunoglobulin and mucin domain 3 (Tim-3).
abstract: T cell immunoglobulin and mucin domain 3 (Tim-3) dampens the response of CD4(+) and CD8(+) effector T cells via induction of cell death and/or T cell exhaustion and enhances the ability of macrophages to clear pathogens via binding to galectin 9. Here we provide evidence that human Tim-3 is a target of A disintegrin and metalloprotease (ADAM)-mediated ectodomain shedding resulting in a soluble form of Tim-3. We identified ADAM10 and ADAM17 as major sheddases of Tim-3 as shown by ADAM-specific inhibitors and the ADAM10 pro-domain in HEK293 cells and ADAM10/ADAM17-deficient murine embryonic fibroblasts. PMA-induced shedding of Tim-3 was abrogated by deletion of amino acids Glu(181)-Asp(190) of the stalk region and Tim-3 lacking the intracellular domain was not efficiently cleaved after PMA stimulation. Surprisingly, a single lysine residue within the intracellular domain rescues shedding of Tim-3. Shedding of endogenous Tim-3 was found in primary human CD14(+) monocytes after PMA and ionomycin stimulation. Importantly, the recently described down-regulation of Tim-3 from Toll-like receptor-activated CD14(+) monocytes was caused by ADAM10- and ADAM17-mediated shedding. Inhibition of Tim-3 shedding from lipopolysaccharide-induced monocytes did not influence lipopolysaccharide-induced TNFα and IL-6 but increases IL-12 expression. In summary, we describe Tim-3 as novel target for ADAM-mediated ectodomain shedding and suggest a role of Tim-3 shedding in TLR-mediated immune responses of CD14(+) monocytes.
authors.affiliation: From the Institute of Biochemistry, Medical Faculty, Christian-Albrechts-University, 24098 Kiel, Germany and.
authors.forename: Katja
authors.initials: K
authors.lastname: Möller-Hackbarth
authors.forename: Christin
authors.initials: C
authors.lastname: Dewitz
authors.forename: Olga
authors.initials: O
authors.lastname: Schweigert
authors.forename: Ahmad
authors.initials: A
authors.lastname: Trad
authors.forename: Christoph
authors.initials: C
authors.lastname: Garbers
authors.forename: Stefan
authors.initials: S
authors.lastname: Rose-John
authors.forename: Jürgen
authors.initials: J
authors.lastname: Scheller
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072198:ADAM17 Protein; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D019483:Disintegrins / Q000378:metabolism*; D015536:Down-Regulation; D005347:Fibroblasts / Q000378:metabolism; D037161:Galectins / Q000378:metabolism; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D000072597:Hepatitis A Virus Cellular Receptor 2; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D009000:Monocytes / Q000378:metabolism; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D019483:Disintegrins; D037161:Galectins; C448908:HAVCR2 protein, human; D000072597:Hepatitis A Virus Cellular Receptor 2; C105032:LGALS9 protein, human; D008565:Membrane Proteins; D014409:Tumor Necrosis Factor-alpha; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; C000606463:Adam17 protein, mouse
keywords: ADAM ADAMTS; Cell Culture; Cell Surface; Shedding; Signaling