title: Cargo from tumor-expressed albumin inhibits T-cell activation and responses.
abstract: In this study, we show that rodent albumin is expressed by and cell surface localized on at least some murine tumor cells. We have been able to purify this tumor-expressed albumin from in vivo grown tumor masses. The tumor-expressed albumin, unlike normal serum albumin purified from blood, is capable of inhibiting T-cell activation, proliferation, and function in both in vitro and in vivo settings. Tumor-expressed albumin does not appear to affect antigen processing or presentation by professional antigen-presenting cells. The activity appears to lie in relatively small, lipid-like moieties that are presumably cargo for tumor-expressed albumin, and that activity can be removed from the albumin by lipid removal or treatment with lipase. Thus, we herein report of a novel form of tumor-induced immune suppression attributable to lipid-like entities, cloaked by albumin produced by tumors.
authors.affiliation: Department of Pediatrics, Steele Memorial Children's Research Center, University of Arizona, Arizona Health Sciences Center, Tucson, Arizona, USA. michael.graner@duke.edu
authors.forename: Michael W
authors.initials: MW
authors.lastname: Graner
authors.forename: Anna
authors.initials: A
authors.lastname: Likhacheva
authors.forename: Jane
authors.initials: J
authors.lastname: Davis
authors.forename: Amy
authors.initials: A
authors.lastname: Raymond
authors.forename: Jared
authors.initials: J
authors.lastname: Brandenberger
authors.forename: Angela
authors.initials: A
authors.lastname: Romanoski
authors.forename: Sylvia
authors.initials: S
authors.lastname: Thompson
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Akporiaye
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Katsanis
mesh_terms: D000418:Albumins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D008055:Lipids / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009363:Neoplasm Proteins / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology
chemical_list: D000418:Albumins; D007166:Immunosuppressive Agents; D008055:Lipids; D009363:Neoplasm Proteins; D016212:Transforming Growth Factor beta