title: A multidrug-resistance protein (MRP)-like transmembrane pump is highly expressed by resting murine T helper (Th) 2, but not Th1 cells, and is induced to equal expression levels in Th1 and Th2 cells after antigenic stimulation in vivo.
abstract: A transmembrane pump for organic anions was identified in resting murine T helper (Th) 2, but not Th1 lymphocyte cell clones, as revealed by extrusion of a fluorescent dye. Dye extrusion inhibition studies suggested that the pump may be the multidrug-resistance protein (MRP). The different expression of the pump in resting Th1 and Th2 cell clones correlated with their respective levels of MRP mRNA. The pump was inducible in Th1 cells by antigenic stimulation in vitro leading to equal expression in activated Th1 and Th2 cell clones. This suggested that dye extrusion might allow the detection of Th2 (resting or activated) or of activated Th1 cells ex vivo based on a functional parameter. To test this, mice were infected with Leishmania major parasites to activate L. major-specific T cells of either Th1 (C57BL/6 mice) or Th2 (BALB/c mice) phenotype: 2-3% of CD4+ lymph node T cells of both strains of mice extruded the dye, defining a cell subset that did not coincide with subsets defined by other activation markers. Fluorescence-activated cell-sorting revealed that the lymphokine response (Th1 or Th2, respectively) to L. major antigens was restricted to this dye-extruding subset.
authors.affiliation: Institut für Klinische Mikrobiologie und Immunologie, University of Erlangen, 91054 Erlangen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Lohoff
authors.forename: S
authors.initials: S
authors.lastname: Prechtl
authors.forename: F
authors.initials: F
authors.lastname: Sommer
authors.forename: M
authors.initials: M
authors.lastname: Roellinghoff
authors.forename: E
authors.initials: E
authors.lastname: Schmitt
authors.forename: G
authors.initials: G
authors.lastname: Gradehandt
authors.forename: P
authors.initials: P
authors.lastname: Rohwer
authors.forename: B D
authors.initials: BD
authors.lastname: Stride
authors.forename: S P
authors.initials: SP
authors.lastname: Cole
authors.forename: R G
authors.initials: RG
authors.lastname: Deeley
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis* / Q000235:genetics; D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D002999:Clone Cells; D018432:Drug Resistance, Multiple; D005456:Fluorescent Dyes / Q000378:metabolism; D016623:Ion Pumps / Q000096:biosynthesis* / Q000235:genetics; D018320:Leishmania major / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D014966:Xanthenes / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000814:Aniline Compounds; D000953:Antigens, Protozoan; D005456:Fluorescent Dyes; D016623:Ion Pumps; D014966:Xanthenes; C059715:Fluo-3