The multidrug resistance protein 1: a functionally important activation marker for murine Th1 cells.
Previously, we described the expression of an energy-dependent pump in resting murine Th2 (but not resting Th1) cells which extruded the fluorescent dye Fluo-3. After stimulation with Ag and APCs, Th1 cells also expressed this pump. Furthermore, expression of the murine multidrug resistance protein 1 (mrp1) correlated with the presence of the pump. In this study, we report that Fluo-3 is indeed transported by murine mrp1 or its human ortholog MRP1, as revealed by transfection of HEK 293 cells with mrp1 or MRP1 cDNA. Like antigenic activation, IL-2 dose-dependently enhanced the Fluo-3-extruding activity in murine Th1 cells. Although TNF-alpha and IL-12 by themselves only weakly enhanced Fluo-3 extrusion, each of them did so in strong synergism with IL-2. An Ab directed against mrp1 was used to quantify the expression of mrp1 protein in T cells at the single-cell level. Like the Fluo-3 pump, mrp1 protein expression was enhanced by IL-2. Immunohistochemical studies using confocal laser microscopy indicated that mrp1 is localized mainly at the plasma membrane. In addition, protein expression of mrp1 was induced in Vbeta8+CD4+ T cells 12 h after in vivo application of Staphylococcal enterotoxin B. Finally, mrp1 was functionally relevant during the activation process of Th1 cells, because T cell activation could be suppressed by exposure of cells to the mrp1 inhibitor MK571. Thus, we present mrp1 as a novel, functionally important activation marker for Th1 cells and short-term in vivo activated CD4+ T cells, whereas its expression seems to be constitutive in Th2 cells.
Prechtl
S
S
Institut für Klinische Mikrobiologie und Immunologie, Universität Erlangen, Erlangen, Germany. p.stefan@excite.com
Roellinghoff
M
M
Scheper
R
R
Cole
S P
SP
Deeley
R G
RG
Lohoff
M
M
D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D001692:Biological Transport / Q000235:genetics / Q000276:immunology; D015415:Biomarkers; D015496:CD4-Positive T-Lymphocytes / Q000737:chemistry; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D018076:DNA, Complementary / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics / Q000276:immunology*; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D016623:Ion Pumps / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011422:Propionates / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D013194:Staining and Labeling; D018089:Superantigens / Q000494:pharmacology; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D014162:Transfection; D015854:Up-Regulation / Q000276:immunology; D014966:Xanthenes / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; D000814:Aniline Compounds; D015415:Biomarkers; D016207:Cytokines; D018076:DNA, Complementary; D005456:Fluorescent Dyes; D007166:Immunosuppressive Agents; D016623:Ion Pumps; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011422:Propionates; D011804:Quinolines; D018089:Superantigens; D014966:Xanthenes; C059715:Fluo-3; C059141:verlukast