title: Reciprocal expression of the TNF family receptor herpes virus entry mediator and its ligand LIGHT on activated T cells: LIGHT down-regulates its own receptor.
abstract: The TNF receptor (TNFR) family plays a central role in the development of the immune response. Here we describe the reciprocal regulation of the recently identified TNFR superfamily member herpes virus entry mediator (HVEM) (TR2) and its ligand LIGHT (TL4) on T cells following activation and the mechanism of this process. T cell activation resulted in down-regulation of HVEM and up-regulation of LIGHT, which were both more pronounced in CD8(+) than CD4(+) T lymphocytes. The analysis of HVEM and LIGHT mRNA showed an increase in the steady state level of both mRNAs following stimulation. LIGHT, which was present in cytoplasm of resting T cells, was induced both in cytoplasm and at the cell surface. For HVEM, activation resulted in cellular redistribution, with its disappearance from cell surface. HVEM down-regulation did not rely on de novo protein synthesis, in contrast to the partial dependence of LIGHT induction. Matrix metalloproteinase inhibitors did not modify HVEM expression, but did enhance LIGHT accumulation at the cell surface. However, HVEM down-regulation was partially blocked by a neutralizing mAb to LIGHT or an HVEM-Fc fusion protein during activation. As a model, we propose that following stimulation, membrane or secreted LIGHT binds to HVEM and induces receptor down-regulation. Degradation or release of LIGHT by matrix metalloproteinases then contributes to the return to baseline levels for both LIGHT and HVEM. These results reveal a self-regulating ligand/receptor system that contributes to T cell activation through the interaction of T cells with each other and probably with other cells of the immune system.
authors.affiliation: Laboratoire d'Immunologie des Tumeurs, Département d'Hématologie, Institut Paoli Calmettes, Université de la Méditerranée, Marseille, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Morel
authors.forename: J M
authors.initials: JM
authors.lastname: Schiano de Colella
authors.forename: J
authors.initials: J
authors.lastname: Harrop
authors.forename: K C
authors.initials: KC
authors.lastname: Deen
authors.forename: S D
authors.initials: SD
authors.lastname: Holmes
authors.forename: T A
authors.initials: TA
authors.lastname: Wattam
authors.forename: S S
authors.initials: SS
authors.lastname: Khandekar
authors.forename: A
authors.initials: A
authors.lastname: Truneh
authors.forename: R W
authors.initials: RW
authors.lastname: Sweet
authors.forename: J A
authors.initials: JA
authors.lastname: Gastaut
authors.forename: D
authors.initials: D
authors.lastname: Olive
authors.forename: R T
authors.initials: RT
authors.lastname: Costello
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000821:virology; D002469:Cell Separation; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D015536:Down-Regulation / Q000276:immunology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008024:Ligands; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000502:physiology; D018613:Microscopy, Confocal; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D053240:Receptors, Tumor Necrosis Factor, Member 14; D011991:Receptors, Virus / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D018139:Simplexvirus / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D053326:Tumor Necrosis Factor Ligand Superfamily Member 14; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015854:Up-Regulation / Q000276:immunology
chemical_list: D004791:Enzyme Inhibitors; D008024:Ligands; D008565:Membrane Proteins; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D018124:Receptors, Tumor Necrosis Factor; D053240:Receptors, Tumor Necrosis Factor, Member 14; D011991:Receptors, Virus; C506028:TNFRSF14 protein, human; C505914:TNFSF14 protein, human; D053326:Tumor Necrosis Factor Ligand Superfamily Member 14; D014409:Tumor Necrosis Factor-alpha; D003513:Cycloheximide; D008666:Metalloendopeptidases