title: Novel role for galectin-1 in T-cells under physiological and pathological conditions.
abstract: Secreted, extracellular galectin-1 (exGal-1) but not intracellular Gal-1 (inGal-1) has been described as a strong immunosuppressive protein due to its major activity of inducing apoptosis of activated T-cells. It has previously been reported that T-cells express Gal-1 upon activation, however its participation in T-cell functions has remained largely elusive. To determine function of Gal-1 expressed by activated T-cells we have carried out a series of experiments. We have shown that Gal-1, expressed in Gal-1-transgenic Jurkat cells or in activated T-cells, remained intracellularly indicating that Gal-1-induced T-cell death was not a result of an autocrine effect of the de novo expressed Gal-1. Rather, a particular consequence of the inGal-1 expression was that T-cells became more sensitive to exGal-1 added either as a soluble protein or bound to the surface of a Gal-1-secreting effector cell. This was also verified when the susceptibility of activated T-cells from wild type or Gal-1 knockout mice to Gal-1-induced apoptosis were compared. Murine T-cells expressing Gal-1 were more sensitive to the cytotoxicity of the exGal-1 than their Gal-1 knockout counterparts. We also conducted a study with activated T-cells from patients with systemic lupus erythematosus (SLE), a disease in which dysregulated T-cell apoptosis has been well described. SLE T-cells expressed lower amounts of Gal-1 than healthy T-cells and were less sensitive to exGal-1. These results suggested a novel role of inGal-1 in T-cells as a regulator of T-cell response to exGal-1, and its likely contribution to the mechanism in T-cell apoptosis deficiency in lupus.
authors.affiliation: Department of Rheumatology, University of Szeged, Faculty of Medicine, Albert Szent-Györgyi Health Centre, Szeged, Hungary.
authors.forename: Magdolna
authors.initials: M
authors.lastname: Deák
authors.affiliation: Department of Rheumatology, University of Szeged, Faculty of Medicine, Albert Szent-Györgyi Health Centre, Szeged, Hungary; Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Hornung
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Julianna
authors.initials: J
authors.lastname: Novák
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Dmytro
authors.initials: D
authors.lastname: Demydenko
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Enikő
authors.initials: E
authors.lastname: Szabó
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Czibula
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Roberta
authors.initials: R
authors.lastname: Fajka-Boja
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.
authors.forename: Éva
authors.initials: É
authors.lastname: Kriston-Pál
authors.affiliation: Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary. Electronic address: monostori.eva@brc.mta.hu.
authors.forename: Éva
authors.initials: É
authors.lastname: Monostori
authors.affiliation: Department of Rheumatology, University of Szeged, Faculty of Medicine, Albert Szent-Györgyi Health Centre, Szeged, Hungary. Electronic address: kovacs.laszlo@med.u-szeged.hu.
authors.forename: László
authors.initials: L
authors.lastname: Kovács
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D016022:Case-Control Studies; D002460:Cell Line; D037483:Galectin 1 / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D019169:Jurkat Cells; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D037483:Galectin 1
keywords: Activated T-cells; Apoptosis; Intracellular galectin-1; Systemic lupus erythematosus