title: Circulating T regulatory cells migration and phenotype in glioblastoma patients: an in vitro study.
abstract: Glioblastoma multiforme (GBM) is the most aggressive primary human brain tumor. The relatively high amount of T regulatory lymphocytes present in the tumor, contributes to the establishment of an immunosuppressive microenvironment. Samples of peripheral blood were collected from GBM patients and healthy controls and a purified population of Treg (CD4(+)/CD25(bright)) was isolated using flow cytometric cell sorting. Treg migrating capacities toward human glioma cell line conditioned medium were evaluated through an in vitro migration test. Our data show that supernatants collected from GBM cell lines were more attractant to Treg when compared to complete standard medium. The addition of an anti-CCL2 antibody to conditioned medium decreased conditioned medium-depending Treg migration, suggesting that CCL2 (also known as Monocyte Chemoattractant Protein, MCP-1) is implicated in the process. The number of circulating CD4(+)/μL or Treg/μL was similar in GBM patients and controls. Specific Treg markers (FOXP3; CD127; Helios; GITR; CTLA4; CD95; CCR2, CCR4; CCR7) were screened in peripheral blood and no differences could be detected between the two populations. These data confirm that the tumor microenvironment is attractive to Treg, which tend to migrate toward the tumor region changing the immunological response. Though we provide evidence that CCL2 is implicated in Treg migration, other factors are needed as well to provide such effect.
authors.affiliation: Laboratory of Clinical Pathology and Medical Genetics, Foundation IRCCS Neurological Institute C. Besta, Via Celoria, 11, 20133, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Vasco
authors.forename: Alessandra
authors.initials: A
authors.lastname: Canazza
authors.forename: Ambra
authors.initials: A
authors.lastname: Rizzo
authors.forename: Adele
authors.initials: A
authors.lastname: Mossa
authors.forename: Elena
authors.initials: E
authors.lastname: Corsini
authors.forename: Antonio
authors.initials: A
authors.lastname: Silvani
authors.forename: Laura
authors.initials: L
authors.lastname: Fariselli
authors.forename: Andrea
authors.initials: A
authors.lastname: Salmaggi
authors.forename: Emilio
authors.initials: E
authors.lastname: Ciusani
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D002469:Cell Separation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D005909:Glioblastoma / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger