title: Identification and clinical relevance of naturally occurring human CD8+HLA-DR+ regulatory T cells.
abstract: The lack of responsiveness to self and non-self Ags is normally maintained by multiple mechanisms, including the suppressive activities of several T cell subsets. In this study, we show that CD8(+) T cells from both adult peripheral blood and umbilical cord blood mononuclear cells constitutively expressing HLA-DR represent a natural human CD8(+) regulatory T cell subset. Their suppressive effect appears to be cell-to-cell contact dependent and may involve CTLA-4 signaling between neighboring T cells. These regulatory T cells can be expanded in vitro and exhibit a suppressive capacity similar to that observed in ex vivo CD8(+)HLA-DR(+) T cells. The high frequency of CD8(+)HLA-DR(+) T cells that we detected in patients with non-small cell lung cancer deserves further work to confirm their putative suppressor effect within the tumor.
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina;
authors.forename: Lourdes
authors.initials: L
authors.lastname: Arruvito
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina;
authors.forename: Florencia
authors.initials: F
authors.lastname: Payaslián
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina;
authors.forename: Plácida
authors.initials: P
authors.lastname: Baz
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina;
authors.forename: Ariel
authors.initials: A
authors.lastname: Podhorzer
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina;
authors.forename: Ariel
authors.initials: A
authors.lastname: Billordo
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina;
authors.forename: Julieta
authors.initials: J
authors.lastname: Pandolfi
authors.affiliation: Servicio de Neumonología, Instituto de Investigaciones Médicas Alfredo Lanari, Universidad de Buenos Aires, Buenos Aires 1427, Argentina; and.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Semeniuk
authors.affiliation: División Cirugía Torácica, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Arribalzaga
authors.affiliation: Instituto de Inmunología, Genética y Metabolismo, Hospital de Clínicas "José de San Martín," Universidad de Buenos Aires, Buenos Aires 1120, Argentina; lfainb3@gmail.com.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Fainboim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D060908:CTLA-4 Antigen / Q000276:immunology / Q000378:metabolism; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology / Q000473:pathology; D002450:Cell Communication; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D006684:HLA-DR Antigens / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D056747:Immunomodulation; D016130:Immunophenotyping; D007231:Infant, Newborn; D007376:Interleukin-2 / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism*
chemical_list: D060908:CTLA-4 Antigen; D006684:HLA-DR Antigens; D007376:Interleukin-2