title: Effect of arsenic on regulatory T cells.
abstract: BACKGROUND
  Arsenic (As) affects the function and survival of lymphocytes, and some arsenic compounds exert a relevant antineoplastic effect. We have explored the effect of As on T regulatory cells.
  
  
  CONCLUSIONS
  In vitro experiments with peripheral blood mononuclear cells from healthy subjects showed that low concentrations of As tended to increase the number of natural T regulatory (nTreg) lymphocytes, whereas concentrations >5.0 muM had an opposite effect. Furthermore, rats exposed to As showed redistribution of nTreg cells, and As administration to rats with experimental allergic encephalomyelitis increased the levels of nTreg cells in spleen and diminished the severity of this condition. On the other hand, in 47 apparently healthy subjects chronically exposed to As, we found significant inverse correlation between urinary As levels and the number and function of nTreg lymphocytes. Although most of these individuals showed enhanced levels of apoptotic lymphocytes in peripheral blood, with a diminution of mitochondrial membrane potential, no significant correlation between these parameters and urinary As was detected.
  
  
  CONCLUSIONS
  Our data indicate that As seems to have a relevant and complex effect on nTreg cells.
authors.affiliation: Department of Immunology, Facultad de Medicina, UASLP, San Luis Potosí, SLP, México.
authors.forename: B
authors.initials: B
authors.lastname: Hernández-Castro
authors.forename: L M
authors.initials: LM
authors.lastname: Doníz-Padilla
authors.forename: M
authors.initials: M
authors.lastname: Salgado-Bustamante
authors.forename: D
authors.initials: D
authors.lastname: Rocha
authors.forename: M D
authors.initials: MD
authors.lastname: Ortiz-Pérez
authors.forename: M E
authors.initials: ME
authors.lastname: Jiménez-Capdeville
authors.forename: D P
authors.initials: DP
authors.lastname: Portales-Pérez
authors.forename: A
authors.initials: A
authors.lastname: Quintanar-Stephano
authors.forename: R
authors.initials: R
authors.lastname: González-Amaro
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D017209:Apoptosis; D001151:Arsenic / Q000494:pharmacology* / Q000652:urine; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051381:Rats; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000276:immunology; D055815:Young Adult
chemical_list: C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D001151:Arsenic