title: Immunomodulatory activity of Tityus serrulatus scorpion venom on human T lymphocytes.
abstract: BACKGROUND
  Tityus serrulatus scorpion venom (TsV) contains toxins that act on K(+) and Na(+) channels and account for the venom's toxic effects. TsV can activate murine peritoneal macrophages, but its effects on human lymphocytes have been poorly investigated. Considering that lymphocytes may play an important role in envenomation, we assessed whether TsV affects the expression of phenotypic (CD3, CD4, and CD8) and activation (CD69, CD25, and HLA-DR) markers, cell proliferation, and cytokine production in peripheral blood mononuclear cells.
  
  
  METHODS
  Cytotoxicity of TsV was evaluated via the MTT assay. Cell proliferation, expression of phenotypic and activation markers, and release of cytokines were assessed using flow cytometry, after treatment with non-cytotoxic concentrations of TsV. The combined use of carboxyfluorescein diacetate succinimidyl ester and monoclonal antibodies against phenotypic and activation markers enabled us to simultaneously assess cell proliferation extent and cell activation status, and to discriminate among cell subpopulations.
  
  
  RESULTS
  TsV at concentrations of 25 to 100 μg/mL were not cytotoxic towards peripheral blood mononuclear cells. TsV did not induce significant changes in lymphocyte subpopulations or in the expression of activation markers on CD4(+) and CD8(+) T cells. TsV inhibited the phytohemagglutinin-stimulated lymphocyte proliferation, particularly in the CD8(+) CD25(+) T lymphocyte subset. TsV alone, at 50 and 100 μg/mL, did not induce peripheral blood mononuclear cell proliferation, but elicited the production and release of IL-6, a proinflammatory cytokine that plays an important role in innate and adaptive immune responses.
  
  
  CONCLUSIONS
  TsV is a potential source of molecules with immunomodulatory action on human T lymphocytes.
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Andrea
authors.initials: A
authors.lastname: Casella-Martins
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil ; Department of Pharmaceutical Sciences, Federal University of Espírito Santo, Vitória, ES Brazil.
authors.forename: Lorena R
authors.initials: LR
authors.lastname: Ayres
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Burin
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Fabiana R
authors.initials: FR
authors.lastname: Morais
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Juliana C
authors.initials: JC
authors.lastname: Pereira
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Lucia H
authors.initials: LH
authors.lastname: Faccioli
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Suely V
authors.initials: SV
authors.lastname: Sampaio
authors.affiliation: Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP Brazil.
authors.forename: Eliane C
authors.initials: EC
authors.lastname: Arantes
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Fabiola A
authors.initials: FA
authors.lastname: Castro
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto, SP CEP 14040-903 Brazil.
authors.forename: Luciana S
authors.initials: LS
authors.lastname: Pereira-Crott
keywords: Cell proliferation; Cytokine; Immunomodulation; Immunophenotyping; T lymphocyte; Tityus serrulatus venom