title: Lymphocyte activation in silica-exposed workers.
abstract: Exposure to silica dust has been examined as a possible risk factor for autoimmune diseases, including systemic sclerosis, rheumatoid arthritis, systemic lupus erythematosus and ANCA-associated vasculitis. However, the underlying cellular and molecular mechanisms resulting in the increased prevalence of autoimmunity remain elusive. To clarify these mechanisms, we studied various markers of immune activation in individuals occupationally exposed to silica dust, i.e., serum levels of soluble IL-2 receptor (sIL-2R), levels of IL-2, other pro- and anti-inflammatory cytokines and lymphoproliferation. Our results demonstrate that silica-exposed individuals present important alterations in their immune response when compared to controls, as shown by increased serum sIL-2R levels, decreased production of IL-2 and increased levels of the pro-inflammatory (IFN-γ, IL-1α, TNF-α, IL-6) as well as anti-inflammatory (IL-10 and TGF-β) cytokines. Furthermore, silica-exposed individuals presented enhanced lymphoproliferative responses. Our findings provide evidence that the maintenance of immune homeostasis may be disturbed in silica-exposed individuals, possibly resulting in autoimmune disorders.
authors: Department of Pharmacology and Hemocenter, Faculty of Medical Sciences, FCM, State University of Campinas-UNICAMP, Campinas, SP, Brazil.
authors: Michelle
authors: M
authors: Rocha-Parise
authors: Department of Genetics, Neuroimmunology Unit, Evolution and Bioagents, Institute of Biology, State University of Campinas-UNICAMP, Campinas, SP, Brazil.
authors: Leonilda M B
authors: LM
authors: Santos
authors: Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands.
authors: Jan G M C
authors: JG
authors: Damoiseaux
authors: Department of Preventive and Social Medicine, Occupational Medicine Area, Faculty of Medical Sciences, FCM, State University of Campinas-UNICAMP, Campinas, SP, Brazil.
authors: Ericson
authors: E
authors: Bagatin
authors: Department of Preventive and Social Medicine, Occupational Medicine Area, Faculty of Medical Sciences, FCM, State University of Campinas-UNICAMP, Campinas, SP, Brazil.
authors: Alessandro V
authors: AV
authors: Lido
authors: Department of Pharmacology and Hemocenter, Faculty of Medical Sciences, FCM, State University of Campinas-UNICAMP, Campinas, SP, Brazil.
authors: Cristiane Okuda
authors: CO
authors: Torello
authors: Maastricht University, Maastricht, The Netherlands; Sint Franciscus Gasthuis, Rotterdam, The Netherlands.
authors: Jan W
authors: JW
authors: Cohen Tervaert
authors: Department of Pharmacology and Hemocenter, Faculty of Medical Sciences, FCM, State University of Campinas-UNICAMP, Campinas, SP, Brazil. Electronic address: mlsq@fcm.unicamp.br.
authors: Mary L S
authors: ML
authors: Queiroz
mesh_terms: D000368:Aged; D001938:Brazil; D049109:Cell Proliferation; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D015375:Receptors, Interleukin-2 / Q000097:blood; D012822:Silicon Dioxide / Q000633:toxicity*
chemical_list: D004785:Environmental Pollutants; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D012822:Silicon Dioxide
keywords: Autoimmunity; Cytokines; Interleukin-2; Lymphocytes; Silica; Soluble IL-2 receptor alpha