title: Schistosoma antigens downmodulate the in vitro inflammatory response in individuals infected with human T cell lymphotropic virus type 1.
abstract: Human T cell lymphotropic virus type 1 (HTLV-1) is the causal agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). While the immune response to HTLV-1 infection is polarized to the Th1-type, chronic helminth infections drive the Th2- and T regulatory-type, and are able to downregulate the inflammatory response in some autoimmune diseases.
  
  
  OBJECTIVE
  To evaluate whether Schistosoma spp. antigens alter the in vitro cytokine response in HTLV-1 infection.
  
  
  METHODS
  The recombinant Schistosoma antigens Sm29 and ShTSP2 (tetraspanin) and PIII, a fraction of the Schistosoma mansoni adult worm antigen were added to peripheral blood mononuclear cell (PBMC) cultures of HTLV-1-infected individuals and the levels of interferon (IFN)-γ and interleukin (IL)-10 in the supernatants were measured using the ELISA sandwich technique.
  
  
  RESULTS
  Compared to the levels of cytokine in nonstimulated cultures, the levels of IFN-γ were reduced in 50, 47 and 50% of patients by the presence of Sm29, ShTsp2 and PIII, respectively. The downregulation of IFN-γ production in the presence of Sm29 antigen was observed mainly in subjects who had lower basal levels of this cytokine. The levels of IL-10, however, increased by the addition of the three antigens in the cultures in 74, 62 and 44% of individuals, respectively. In addition, there was a decrease in the ratio of IFN-γ/IL-10 levels in cultures stimulated with Sm29 and ShTSP2 when compared to nonstimulated ones.
  
  
  CONCLUSIONS
  The Schistosoma spp. antigens used in this study were able to downmodulate IFN-γ production in vitro in HTLV-1 infection. This may be associated with the increased levels of IL-10 induced by the antigens.
authors.affiliation: Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador Bahia, Brazil.
authors.forename: Luciane Mota
authors.initials: LM
authors.lastname: Lima
authors.forename: Silvane Braga
authors.initials: SB
authors.lastname: Santos
authors.forename: Ricardo Riccio
authors.initials: RR
authors.lastname: Oliveira
authors.forename: Luciana Santos
authors.initials: LS
authors.lastname: Cardoso
authors.forename: Sérgio Costa
authors.initials: SC
authors.lastname: Oliveira
authors.forename: Alfredo Miranda
authors.initials: AM
authors.lastname: Góes
authors.forename: Alex
authors.initials: A
authors.lastname: Loukas
authors.forename: Edgar M
authors.initials: EM
authors.lastname: Carvalho
authors.forename: Maria Ilma
authors.initials: MI
authors.lastname: Araújo
mesh_terms: D000328:Adult; D000818:Animals; D000947:Antigens, Helminth / Q000097:blood / Q000276:immunology*; D002478:Cells, Cultured; D006800:Deltaretrovirus Infections / Q000097:blood / Q000276:immunology*; D015536:Down-Regulation / Q000276:immunology*; D005260:Female; D015368:Human T-lymphotropic virus 1 / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000276:immunology / Q000469:parasitology; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D020818:Neuroschistosomiasis; D012550:Schistosoma mansoni / Q000276:immunology* / Q000302:isolation & purification; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000469:parasitology; D018418:Th2 Cells / Q000276:immunology* / Q000469:parasitology; D055815:Young Adult
chemical_list: D000947:Antigens, Helminth; D016753:Interleukin-10; D007371:Interferon-gamma