title: Macrophages participate in host protection and the disease pathology associated with Leishmania braziliensis infection.
abstract: BACKGROUND
  Leishmania preferentially infects macrophages, which allow the parasite to multiply but can also kill the parasite. Although the T cell response in human leishmaniasis is well-characterized, little is known about the concomitant macrophage behavior. The aim of this study was to characterize the macrophage immune response after Leishmania braziliensis infection in cells derived from cutaneous leishmaniasis (CL) or mucosal leishmaniasis (ML) patients, subclinical individuals (SC) and healthy control subjects (HS).
  
  
  METHODS
  Peripheral blood mononuclear cell-derived macrophages from the different groups were exposed to L. braziliensis in vitro and were evaluated for susceptibility to Leishmania infection, ability to kill Leishmania and chemokine/cytokine production. Nitric Oxide (NO) and superoxide (O2-) levels in the supernatant of infected macrophage cultures were monitored.
  
  
  RESULTS
  After exposure to L. braziliensis, peripheral blood mononuclear cell-derived macrophages from SC individuals showed a lower infection rate and a smaller number of intracellular amastigotes compared to cells from CL and ML patients. Macrophages from CL and ML patients produced more chemokines and TNF-α than those from the SC group. Production of NO and O2- were detected but did not vary significantly among the different groups.
  
  
  CONCLUSIONS
  Our data indicate that macrophages play a pivotal role in controlling L. braziliensis infection and in leishmaniasis pathology by secreting pro-inflammatory chemokines/cytokines that activate and recruit T cells, overwhelming the inflammatory response.
authors.affiliation: Serviço de Imunologia, Complexo Hospitalar Universitário Professor Edgard Santos, Universidade Federal da Bahia, Salvador, Bahia, Brazil.
authors.forename: Angela
authors.initials: A
authors.lastname: Giudice
authors.forename: Célia
authors.initials: C
authors.lastname: Vendrame
authors.forename: Caroline
authors.initials: C
authors.lastname: Bezerra
authors.forename: Lucas P
authors.initials: LP
authors.lastname: Carvalho
authors.forename: Thaís
authors.initials: T
authors.lastname: Delavechia
authors.forename: Edgar M
authors.initials: EM
authors.lastname: Carvalho
authors.forename: Olívia
authors.initials: O
authors.lastname: Bacellar
mesh_terms: D002478:Cells, Cultured; D018925:Chemokines / Q000378:metabolism; D006801:Humans; D007892:Leishmania braziliensis / Q000276:immunology* / Q000472:pathogenicity*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000473:pathology*; D008213:Lymphocyte Activation; D008264:Macrophages / Q000276:immunology* / Q000469:parasitology*; D009569:Nitric Oxide / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D018925:Chemokines; D013481:Superoxides; D009569:Nitric Oxide