title: Plant lectins ConBr and CFL modulate expression toll-like receptors, pro-inflammatory cytokines and reduce the bacterial burden in macrophages infected with Salmonella enterica serovar Typhimurium.
abstract: BACKGROUND
  Plant lectins have long been used in biomedical research as immunomodulators against tumor cells and microbial infections.
  
  
  OBJECTIVE
  To test the ability of plant lectins ConBr (Canavalia brasiliensis) and CFL (Cratylia argentea) to activate antimicrobial and immunomodulatory activities of murine peritoneal macrophages (pMØ) infected with a virulent strain of Salmonella enterica serovar Typhimurium (STm).
  
  
  METHODS
  We incubated pMØ with non-toxic amounts of ConBr and CFL either before (preventive schedule) or after (curative schedule) exposure to STm.
  
  
  RESULTS
  In uninfected pMØ, ConBr and CFL greatly increased levels of mRNA transcripts for IL-1β, TNF-α and IL-6 and the inducible nitric oxide synthase (iNOs), but not IL-10 and IL-12. Exposure to naïve splenocytes of culture supernatants of pMØ previously stimulated with CFL resulted in expression of IL-12 and IFN-γ. Both preventive and curative treatment schedules significantly reduced the intracellular load of Salmonella. Experiments in infected macrophages exposed to lectins in the preventive schedule showed that mRNA transcripts for IL-6 and TNF-α were increased by CFL, whereas ConBr enhanced IL-12 (subunit p40). In the curative schedule, CFL induced significant expression of IL-12 (p40) whereas ConBr enhanced expression IL-1β and TNF-α genes. The lectin treatments did not influence on iNOs expression in pMØ infected with STm C5 regardless of the treatment schedule. Curative treatments with CFL increased approximately 130-fold expression of TLR-4 whist expression of TLR-9 was increased by treatments with ConBr.
  
  
  CONCLUSIONS
  We conclude that lectins ConBr and CFL have immunomodulatory properties that are beneficial on control of cells infected by Salmonella.
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil.
authors.forename: Jec
authors.initials: J
authors.lastname: Batista
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Ralph
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil.
authors.forename: R V
authors.initials: RV
authors.lastname: Vaz
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil.
authors.forename: Pfc
authors.initials: P
authors.lastname: Souza
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza-CE, Brazil.
authors.forename: A B
authors.initials: AB
authors.lastname: Silva
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil.
authors.forename: Dco
authors.initials: D
authors.lastname: Nascimento
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil.
authors.forename: L T
authors.initials: LT
authors.lastname: Souza
authors.affiliation: Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza-CE, Brazil.
authors.forename: M V
authors.initials: MV
authors.lastname: Ramos
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES United Kingdom. Electronic address: pm274@cam.ac.uk.
authors.forename: P
authors.initials: P
authors.lastname: Mastroeni
authors.affiliation: Department of Biology, Federal Rural University of Pernambuco, Recife-PE, CEP 52171-900 Brazil. Electronic address: jvitormlf@yahoo.com.br.
authors.forename: J V
authors.initials: JV
authors.lastname: Lima-Filho
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D032449:Canavalia / Q000737:chemistry; D016207:Cytokines / Q000378:metabolism*; D007887:Fabaceae / Q000737:chemistry*; D007155:Immunologic Factors / Q000494:pharmacology / Q000627:therapeutic use; D007249:Inflammation / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D008517:Phytotherapy; D037121:Plant Lectins / Q000494:pharmacology* / Q000627:therapeutic use; D012480:Salmonella Infections / Q000188:drug therapy / Q000378:metabolism / Q000382:microbiology; D012486:Salmonella typhimurium / Q000187:drug effects*; D065288:Serogroup; D015398:Signal Transduction / Q000187:drug effects; D051193:Toll-Like Receptors / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D007155:Immunologic Factors; D053583:Interleukin-1beta; D015850:Interleukin-6; D037121:Plant Lectins; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; C039268:lectin, Canavalia; D018664:Interleukin-12; D052247:Nitric Oxide Synthase Type II
keywords: C. argentea; C. brasiliensis; Immunomodulators; Mannose-binding