title: An amebic anti-inflammatory peptide down-regulates ex vivo IL-1β expression in patients with rheumatoid arthritis.
abstract: The monocyte locomotion inhibitory factor (MLIF) is a heat-stable pentapeptide produced by Entamoeba histolytica in culture. This factor displays several anti-inflammatory properties (i.e., inhibition of locomotion and respiratory burst in monocytes, reduction of skin hypersensitivity and delay of mononuclear cells in human Rebuck skin windows) with inhibition of adhesion molecules, chemokines, and other genes including interleukin-1β (IL-1β). In animal models, it reduces carragenin-induced inflammation and delays the inflammatory process in murine collagen-induced arthritis (CIA).
  
  
  OBJECTIVE
  To test, in vitro, the anti-inflammatory capacity of MLIF on a promonocytic human cell line (U-937) cells and peripheral blood mononuclear cells (PBMC) from healthy subjects and from patients with rheumatoid arthritis (RA).
  
  
  METHODS
  IL-1β gene expression was evaluated in cell cultures either in the presence of MLIF, lipopolysaccharide (LPS), or both. Relative gene expression and immunoreactivity of IL-1β were assayed in cells and supernatants, respectively.
  
  
  RESULTS
  Amebic peptide was able to down-regulate LPS-induced expression of IL-1β, in U-937 cells without a detectable effect upon the bioavailability of the cytokine. In similar culture conditions, MLIF was capable to down-regulate baseline and LPS-induced expression of IL-β only in PBMC from patients with RA. Peptide effect on immunoreactivity of IL-1β was not statistically significant.
  
  
  CONCLUSIONS
  MLIF exerts, in primed cells, exquisite anti-inflammatory properties that deserve to be explored mechanistically.
authors: Departamento de Inmunogénetica y Alergia, INER, México, D.F., Mexico. velazquez_juan@hotmail.com
authors: Juan R
authors: JR
authors: Velázquez
authors: Lizeth
authors: L
authors: Garibay-Martínez
authors: Pedro
authors: P
authors: Martínez-Tejada
authors: Yelda A
authors: YA
authors: Leal
mesh_terms: D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002460:Cell Line; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology; D008875:Middle Aged; D009842:Oligopeptides / Q000494:pharmacology / Q000627:therapeutic use*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D015415:Biomarkers; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D009842:Oligopeptides; C430647:monocyte locomotion inhibitory factor