title: Human severe sepsis cytokine mixture increases β2-integrin-dependent polymorphonuclear leukocyte adhesion to cerebral microvascular endothelial cells in vitro.
abstract: BACKGROUND
  Sepsis-associated encephalopathy (SAE) is a state of acute brain dysfunction in response to a systemic infection. We propose that systemic inflammation during sepsis causes increased adhesion of leukocytes to the brain microvasculature, resulting in blood-brain barrier dysfunction. Thus, our objectives were to measure inflammatory analytes in plasma of severe sepsis patients to create an experimental cytokine mixture (CM), and to use this CM to investigate the activation and interactions of polymorphonuclear leukocytes (PMN) and human cerebrovascular endothelial cells (hCMEC/D3) in vitro.
  
  
  METHODS
  The concentrations of 41 inflammatory analytes were quantified in plasma obtained from 20 severe sepsis patients and 20 age- and sex-matched healthy controls employing an antibody microarray. Two CMs were prepared to mimic severe sepsis (SSCM) and control (CCM), and these CMs were then used for PMN and hCMEC/D3 stimulation in vitro. PMN adhesion to hCMEC/D3 was assessed under conditions of flow (shear stress 0.7 dyn/cm(2)).
  
  
  RESULTS
  Eight inflammatory analytes elevated in plasma obtained from severe sepsis patients were used to prepare SSCM and CCM. Stimulation of PMN with SSCM led to a marked increase in PMN adhesion to hCMEC/D3, as compared to CCM. PMN adhesion was abolished with neutralizing antibodies to either β2 (CD18), αL/β2 (CD11α/CD18; LFA-1) or αM/β2 (CD11β/CD18; Mac-1) integrins. In addition, immune-neutralization of the endothelial (hCMEC/D3) cell adhesion molecule, ICAM-1 (CD54) also suppressed PMN adhesion.
  
  
  CONCLUSIONS
  Human SSCM up-regulates PMN pro-adhesive phenotype and promotes PMN adhesion to cerebrovascular endothelial cells through a β2-integrin-ICAM-1-dependent mechanism. PMN adhesion to the brain microvasculature may contribute to SAE.
authors.affiliation: Department of Physiology and Pharmacology, Western University, 1151 Richmond Str. North, London, ON, N6A 5C1, Canada. christopher.blom@mail.utoronto.ca.
authors.forename: Chris
authors.initials: C
authors.lastname: Blom
authors.affiliation: Department of Physiology and Pharmacology, Western University, 1151 Richmond Str. North, London, ON, N6A 5C1, Canada. bdeller2@uwo.ca.
authors.forename: Brittany L
authors.initials: BL
authors.lastname: Deller
authors.affiliation: Department of Physiology and Pharmacology, Western University, 1151 Richmond Str. North, London, ON, N6A 5C1, Canada. douglas.fraser@lhsc.on.ca.|Children's Health Research Institute, 800 Commissioners Road East, London, ON, N6C 2V5, Canada. douglas.fraser@lhsc.on.ca.|Centre for Critical Illness Research, Lawson Health Research Institute, 800 Commissioners Rd East, London, ON, N6C 6B5, Canada. douglas.fraser@lhsc.on.ca.|Department of Paediatrics, Western University, 100 Collip Circle, London, ON, N6G 4X8, Canada. douglas.fraser@lhsc.on.ca.|Department of Clinical Neurological Sciences, Western University, 339 Windermere Road, London, ON, N6A 5A5, Canada. douglas.fraser@lhsc.on.ca.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Fraser
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, 800 Commissioners Rd East, London, ON, N6C 6B5, Canada. eric.patterson@lhsc.on.ca.
authors.forename: Eric K
authors.initials: EK
authors.lastname: Patterson
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, 800 Commissioners Rd East, London, ON, N6C 6B5, Canada. cmartin1@uwo.ca.|Department of Medicine, Western University, 1151 Richmond Str. North, London, ON, N6A 3K6, Canada. cmartin1@uwo.ca.
authors.forename: Claudio M
authors.initials: CM
authors.lastname: Martin
authors.affiliation: Department of Clinical Neurological Sciences, Western University, 339 Windermere Road, London, ON, N6A 5A5, Canada. bryan.young@lhsc.on.ca.
authors.forename: Bryan
authors.initials: B
authors.lastname: Young
authors.affiliation: Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4K1, Canada. patricia.liaw@taari.ca.|The Thrombosis and Atherosclerosis Research Institute, 237 Barton Str. East, Hamilton, ON, L8L 2X2, Canada. patricia.liaw@taari.ca.
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Liaw
authors.affiliation: Department of Physiology and Pharmacology, Western University, 1151 Richmond Str. North, London, ON, N6A 5C1, Canada. pashoori@gmail.com.
authors.forename: Payam
authors.initials: P
authors.lastname: Yazdan-Ashoori
authors.affiliation: Children's Health Research Institute, 800 Commissioners Road East, London, ON, N6C 2V5, Canada. angelica@angelicaortiz.ca.
authors.forename: Angelica
authors.initials: A
authors.lastname: Ortiz
authors.affiliation: Thermo Fisher Scientific, 3747 N Meridian Rd, Rockford, IL, 61105, USA. brian.webb@thermofisher.com.
authors.forename: Brian
authors.initials: B
authors.lastname: Webb
authors.affiliation: Thermo Fisher Scientific, 3747 N Meridian Rd, Rockford, IL, 61105, USA. greg.kilmer@thermofisher.com.
authors.forename: Greg
authors.initials: G
authors.lastname: Kilmer
authors.affiliation: London Regional Genomics Centre, Robarts Research Institute, 1151 Richmond Str. North, London, ON, N6A 5B7, Canada. dcarter@robarts.ca.
authors.forename: David E
authors.initials: DE
authors.lastname: Carter
authors.affiliation: Centre for Critical Illness Research, Lawson Health Research Institute, 800 Commissioners Rd East, London, ON, N6C 6B5, Canada. gcepinsk@uwo.ca.|Department of Medical Biophysics, Western University, 1151 Richmond Str. North, London, ON, N6A 5C1, Canada. gcepinsk@uwo.ca.
authors.forename: Gediminas
authors.initials: G
authors.lastname: Cepinskas
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001812:Blood-Brain Barrier / Q000378:metabolism; D018821:CD18 Antigens / Q000378:metabolism*; D002448:Cell Adhesion; D002560:Cerebrovascular Circulation; D016207:Cytokines / Q000378:metabolism*; D042783:Endothelial Cells / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology*; D065166:Sepsis-Associated Encephalopathy / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D018821:CD18 Antigens; D016207:Cytokines; D018799:Intercellular Adhesion Molecule-1