title: A novel recombinant antibody specific to full-length stromal derived factor-1 for potential application in biomarker studies.
abstract: BACKGROUND
  Stromal derived factor-1α (SDF-1α/CXCL12) is a chemokine that is up-regulated in diseases characterised by tissue hypoxia, including myocardial infarction, ischaemic cardiomyopathy and remote ischaemic conditioning (RIC), a technique of cyclical, non-injurious ischaemia applied remote from the heart that protects the heat from lethal ischaemia-reperfusion injury. Accordingly, there is considerable interest in SDF-1α as a potential biomarker of such conditions. However, SDF-1α is rapidly degraded and inactivated by dipeptidyl peptidase 4 and other peptidases, and the kinetics of intact SDF-1α remain unknown.
  
  
  RESULTS
  To facilitate investigation of full-length SDF-1α we established an ELISA using a novel recombinant human antibody we developed called HCI.SDF1. HCI.SDF1 is specific to the N-terminal sequence of all isoforms of SDF-1 and has a comparable KD to commercially available antibodies. Together with a detection antibody specific to the α-isoform, HCI.SDF1 was used to specifically quantify full-length SDF-1α in blood for the first time. Using RIC applied to the hind limb of Sprague-Dawley rats or the arms of healthy human volunteers, we demonstrate an increase in SDF-1α using a commercially available antibody, as previously reported, but an unexpected decrease in full-length SDF-1α after RIC in both species.
  
  
  CONCLUSIONS
  We report for the first time the development of a novel recombinant antibody specific to full-length SDF-1. Applied to RIC, we demonstrate a significant decrease in SDF-1α that is at odds with the literature and suggests a need to investigate the kinetics of full-length SDF-1α in conditions characterised by tissue hypoxia.
authors.affiliation: The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
authors.forename: Daniel I
authors.initials: DI
authors.lastname: Bromage
authors.affiliation: The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
authors.forename: Stasa
authors.initials: S
authors.lastname: Taferner
authors.affiliation: The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Pillai
authors.affiliation: The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
authors.forename: Derek M
authors.initials: DM
authors.lastname: Yellon
authors.affiliation: The Hatter Cardiovascular Institute, University College London, London, United Kingdom.
authors.forename: Sean M
authors.identifier: http://orcid.org/0000-0001-5182-4980
authors.initials: SM
authors.lastname: Davidson
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D015153:Blotting, Western; D054377:Chemokine CXCL12 / Q000097:blood / Q000276:immunology*; D018819:Dipeptidyl Peptidase 4 / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D000860:Hypoxia / Q000097:blood / Q000175:diagnosis / Q000378:metabolism; D007511:Ischemia / Q000097:blood / Q000175:diagnosis / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins
chemical_list: D000906:Antibodies; D015415:Biomarkers; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D011994:Recombinant Proteins; C000602659:DPP4 protein, rat; D018819:Dipeptidyl Peptidase 4