title: Phage display for identification of serum biomarkers of traumatic brain injury.
abstract: The extent and severity of traumatic brain injuries (TBIs) can be difficult to determine with current diagnostic methods. To address this, there has been increased interest in developing biomarkers to assist in the diagnosis, determination of injury severity, evaluation of recovery and therapeutic efficacy, and prediction of outcomes. Several promising serum TBI biomarkers have been identified using hypothesis-driven approaches, largely examining proteins that are abundant in neurons and non-neural cells in the CNS.
  
  
  
  An unbiased approach, phage display, was used to identify serum TBI biomarkers. In this proof-of-concept study, mice received a TBI using the controlled cortical impact model of TBI (1mm injury depth, 3.5m/s velocity) and phage display was utilized to identify putative serum biomarkers at 6h postinjury.
  
  
  
  An engineered phage which preferentially bound to injured serum was sequenced to identify the 12-mer 'recognizer' peptide expressed on the coat protein. Following synthesis of the recognizer peptide, pull down, and mass spectrometry analysis, the target protein was identified as glial fibrillary acidic protein (GFAP).
  
  
  
  GFAP has previously been identified as a promising TBI biomarker. The results provide proof of concept regarding the ability of phage display to identify TBI serum biomarkers. This methodology is currently being applied to serum biomarkers of mild TBI.
authors.affiliation: Spinal Cord & Brain Injury Research Center, University of Kentucky, Lexington, KY, USA.
authors.forename: Sarbani
authors.initials: S
authors.lastname: Ghoshal
authors.affiliation: Spinal Cord & Brain Injury Research Center, University of Kentucky, Lexington, KY, USA.
authors.forename: Vimala
authors.initials: V
authors.lastname: Bondada
authors.affiliation: Spinal Cord & Brain Injury Research Center, University of Kentucky, Lexington, KY, USA.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Saatman
authors.affiliation: Department of Gerontology, University of Kentucky, Lexington, KY, USA.
authors.forename: Rodney P
authors.initials: RP
authors.lastname: Guttmann
authors.affiliation: Spinal Cord & Brain Injury Research Center, University of Kentucky, Lexington, KY, USA. Electronic address: jgeddes@uky.edu.
authors.forename: James W
authors.initials: JW
authors.lastname: Geddes
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001435:Bacteriophages / Q000235:genetics / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D001774:Blood Chemical Analysis / Q000379:methods*; D000070642:Brain Injuries, Traumatic / Q000097:blood* / Q000175:diagnosis*; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D061505:Cell Surface Display Techniques; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005904:Glial Fibrillary Acidic Protein / Q000097:blood*; D008297:Male; D008810:Mice, Inbred C57BL; D010296:Parietal Lobe; D019151:Peptide Library
chemical_list: D015415:Biomarkers; D036022:Capsid Proteins; D005904:Glial Fibrillary Acidic Protein; D019151:Peptide Library; C528900:glial fibrillary astrocytic protein, mouse
keywords: Animal models; Biomarkers; Blood; Concussion; Rodents; Traumatic brain injury