Mucosal tolerance to brain antigens preserves endogenous TGFβ-1 and improves neurological outcomes following experimental craniotomy

Acta Neurochir Suppl. 2011:111:283-7. doi: 10.1007/978-3-7091-0693-8_47.

Abstract

Intracranial surgery causes brain damage from cortical incisions, intraoperative hemorrhage, retraction, and electrocautery; collectively these injuries have recently been coined surgical brain injury (SBI). Inflammation following SBI contributes to neuronal damage. This study develops T-cells that are immunologically tolerant to brain antigen via the exposure of myelin basic protein (MBP) to airway mucosa. We hypothesize that these T-cells will migrate to the site of corticotomy, secrete immunosuppressive cytokines, such as TGFβ1, reduce inflammation, and improve neurological outcomes following SBI. A standard model for SBI was used for this experiment. C57 mice were divided into six groups: SHAM+Vehicle, SHAM+Ovalbumin, SHAM+MBP, SBI+Vehicle, SBI+OVA, and SBI+MBP. Induction of mucosal tolerance to vehicle, ovalbumin, or MBP was performed prior to SBI. Neurological scores and TBFβ1 cytokine levels were measured 48 h postoperatively. Mice receiving craniotomy demonstrated a reduction in neurological score. Animals tolerized to MBP (SBI+MBP) had better postoperative neurological scores than SBI+Vehicle and SBI+OVA. SBI inhibited the cerebral expression TGFβ1 in PBS and OVA treated groups, whereas MBP treated-animals preserved preoperative levels. Mucosal tolerance to MBP leads to significant improvement in neurological outcome that is associated with the preservation of endogenous levels of brain TGFβ1.

MeSH terms

  • Analysis of Variance
  • Animals
  • Brain / immunology
  • Brain / metabolism
  • Brain / pathology
  • Brain Injuries / complications
  • Brain Injuries / etiology*
  • Brain Injuries / pathology*
  • Brain Injuries / therapy
  • Craniotomy / adverse effects*
  • Disease Models, Animal
  • Drug Tolerance / immunology
  • Inflammation / etiology
  • Mice
  • Mice, Inbred C57BL
  • Mucous Membrane / drug effects
  • Mucous Membrane / immunology*
  • Myelin Basic Protein / immunology
  • Neurologic Examination
  • Ovalbumin / therapeutic use
  • Transforming Growth Factor beta1 / immunology
  • Transforming Growth Factor beta1 / metabolism*
  • Treatment Outcome

Substances

  • Myelin Basic Protein
  • Transforming Growth Factor beta1
  • Ovalbumin