A novel vascular targeting strategy for brain-derived endothelial cells using a TCR mimic antibody. Academic Article uri icon

Overview

abstract

  • Organ-specific vascular targeting, for example, to the blood-brain barrier, requires the identification of unique molecular addresses on a subset of endothelial cells. The present study describes a crucial step towards tapping the exquisite specificity of the peptide/HLA class I system for this goal. We utilized a novel T-cell receptor (TCR) mimic antibody of high affinity and specificity, which is restricted by HLA-A2 and has been generated to recognize a peptide epitope derived from p68 RNA helicase (YLLPAIVHI). The parent protein is highly expressed by brain endothelial cells. Flow cytometry and confocal imaging showed that the antibody binds to HLA-A2-positive human brain-derived endothelial cells, both immortalized hCMEC/D3 cells and primary cells. The TCR mimic antibody undergoes internalization into vesicles, where significant colocalization occurs with the early endosomal marker EEA-1, but barely with caveolin-1. To our knowledge internalization of neither MHC class I protein nor TCR mimics by brain endothelial cells has been previously observed. Knock down of p68 protein expression by siRNA reduced the presentation of YLLPAIVHI-peptide/HLA-A2 complexes on the cell membrane by half as measured by flow cytometry 48 h later. We also found that brain endothelial cells isolated from HLA-A2 transgenic mouse strains express the A2 transgene, and brain endothelial cells of one of these strains also present YLLPAIVHI-peptide/HLA-A2, making these mouse strains suitable models for studying TCR mimic antibodies in vivo. In conclusion, these data strongly support the notion that TCR mimic antibodies could be a new class of therapeutic targeting agents in a wide variety of diseases.

publication date

  • November 1, 2010

Research

keywords

  • Antibodies, Monoclonal
  • Blood-Brain Barrier
  • Brain
  • DEAD-box RNA Helicases
  • Endothelial Cells
  • HLA-A2 Antigen
  • Immunomagnetic Separation
  • Receptors, Antigen, T-Cell

Identity

PubMed Central ID

  • PMC2939940

Scopus Document Identifier

  • 77957830071

Digital Object Identifier (DOI)

  • 10.1002/jcp.22256

PubMed ID

  • 20506235

Additional Document Info

volume

  • 225

issue

  • 3