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A novel vascular targeting strategy for brain‐derived endothelial cells using a TCR mimic antibody
Author(s) -
Bhattacharya Raktima,
Xu Yan,
Rahman Md. Ashequr,
Couraud PierreOlivier,
Romero Ignacio A.,
Weksler Babette B.,
Weidanz Jon A.,
Bickel Ulrich
Publication year - 2010
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.22256
Subject(s) - t cell receptor , biology , internalization , antibody , microbiology and biotechnology , flow cytometry , epitope , major histocompatibility complex , antigen , t cell , receptor , immune system , immunology , biochemistry
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. J. Cell. Physiol. 225: 664–672, 2010. © 2010 Wiley‐Liss, Inc.