Modulation of Epstein-Barr virus latent membrane protein 1 activity by intrabodies.
OBJECTIVE
The Epstein-Barr virus (EBV) has been implicated in the development of many human neoplasias including B lymphoma and nasopharyngeal carcinoma. EBV latent membrane protein 1 (LMP1) is essential to virus-induced B cell immortalization and the downregulation of cell adhesion molecules that increases cell motility. Therefore, identifying LMP1 activity modulation methods may lead to the development of new therapies for LMP1-positive tumors.


METHODS
This study uses a phage display single-chain variable fragments (scFvs) library to screen recombinant antibodies specific to the LMP1 C terminal region. A total of 45 individual clones were obtained, and these scFvs were cloned as intrabodies and transfected into LMP1-positive cells.


RESULTS
One of the scFv clones, designated H3, was capable of reducing LMP1-mediated NF-kappaB activation in HEK293 cells. Immunofluorescence and co-immunoprecipitation studies show that scFv H3 could interact with LMP1 in vivo. In addition, expression of scFv H3 intrabody could reduce cell motility in MDCK-LMP1 cells in the transwell migration assay.


CONCLUSIONS
These data indicate that scFv H3 intrabody can inhibit LMP1 functions in epithelial cells and may be useful for attenuating the LMP1 function in LMP1-positive tumors.
Fang
Chih Yeu
CY
Institute of Molecular Medicine, National Tsing Hua University, Hsin-Chu, Taiwan, ROC.
Chiang
Chen Yi
CY
Pan
Yun Ru
YR
Tse
Ka Po
KP
Chang
Yu Sun
YS
Chang
Hwan You
HY
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000918:Antibody Specificity; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000276:immunology; D004285:Dogs; D004847:Epithelial Cells; D004854:Herpesvirus 4, Human / Q000472:pathogenicity*; D006801:Humans; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D019151:Peptide Library; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D017422:Sequence Analysis, DNA; D014162:Transfection; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000276:immunology*
D000914:Antibodies, Viral; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D007135:Immunoglobulin Variable Region; D019151:Peptide Library; D011994:Recombinant Proteins; D014763:Viral Matrix Proteins