T-cell immunotherapy for human MK-1-expressing tumors using a fusion protein of the superantigen SEA and anti-MK-1 scFv antibody.
BACKGROUND
The bacterial superantigen staphylococcal enterotoxin A (SEA) is an extremely potent activator of T lymphocytes when presented on major histocompatibility complex (MHC) class II molecules. To develop a tumor-specific superantigen for cancer therapy, we constructed a recombinant fusion protein of SEA and the single-chain variable fragment (scFv) of the FU-MK-1 antibody, which recognizes a glycoprotein antigen (termed MK-1 antigen) present on most carcinomas.


METHODS
We employed recombinant DNA techniques to fuse recombinant mutant SEA to an scFv antibody derived from FU-MK-1 and the resulting fusion protein (SEA/FUscFv) was produced by a bacterial expression system, purified with a metal-affinity column, and characterized for its MK-1-binding specificity and its antitumor activity.


RESULTS
The SEA/FUscFv fusion protein retained the reactivity with MK-1-expressing tumor cells, introduced a specific cytotoxicity of lymphokine-activated killer T-cells to the tumor cells, and consequently suppressed the tumor growth in a SCID mouse xenograft model.


CONCLUSIONS
This genetically engineered SEA/FUscFv fusion protein may serve as a potentially useful immunotherapeutic reagent for human MK-1-expressing tumors.
Ueno
Aruto
A
Department of Biochemistry, Fukuoka University School of Medicine, Japan.
Arakawa
Fumiko
F
Abe
Hironori
H
Matsumoto
Hisanobu
H
Kudo
Toshio
T
Asano
Ryutaro
R
Tsumoto
Kohei
K
Kumagai
Izumi
I
Kuroki
Motomu
M
Kuroki
Masahide
M
D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D015815:Cell Adhesion Molecules / Q000276:immunology* / Q000378:metabolism / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D004768:Enterotoxins / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D000071858:Epithelial Cell Adhesion Molecule; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000276:immunology; D007167:Immunotherapy / Q000379:methods; D000922:Immunotoxins / Q000235:genetics / Q000276:immunology; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D016513:Mice, SCID; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000494:pharmacology; D013274:Stomach Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000628:therapy; D018089:Superantigens / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D004768:Enterotoxins; D000071858:Epithelial Cell Adhesion Molecule; D007128:Immunoglobulin Fragments; D000922:Immunotoxins; D011993:Recombinant Fusion Proteins; D018089:Superantigens; C026066:enterotoxin A, Staphylococcal