Targeting of LAK activity to CEA-expressing tumor cells with an anti-CEA scFv/IL-2 fusion protein.
BACKGROUND
Fusion of tumor-specific monoclonal antibody (MAb) and cytokines has proved to be an efficient way to target cytokines to tumor cells and hence focuses the killing activity of effector cells to the target cells. We previously produced a high affinity MAb, F11-39, against carcinoembryonic antigen (CEA), which is often overexpressed on the surface of various tumor cells.


METHODS
To target the cytotoxicity of effector cells to CEA-expressing tumor cells, we employed recombinant DNA techniques to fuse recombinant human interleukin-2 (rhIL-2) to a single chain variable fragment (scFv) antibody derived from F11-39. The resulting fusion protein, designated F39scFv/IL-2, was expressed in the Sp2/0-Ag14 mouse hybridoma cells, purified by CEA-affinity chromatography and characterized for the CEA-binding specificity and the IL-2 biological activity.


RESULTS
F39scFv/IL-2 protein effectively targeted rhIL-2 onto the surface of CEA-expressing tumor cells and consequently introduced a specific cytotoxicity of lymphokine-activated killer cells to the tumor cells.


CONCLUSIONS
This approach may be used for in vivo administration to localize IL-2 to tumor tissues, maximizing the immune response to CEA-expressing tumors while keeping systemic side effects to a minimum.
Liao
S
S
First Department of Biochemistry, School of Medicine, Fukuoka University, Japan.
Khare
P D
PD
Arakawa
F
F
Kuroki
M
M
Hirose
Y
Y
Fujimura
S
S
Tomita
Y
Y
Kuroki
M
M
D000818:Animals; D015153:Blotting, Western; D002272:Carcinoembryonic Antigen / Q000096:biosynthesis* / Q000276:immunology*; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006801:Humans; D006825:Hybridomas / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007128:Immunoglobulin Fragments / Q000378:metabolism*; D007376:Interleukin-2 / Q000378:metabolism*; D051379:Mice; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured
D002272:Carcinoembryonic Antigen; D018076:DNA, Complementary; D007128:Immunoglobulin Fragments; D007376:Interleukin-2; D011993:Recombinant Fusion Proteins