Chemical conjugation of a novel antibody-interleukin 2 immunoconjugate against c-erbB-2 product.
OBJECTIVE
To develop a new chemical method to produce a monoclonal antibody (MoAb) 520C9/recombinant human interleukin 2 (rhIL-2) conjugate.


METHODS
MoAb 520C9 reactive with the protooncogene c-erbB-2 product P185 was chemically conjugated with rhIL-2 by using a simple two-step method. First, the rhIL-2 was activated by Sulfosuccinimidyl 4-[N-maleimidomethyl] cyclohexane-1-carboxylate, a heterobifunctional linker, and N-succinimidyl s-acetylthioacetate was introduced onto 520C9. Then SATA on the 520C9 was reacted with the maleimide group on the activated rhIL-2 to generate 520C9-rhIL-2 immunoconjugate.


RESULTS
The immunoconjugate retained the antigen binding activity compared to the respective native antibody as determined by an indirect live cell binding assay. The immunoconjugate also possessed IL-2 activity as measured by the standard CTLL-2 cells proliferation assay and the stimulation of human peripheral blood mononuclear cells (PBMCs) into lymphokine-activated killer cells.


CONCLUSIONS
Our method of conjugation of rhIL-2 to 520C9 preserves the binding activity of the antibody and the cytokine function of IL-2. This simple and efficient method of conjugation should be applicable to other types of MoAbs and recombinant cytokines.
Li
J
J
Department of Radiology, Hamilton Regional Cancer Center, McMaster University Medical Center, Hamilton, Ontario L8N 3Z5, Canada.
Lee
S E
SE
Belciug
M
M
Ring
D B
DB
Kwok
C S
CS
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D018796:Immunoconjugates / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D007376:Interleukin-2 / Q000737:chemistry*; D011485:Protein Binding; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D011994:Recombinant Proteins / Q000737:chemistry; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018796:Immunoconjugates; D007376:Interleukin-2; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins