Conjugation, immunoreactivity, and immunogenicity of calix[4]arenes; model study to potential calix[4]arene-based Ac3+ chelators.
For the development of calix[4]arene-based radiotherapeutic agents, the conjugation to biomolecules and immunogenicity in mice of potential 225Ac3+-chelating calix[4]arenes were studied. A calix[4]arene triethyl ester isothiocyanate and a bis(calix[4]arene) hexacarboxylic acid, containing a masked thiol functionality, were used in conjugation experiments to a mouse monoclonal antibody and serum albumins. All characterization techniques indicate that only the calix[4]arene carboxylic acid is successfully conjugated to the biomolecules. The immunoreactivity of the conjugates is not impaired when up to 6 equiv of calixarene are bound to the monoclonal antibody. Animal tests indicated that the immunogenicity toward the calix[4]arene is strongly influenced by the nature of the carrier, the dosage, and the injection method. No immune response occurred when a homologous carrier was used or when a heterologous carrier was applied at a dosage of 10 microg per immunization via intravenous injection. Under all other conditions, the presence of antibodies directed against the calix[4]arene was demonstrated. Thus, for the application in radioimmunotherapy, the conjugation of a calix[4]arene to a humanized antibody will probably not lead to an immune response, and the immunoreactivity will not be disturbed.
Department of Supramolecular Chemistry and Technology, MESA+ Research Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
M H
MH
Grote Gansey
A S
AS
de Haan
E S
ES
Bos
W
W
Verboom
D N
DN
Reinhoudt
D000186:Actinium / Q000737:chemistry*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D000917:Antibody Formation / Q000187:drug effects; D047250:Calixarenes; D002614:Chelating Agents / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D018796:Immunoconjugates / Q000737:chemistry* / Q000276:immunology; D017879:Isothiocyanates / Q000737:chemistry; D051379:Mice; D008956:Models, Chemical; D010636:Phenols / Q000737:chemistry* / Q000276:immunology; D012709:Serum Albumin / Q000737:chemistry / Q000276:immunology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000911:Antibodies, Monoclonal; D002614:Chelating Agents; D018796:Immunoconjugates; D017879:Isothiocyanates; D010636:Phenols; D012709:Serum Albumin; C121325:calix(4)arene; D047250:Calixarenes; D000186:Actinium