title: Conjugation of quantum dots and JT95 IgM monoclonal antibody for thyroid carcinoma without abolishing the specificity and activity of the antibody.
abstract: Among the immunoglobulins, IgM class-antibodies are now considered to be potent immunological reagents for anticancer remedies. However, only a few reports are available about the effective labeling of IgM with enzymes, fluorescence, or other bioreactive reagents. Here, we report an effective application of luminescent semiconductive nanoparticles, quantum dots (QDs), as a labeling material of the IgM antibody. The CdSe carboxyl QDs were reacted with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysulfo- succinimide in 2-(morpholino) ethanesulfonic acid. The reacted QDs were then coupled to JT95 IgM antibody, which recognizes thyroid carcinoma associated antigen. The specificity and activity of the conjugates were tested by immunoblot, immunoquantitive assay and immunohistological imaging. The QDs were firmly conjugated with JT95 IgM monoclonal antibody. In immunoblot assay, QD-JT95 conjugates directly detected the target molecules without obstructing the binding site. In immunoquantitive assay, the conjugates could quantify the antigen in the range of 1.56-100 μg/mL. Also, QDs-labeled antibody detected the antigen on plasma membrane. Our results demonstrate that labeling of JT95 and other IgM class antibodies with QDs is feasible. This approach may be an important method for the medical application of IgM in the diagnosis and treatment of cancers.
authors.affiliation: Department of Molecular Cell Biology, Institute of DNA Medicine, Research Center for Medical Sciences, Minato-ku, Tokyo 105-8461, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Watanabe
authors.forename: Kouki
authors.initials: K
authors.lastname: Fujioka
authors.forename: Nobutake
authors.initials: N
authors.lastname: Akiyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takeyama
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Manabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Manome
mesh_terms: D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000276:immunology*; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology / Q000378:metabolism*; D019187:Cadmium Compounds / Q000032:analysis*; D045744:Cell Line, Tumor; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis / Q000276:immunology; D045663:Quantum Dots; D018036:Selenium Compounds / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013964:Thyroid Neoplasms / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D019187:Cadmium Compounds; D007075:Immunoglobulin M; C115435:JT95 monoclonal antibody; D018036:Selenium Compounds; C058667:cadmium selenide