Heterobifunctional reagents: A new approach to radiolabeling of monoclonal antibodies
The use of bifunctional chelate such as the cyclic anhydride of DTPA for radiolabeling antibodies (Abs) may lead to homopolymerization, and intra- or intermolecular cross-linking, with resulting denaturation and decrease immunoreactivity of Abs. The authors, therefore, investigated the use of heterobifunctional reagents, whereby one group selectively couples to the amino group of the Ab and the other group to the radiometal for Ab labeling. One such reagent, 2,6-Dioxo-N-(carboxymethyl)morphine (DCM) was synthesized by reacting nitrilotriacetic acid with acetic anhydride. The other agent tested was commercially available N-Succinimidyl-3-(2-pyridyldithio) propionate (SPDP). These agents were evaluated independently for their ability to label a monoclonal antibody (MoAb) to a melanoma associated antigen (Ag). Labeling proceeded at a 2mg/ml concentration of the Ab, at HEPES pH 8.2, and 7.0, respectively, at room temperature for 30 min. The conjugate subsequently was labeled with Tc-99m or In-111. For comparison, the same labeled Abs also were prepared by using the cyclic anhydride of DTPA. Binding of the Ab to melanoma cells and control cells then was assayed. The results of cell binding experiments (N=3 per agent) in the region of Ag excess (X+-SD) were as follows: 62.6 +- 2.83% for Tc-99m-DCM-MoAb and 41.3+-1.84% for Tc-99m-SPDP-MoAb vs. 28.6 +- 1.16% for Tc-99m-DTPA-MoAb (p<0.01); 56.2 +- 2.97% for In-111-DCM-MoAb vs. 28.6 +- 1.16% for In-111-DTPA-M0Ab. Binding of all agents to the control lymphoid cell line was less than 3%. These results suggest that heterobifunctional reagents can reduce the loss of immunoreactivity of labeled MoAbs.
- Research Organization:
- Columbia Univ., New York, NY
- OSTI ID:
- 6852543
- Report Number(s):
- CONF-850611-; TRN: 87-011057
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 26:5; Conference: 32. annual meeting of the Society of Nuclear Medicine, Houston, TX, USA, 2 Jun 1985
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DTPA
CHEMICAL REACTION KINETICS
LABELLING
MELANOMAS
RADIOIMMUNOTHERAPY
MONOCLONAL ANTIBODIES
RADIOPHARMACEUTICALS
CHEMICAL PREPARATION
EVALUATION
ANTIGEN-ANTIBODY REACTIONS
ANTIGENS
CHELATING AGENTS
MOLECULAR BIOLOGY
PERFORMANCE TESTING
POLYMERIZATION
RADIOIMMUNOLOGY
TECHNETIUM 99
TRACER TECHNIQUES
AMINO ACIDS
ANTIBODIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DISEASES
DRUGS
HOURS LIVING RADIOISOTOPES
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
MEDICINE
NEOPLASMS
NUCLEAR MEDICINE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
RADIOISOTOPES
RADIOLOGY
RADIOPROTECTIVE SUBSTANCES
RADIOTHERAPY
REACTION KINETICS
SYNTHESIS
TECHNETIUM ISOTOPES
TESTING
THERAPY
YEARS LIVING RADIOISOTOPES
550604* - Medicine- Unsealed Radionuclides in Therapy- (1980-)