Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.

A humanised IgG1/k version of A33 (hA33) has been constructed and expressed with yields up to 700 mg l-1 in mouse myeloma NS0 cells in suspension culture. The equilibrium dissociation constant of hA33 (KD = 1.3 nM) was shown to be equivalent to that of the murine antibody in a cell-binding assay. hA...

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Main Authors:	King, D. J., Antoniw, P., Owens, R. J., Adair, J. R., Haines, A. M., Farnsworth, A. P., Finney, H., Lawson, A. D., Lyons, A., Baker, T. S.
Format:	Online
Language:	English
Published:	1995
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2034099/

id	pubmed-2034099
recordtype	oai_dc
spelling	pubmed-20340992009-09-10 Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy. King, D. J. Antoniw, P. Owens, R. J. Adair, J. R. Haines, A. M. Farnsworth, A. P. Finney, H. Lawson, A. D. Lyons, A. Baker, T. S. Research Article A humanised IgG1/k version of A33 (hA33) has been constructed and expressed with yields up to 700 mg l-1 in mouse myeloma NS0 cells in suspension culture. The equilibrium dissociation constant of hA33 (KD = 1.3 nM) was shown to be equivalent to that of the murine antibody in a cell-binding assay. hA33 labelled with yttrium-90 using the macrocyclic chelator 12N4 (DOTA) was shown to localise very effectively to human colon tumour xenografts in nude mice, with tumour levels increasing as blood concentration fell up to 144 h. A Fab' variant of hA33 with a single hinge thiol group to facilitate chemical cross-linking has also been constructed and expressed with yields of 500 mg l-1. Trimaleimide cross-linkers have been used to produce a trivalent Fab fragment (hA33 TFM) that binds antigen on tumour cells with greater avidity than hA33 IgG. Cross-linkers incorporating 12N4 or 9N3 macrocycles have been used to produce hA33 TFM labelled stably and site specifically with yttrium-90 or indium-111 respectively. These molecules have been used to demonstrate that hA33 TFM is cleared more rapidly than hA33 IgG from the circulation of animals but does not lead to accumulation of these metallic radionuclides in the kidney. 90Y-labelled hA33 TFM therefore appears to be the optimal form of the antibody for radioimmunotherapy of colorectal carcinoma. 1995-12 /pmc/articles/PMC2034099/ /pubmed/8519646 Text en
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	King, D. J. Antoniw, P. Owens, R. J. Adair, J. R. Haines, A. M. Farnsworth, A. P. Finney, H. Lawson, A. D. Lyons, A. Baker, T. S.
spellingShingle	King, D. J. Antoniw, P. Owens, R. J. Adair, J. R. Haines, A. M. Farnsworth, A. P. Finney, H. Lawson, A. D. Lyons, A. Baker, T. S. Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.
author_facet	King, D. J. Antoniw, P. Owens, R. J. Adair, J. R. Haines, A. M. Farnsworth, A. P. Finney, H. Lawson, A. D. Lyons, A. Baker, T. S.
author_sort	King, D. J.
title	Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.
title_short	Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.
title_full	Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.
title_fullStr	Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.
title_full_unstemmed	Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.
title_sort	preparation and preclinical evaluation of humanised a33 immunoconjugates for radioimmunotherapy.
description	A humanised IgG1/k version of A33 (hA33) has been constructed and expressed with yields up to 700 mg l-1 in mouse myeloma NS0 cells in suspension culture. The equilibrium dissociation constant of hA33 (KD = 1.3 nM) was shown to be equivalent to that of the murine antibody in a cell-binding assay. hA33 labelled with yttrium-90 using the macrocyclic chelator 12N4 (DOTA) was shown to localise very effectively to human colon tumour xenografts in nude mice, with tumour levels increasing as blood concentration fell up to 144 h. A Fab' variant of hA33 with a single hinge thiol group to facilitate chemical cross-linking has also been constructed and expressed with yields of 500 mg l-1. Trimaleimide cross-linkers have been used to produce a trivalent Fab fragment (hA33 TFM) that binds antigen on tumour cells with greater avidity than hA33 IgG. Cross-linkers incorporating 12N4 or 9N3 macrocycles have been used to produce hA33 TFM labelled stably and site specifically with yttrium-90 or indium-111 respectively. These molecules have been used to demonstrate that hA33 TFM is cleared more rapidly than hA33 IgG from the circulation of animals but does not lead to accumulation of these metallic radionuclides in the kidney. 90Y-labelled hA33 TFM therefore appears to be the optimal form of the antibody for radioimmunotherapy of colorectal carcinoma.
publishDate	1995
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2034099/
_version_	1611405242479411200

Preparation and preclinical evaluation of humanised A33 immunoconjugates for radioimmunotherapy.

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