Molecular Cancer Therapeutics CTRC-AACR San Antonio Breast Cancer Symposium Tumor Immunology: New Perspectives
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bera, T. K.
Right arrow Articles by Pastan, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bera, T. K.
Right arrow Articles by Pastan, I.
Vol. 1, 79-84, December 2001     Molecular Cancer Therapeutics
© 2001 American Association for Cancer Research

Bivalent Disulfide-stabilized Fragment Variable Immunotoxin Directed against Mesotheliomas and Ovarian Cancer

Tapan K. Bera, Juanita Williams-Gould, Richard Beers, Partha Chowdhury and Ira Pastan1

Laboratory of Molecular Biology, National Cancer Institute, NIH, Bethesda, Maryland 20892-4255

We have used protein engineering to generate a stable bivalent fragment variable (Fv) molecule from the antimesothelin antibody SS, in which the VH and VL domains of the Fv are linked to each other by a disulfide bond, and the two Fvs are connected by a flexible 15-amino acid (Gly4-Ser)3 linker. The SS (dsFv)2 molecule is fused to a Mr 38,000 truncated form of Pseudomonas exotoxin to generate a bivalent, disulfide stabilized, (dsFv)2 immunotoxin. The immunotoxin was expressed in Escherichia coli, refolded in vitro, and purified to ~95% purity with a high yield of >10%. Binding studies demonstrated that the (dsFv)2 molecule has 40 times higher apparent affinity for recombinant mesothelin than a monovalent dsFv molecule. The (dsFv)2 immunotoxin was 4–10-fold more cytotoxic to three mesothelin antigen-positive cell lines than the monovalent dsFv immunotoxin. However, when tested in mice bearing tumor cells expressing mesothelin, the antitumor activity of the bivalent immunotoxin is very similar to the activity of the lower affinity monovalent immunotoxin. Our data indicate that increasing affinity of an antibody fragment does not necessarily lead to higher antitumor activity of an immunotoxin in vivo.




This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
Y. Zhang, L. Xiang, R. Hassan, and I. Pastan
Immunotoxin and Taxol synergy results from a decrease in shed mesothelin levels in the extracellular space of tumors
PNAS, October 23, 2007; 104(43): 17099 - 17104.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Cancer Research Clinical Cancer Research
Cancer Epidemiology Biomarkers & Prevention Molecular Cancer Therapeutics
Molecular Cancer Research Cancer Prevention Research
Cancer Prevention Journals Portal Cancer Reviews Online
Annual Meeting Education Book Meeting Abstracts Online
Copyright © 2001 by the American Association for Cancer Research.