IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by McGuinness, C. R.
Right arrow Articles by Mantis, N. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by McGuinness, C. R.
Right arrow Articles by Mantis, N. J.

 Previous Article  |  Next Article 

Infection and Immunity, June 2006, p. 3463-3470, Vol. 74, No. 6
0019-9567/06/$08.00+0     doi:10.1128/IAI.00324-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.

Characterization of a Novel High-Affinity Monoclonal Immunoglobulin G Antibody against the Ricin B Subunit

Carolyn R. McGuinness and Nicholas J. Mantis*

Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York 12208

Received 27 February 2006/ Returned for modification 26 March 2006/ Accepted 1 April 2006

There is an urgent need for the development of a passive immunotherapy against the category B select agent ricin, a lethal ribosome-inactivating toxin composed of an enzymatic A subunit (RTA) and a single binding B subunit (RTB). To date, only one monoclonal antibody (MAb), a mouse immunoglobulin G (IgG1) against RTA called R70, has been deemed sufficiently potent in animal models to warrant further testing in humans. In this study, we have identified and characterized MAb 24B11, a murine IgG1 directed against RTB. In a Vero cell cytotoxicity assay, 24B11 was approximately two times more effective at neutralizing ricin than was R70. The equilibrium dissociation constants of 24B11 (KD = 4.2 x 10–9 M) and R70 (KD = 3.2 x 10–9 M) were virtually identical, suggesting that the difference in neutralization activity between the two MAbs was not due to differing affinities for the toxin. 24B11 blocked ricin attachment to galactoside receptors on primary mouse splenocytes and on the apical surfaces of human mucosal epithelial cell monolayers. Surprisingly, R70 also effectively interfered with ricin attachment to receptors on cell surfaces. Using a phage-displayed peptide library, we determined that 24B11 binds an epitope on RTB adjacent to, but not within, one of the two galactose binding domains. Finally, we demonstrate that R70 and 24B11, when combined, function synergistically to neutralize ricin in vitro, raising the possibility that these two MAbs could serve as a novel immunotherapeutic in vivo.

* Corresponding author. Mailing address: Division of Infectious Disease, Wadsworth Center, 120 New Scotland Avenue, Albany, NY 12208. Phone: (518) 402-2750. Fax: (518) 402-4773. E-mail: nmantis{at}wadsworth.org.

Editor: J. T. Barbieri

Infection and Immunity, June 2006, p. 3463-3470, Vol. 74, No. 6
0019-9567/06/$08.00+0     doi:10.1128/IAI.00324-06
Copyright © 2006, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2006 by the American Society for Microbiology. All rights reserved.