Abstract |
The development of human antibodies specific for certain B cell markers is required to generate therapeutic antibody leads with improved therapeutic indices against B-cell lymphomas. To meet this demand, we selected a primary human antibody library, HuDVFab-8L, against human B lymphoblastic IM-9 cells via a 'Biopanning and Rapid Analysis of Selective Interactive Ligands (BRASIL)' cell panning approach. Six Fab clones that specifically bound to IM-9 cells were successfully isolated. Among these clones, two clones (IM-L6-E and IM-L8-G), were found to be specific for CD23 (FcɛRII). Affinity maturation of these Fab clones was then performed in a hierarchical manner by constructing secondary antibody libraries through combining heavy (H) chains of two Fabs with the human kappa L chain sublibrary HuNL-D3 followed by biopanning against the CD23 antigen. Clone IM-L6-5, one of the affinity maturated Fab derivatives from IM-L6-E, has a binding affinity of k(D)≈30 nM to soluble CD23. In addition, IM-L6-5 Fab is able to bind to an inducible form of CD23 expressed on U937 cells upon IL-4 stimulation, and inhibits binding of human IgE to CD23. Since the Fab IM-L6-5 is derived from a fully human naïve origin, we believe that IM-L6-5 can be utilized for the development of a therapeutic mAb which may have an improved therapeutic index over lumiliximab, a primatized anti-CD23 mAb, for the treatment of CLL or allergic diseases.
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Authors | Hyo-jung Choi, Suk-yoon Song, Jae-bong Yoon, Li-kun Liu, Kristine Kim, Sang-hoon Cha |
Journal | Immunology letters
(Immunol Lett)
Vol. 136
Issue 2
Pg. 213-20
(May 2011)
ISSN: 1879-0542 [Electronic] Netherlands |
PMID | 21277901
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2011 Elsevier B.V. All rights reserved. |
Chemical References |
- Immunoglobulin Fab Fragments
- Immunoglobulin Light Chains
- Peptide Library
- Receptors, IgE
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Topics |
- Antibody Affinity
(immunology)
- Antibody Specificity
(immunology)
- Cell Line, Tumor
- Humans
- Immunoglobulin Fab Fragments
(immunology, isolation & purification)
- Immunoglobulin Light Chains
(immunology, metabolism)
- Lymphoma, B-Cell
(metabolism)
- Peptide Library
- Protein Binding
(immunology)
- Receptors, IgE
(immunology, metabolism)
- U937 Cells
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