HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 281, Issue 11, 6985-6992, March 17, 2006

This Article Full Text Full Text (PDF) All Versions of this Article: 281/11/6985    most recent M511165200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yoon, S. O. Articles by Hong, H. J. Search for Related Content PubMed PubMed Citation Articles by Yoon, S. O. Articles by Hong, H. J. Social Bookmarking                      What's this?

Construction, Affinity Maturation, and Biological Characterization of an Anti-tumor-associated Glycoprotein-72 Humanized Antibody^*

Sun Ok Yoon¹, Tae Sup Lee¹, Sang Jick Kim, Myung Hee Jang, Young Jun Kang, Jae Hyun Park, Keun-Soo Kim^¶, Hyun Sil Lee, Chun Jeih Ryu, Noreen R. Gonzales^||, Syed V. S. Kashmiri^||, Sang Moo Lim^**, Chang Woon Choi^**2, and Hyo Jeong Hong³

From the Laboratory of Antibody Engineering, ^¶Aprogen, Inc., Korea Research Institute of Bioscience and Biotechnology, 52 Eoeun-dong, Yuseong-gu, Daejon 305-333, the Laboratory of Cyclotron Application, the ^**Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences, 215-4 Gongneung, Nowon, Seoul 139-706, Korea, and the ^||Laboratory of Tumor Immunology and Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892-1750

The tumor-associated glycoprotein (TAG)-72 is expressed in the majority of human adenocarcinomas but is rarely expressed in most normal tissues, which makes it a potential target for the diagnosis and therapy of a variety of human cancers. Here we describe the construction, affinity maturation, and biological characterization of an anti-TAG-72 humanized antibody with minimum potential immunogenicity. The humanized antibody was constructed by grafting only the specificity-determining residues (SDRs) within the complementarity-determining regions (CDRs) onto homologous human immunoglobulin germ line segments while retaining two mouse heavy chain framework residues that support the conformation of the CDRs. The resulting humanized antibody (AKA) showed only about 2-fold lower affinity compared with the original murine monoclonal antibody CC49 and 27-fold lower reactivity to patient serum compared with the humanized antibody HuCC49 that was constructed by CDR grafting. The affinity of AKA was improved by random mutagenesis of the heavy chain CDR3 (HCDR3). The highest affinity variant (3E8) showed 22-fold higher affinity compared with AKA and retained the original epitope specificity. Mutational analysis of the HCDR3 residues revealed that the replacement of Asn⁹⁷ by isoleucine or valine was critical for the affinity maturation. The 3E8 labeled with ¹²⁵I or ¹³¹I showed efficient tumor targeting or therapeutic effects, respectively, in athymic mice with human colon carcinoma xenografts, suggesting that 3E8 may be beneficial for the diagnosis and therapy of tumors expressing TAG-72.

Received for publication, October 13, 2005 , and in revised form, December 21, 2005.

^* This work was supported by Korea Research Institute of Bioscience and Biotechnology Research Initiative Program Grant KOS0130511, Ministry of Health and Welfare Grant BGM0700511, and Ministry of Science and Technology of Korea Grant TNM0200512 and the National Nuclear Technology Program. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ Both authors contributed equally to this work.

² To whom correspondence may be addressed. Tel.: 82-2-970-1214; Fax: 82-2-970-1341; E-mail: cwchoi{at}kcch.re.kr. ³ To whom correspondence may be addressed. Tel.: 82-42-860-4122; Fax: 82-42-860-4597; E-mail: hjhong{at}kribb.re.kr.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				K. Makabe, T. Nakanishi, K. Tsumoto, Y. Tanaka, H. Kondo, M. Umetsu, Y. Sone, R. Asano, and I. Kumagai Thermodynamic Consequences of Mutations in Vernier Zone Residues of a Humanized Anti-human Epidermal Growth Factor Receptor Murine Antibody, 528 J. Biol. Chem., January 11, 2008; 283(2): 1156 - 1166. [Abstract] [Full Text] [PDF]

				S.-W. Chi, C.-Y. Maeng, S. J. Kim, M. S. Oh, C. J. Ryu, S. J. Kim, K.-H. Han, H. J. Hong, and S. E. Ryu Broadly neutralizing anti-hepatitis B virus antibody reveals a complementarity determining region H3 lid-opening mechanism PNAS, May 29, 2007; 104(22): 9230 - 9235. [Abstract] [Full Text] [PDF]