Published in Cancer Detection and Prevention 2000; 24(1):100-106.

Polyethylene Glycol-Modified Concanavalin A as an Effective Agent to Stimulate Anti-Tumor Cytotoxicity

Tomoo Ueno, Kenji Ohtawa, Yasuhiko Kimoto, M.D., Katsukiyo Sakural, Ph.D., Yoh Kodera, Ph.D., Misao Hiroto, Ayako Matsushima,Ph.D., Hiroyuki Nishimura, Ph.D., and Yuji Inada, Ph.D.

Toin Human Science and Technology Center HUSTEC, Department of Biomedical Engineering,Toin University of Yokohama, 1614 Kurogane-cho, Aoba-ku, Yokohama 225-8502, Japan,Department of Surgical Oncology, Osaka University Medical School, 2-2 Yamada-oka, Suita,Osaka 565-0871, Japan

Address all correspondence to: Yuji Inada, Toin Human Science and Technology Center (HUSTEC), Department of BiomedicalEngineering, Toin University of Yokohama, 1614 Karogane-cho, Aoba-ku, Yokohama 225-8502, Japan. Tel: +81-45-974-5060.Fax: +81-45-972-5972

ABSTRACT The jack bean lectin, concanavalin A (Con A), was modified with 2,4-bis[O-methoxypoly(ethyleneglycol)I-6-chloro-s-triazine, activated PEG2, to form PEG-Con A. The immunoreactivity of PEG-Con A towardsanti-Con A antibodies was reduced by increasing the degree of modification of amino groups in the Con Amolecule. PEG-Con A had a complete reduction of the immunogenicity in mice and prolonged the clearance-timein blood. Although the mitogenic activity of Con A towards murine spleen cells was reduced by the conjugationwith activated PEG,, the administration of PEG-Con A to mice enhanced the anti-tumor cytoloxicily of peripherallymphocytes against melanoma B 16 cells.

KEY WORDS: polyethylene glycol, concanavalin A, cytotoxic T cell, mitogenic activity, chemical.