Research Abstract

Expert Opinion on Biological Therapy
May 2005, Vol. 5, No. 5, Pages 691-702

Yeast Whole Glucan Particle β-glucan in Conjunction with Antitumour Monoclonal Antibodies to Treat Cancer

Jun Yan, Daniel J Allendorf & Brian Brandley

James Graham Brown Cancer CenterTumour Immunobiology Program, University of Louisville, 580 S. Preston Street, Louisville, KY 40202 USA
Tel: +1 502 852 3628; Fax: +1 502 852 2123;
E-mail: jun.yan@louisville.edu

Abstract

Beta-glucans, biological response modifiers (BRMs) derived from the cell walls of yeast and other sources, have been demonstrated to prime leukocyte c-omplement receptor 3 (CR3), thus enabling these cells to kill tumours opsonised with complement fragment iC3b. Many tumours
activate complement via the classical pathway mediated by antitumour monoclonal antibodies (mAbs) or natural antibodies. Studies into the cellular and molecular mechanisms of action have demonstrated that orally administrated yeast β-glucans are ingested and processed by
macrophages. These macrophages secrete the active moiety that primes neutrophil CR3 to kill iC3b-opsonised tumour cells. Extensive studies in preclinical animal tumour models have demonstrated the efficacy of combined oral particulate yeast β-glucan with antitumour mAb
therapy in terms of tumour regression and long-term survival. It is proposed that the addition of β-glucan will further improve the clinical therapeutic efficacy of antitumour mAbs in cancer patients.