Are botanical glucans effective in enhancing host immune response to tumors?
Susanna Cunningham-Rundles, The Weill Medical College, Cornell University Mushroom polysaccharides, particularly beta-glucans, have antitumor and immunostimulating properties. These polysaccharides do not directly attack cancer cells but instead exert their effects by activating immune responses in the host. Betafectin (PGG-glucan) enhances hematopoietic recovery in immune-suppressed mice and primates by synergizing with myeloid growth factors. Another beta-glucan, soluble branched (1,4)-beta-D-glucan, augments NK cell activity and CTL responses to enhance antitumor activities against MHC class I negative and class I positive malignant melanoma. Use of beta-glucans as adjuvants for monoclonal antibody treatment has also been explored, because beta-glucans bind to the complement receptor 3 (iC3B) and could enhance leukocyte killing of tumor cells coated with iC3B through naturally occurring antitumor antibodies. Beta-glucans also appear to recruit tumoricidal granulocytes, dramatically
