Modulation of Animal and Human Hematopoiesis by beta-Glucans: A Review
beta-Glucans are cell wall constituents of bacteria, yeast, fungi, and plants. They are not expressed in mammalian cells, but they are recognized by mammalian cells as pathogen-associated molecular patterns by pattern recognition receptors and thus act as biological response modifiers. This review summarizes data on the hematopoiesis-stimulating effects of beta-glucans, as well as on their ability to enhance bone marrow recovery after an injury. beta-Glucans have been shown to support murine hematopoiesis suppressed by ionizing radiation or cytotoxic anti-cancer therapy. They also enhance stem cell homing and engraftment. Basically, two forms of beta-glucan preparations have been investigated, namely particulate and soluble ones. beta-Glucans are generally well tolerated, the particulate forms showing a higher incidence of undesirable side effects. Taken together, the hematopoiesis-stimulating properties of beta-glucans predetermine these biological response modifiers to ever increasing use in human medicinal practice.