Recognition of self and nonself, the crucial role of phagocytosis and lysosomal destruction of antigen

Botanical polysaccharides: macrophage immunomodulation and therapeutic potential

Botanical polysaccharides exhibit a number of beneficial therapeutic properties, and it is thought that the mechanisms involved in these effects are due to the modulation of innate immunity and, more specifically, macrophage function. In this review, we summarize our current state of understanding of the macrophage modulatory effects of botanical polysaccharides isolated from a wide array of different species of flora, including higher plants, mushrooms, lichens and algae. Overall, the primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, leading to immunomodulation, anti-tumor activity, wound-healing and other therapeutic effects. Furthermore, botanical and microbial polysaccharides bind to common surface receptors and induce similar immunomodulatory responses in macrophages, suggesting that evolutionarily conserved polysaccharide structural features are shared between these organisms. Thus, the evaluation of botanical polysaccharides provides a unique opportunity for the discovery of novel therapeutic agents and adjuvants that exhibit beneficial immunomodulatory properties.

Axonal regeneration in experimental allergic peripheral neuritis

It has recently been suggested that severed axons fail to regenerate in the mammalian central nervous system as a result of an autoimmune reaction to myelin basic protein released into the circulation at the time of injury. Since the autoantigenic components of peripheral myelin are rapidly phagocytosed after axonal transection, it is claimed that a comparable immune response does not occur following injury to peripheral nerves, so the regenerative process is not hindered. If this contention is correct, it should be possible to inhibit the regeneration of peripheral axons by inoculating animals with suitable neuritogenic homogenates of peripheral nervous tissue. It has been shown that axonal regneration proceeds at the same rate in rats with experimental allergic neuritis as in healthy controls inoculated only with Freund's adjuvant. It is unlikely, therefore, that myelin basic proteins can stimulate the production of antibodies capable of inhibiting regenerative axonal growth.