Immunomodulators from plants and fungi

This discovery of the regulation of the immune response by hormone‐like proteins (lymphokines) offers opportunities for the search for novel and specific immunomodulators through new screening procedures; it has also assisted the analysis of the mechanism of action of established immunomodulators. This is illustrated by reference to a range of immunomodulators of plant or fungal origin, chosen for the recent progress in the understanding of their mechanism of action, or their potential clinical importance. These are the vaccine adjuvant saponin, the non‐specific immunostimulators lentinan and krestin (fungal polysaccharides) and bestatin (a fungal peptide) and the immunosuppressive fungal peptide cyclosporin A.