Immune-stimulating complexes ISCOMs

Many compounds can act as adjuvants. Their classification is made difficult by the variety in chemical composition and the overlapping, often poorly understood, mechanisms of action. Only aluminum adjuvants are approved by the FDA for use in human vaccines. Quil A is a saponin that is commonly used as an adjuvant in veterinary vaccines and is also a component of immune-stimulating complexes (ISCOM). These adjuvants are addressed in some detail below. A detailed discussion of other types of adjuvants can be found in recent books and reviews on this subject. 

IP4 Inositol tetrakisphosphate IPF Idiopathic pulmonary fibrosis IPO Intestinal peroxidase IpOCOCq Isopropylidene OCOCq I/R Ischaemia-reperfusion IRAP IL-1 receptor antagonist protein IRF-1 Interferon regulatory factor 1 la Short-circuit current ISCOM Immune-stimulating complexes... 

Iscoms (Immune-stimulating complexes) are stable complexes of cholesterol, phospholipid, and Quil A (derived from Quillaja saponaria) in size ranges from 40 to lOOnm. They are promising carriers for antigens in subunit vaccines. Iscoms are considered to be multi-micellar structures, shaped and stabilized by hydro-phobic interactions, electrostatic repulsion, steric factors and possibly hydrogen bonds. Protection... 

ISCOMs are stable (non-covalent) complexes composed of a mixture of Quil A, cholesterol and (an amphipathic) antigen. ISCOMs stimulate both humoral and cellular immune responses and have been used in the production of some veterinary vaccines. Their use in humans, however, has not been licensed so far, mainly due to safety concerns relating to the Quil A component. 

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