Strong Immune System Research Articles

New evidence for role of glutathione in HIV infection

Glutathione may be one of the keys to a strong immune system in patients with AIDS. This finding has many clinical implications for patients, as it suggests that certain glutathione-depleting drugs should be avoided, and that the glutathione prodrug acetylcysteine may be able to boost the immune system of particular patient groups. The latest evidence supporting such a role for glutathione was presented at the Joint Meeting of the American Academy of Allergy, Asthma and Immunology, the American Association of Immunologists and the Clinical Immunology Society [ San Francisco, US; February 1997 ].

Structure—Function Relationship among Quillaja Saponins Serving as Excipients for Nasal and Ocular Delivery of Insulin

AbstractThe purpose of this investigation was to explore the structure–function relationship among naturally occurring Quillaja saponins and derivatives for their ability to stimulate insulin delivery from nosedrops and eyedrops and to test the hypothesis that stimulation of peptide drug delivery was correlated with surfactant strength. Native saponins, including QS-21, were purified from an aqueous extract of Quillaja saponaria bark by adsorption chromatography and HPLC. Native saponins were then deacylated by mild alkaline hydrolysis to form DS-1 and DS-2, derivatives that are smaller and more hydrophilic than their parent compounds. DS-1 was further treated either to reduce an aldehyde residue to form DS-1(R) or to remove the fucose-containing oligosaccharide to form QH-957. Rats receiving eyedrops or nosedrops formulated with insulin, but without any Quillaja saponins, showed no hypoglycemic response. Rats receiving eyedrops or nosedrops formulated with insulin plus saponins showed a dose-dependent hypoglycemic response, with the following rank order: QS-21>DS-1>DS-1(R)>DS-2>QH-957. Surfactant strength was determined by measurement of the critical micellar concentration (cmc) and hemolysis of sheep erythrocytes. The cmc was lowest for the parent saponins QS-21 and QS-18, and increased for the deacylated saponin derivatives DS-1, DS-2, and QH-957; hemolysis of sheep erythrocytes was observed at low concentrations (∼0.006mM) of the parent saponins, QS-21 and QS-18, at intermediate concentrations (0.06–0.08mM) of DS-1 and DS-2, and at higher concentrations of DS-1(R) (0.45mM) and QH-957 (1.5mM). Hence, efficacy as an absorption-enhancing agent was greatest in those saponins with the lowest hemolytic titers and cmc values. However, this relationship was not a strict one, because DS-1, which differs from DS-2 only in the absence of one glucose residue, was significantly more potent than DS-2 in stimulating the absorption of insulin. DS-1 and DS-2 share a similar cmc and hemolytic titer, so this difference in efficacy must be due to some specificity beyond simple surfactant strength. Furthermore, DS-1 does not trigger an immune response when administered to animals, whereas QS-21 is a strong immune system activator. Therefore, DS-1 has emerged as an interesting candidate for inclusion in an eyedrop or nosedrop formulation.

Immune surveillance and natural resistance: an evaluation.

Concepts in tumour immunology are changing fundamentally. Around 1970 tumour immunology contained the following related concepts: Thousands of tumour cells arise de novo each day. Tumour cells are antigenic in their host. All these antigenic tumour cells are killed by a strong immune surveillance system. A more likely set of concepts looks as follows: Tumour cells do not arise frequently. Tumour cells may be antigenic or not. There is no need to postulate a very strong immune surveillance or natural resistance system. In this paper I am reviewing our present knowledge of immune surveillance and natural resistance. Only scanty information appears to be available. This information suggests that virally induced tumours are usually killed by cytotoxic T lymphocytes, and natural killer cells, whereas immune surveillance and natural resistance against other tumours may be quite weak.

Methods for improving cereal protein quality.

Three methods for improving cereal protein quality are discussed. Two older methods are supplementation with limiting essential amino acids and with protein concentrates high in those amino acids. The most recent method (since 1964) is the replacement of the normal cereal grain with its high lysine mutant counterpart. Three high lysine cereals are now available, corn, barley, and sorghum. In animal feeding, least cost formulas will determine which of the three improvement methods will be used. In human nutrition, cost, availability, palatability and acceptance are all equally important factors. In animals, pounds of gain per pound of feed will be the final measure of cereal protein quality. In humans, especially preschool children, the most important criterion will be the ability of the improved cereal protein to build a strong immune defense system. Animal studies show that protein quality is more important than calories when calories are restricted to less than ad libitum consumption. It is therefore essential that children restricted in their total energy intake have the best cereal protein quality possible to protect their immune system.