Biomaterial Database

Regulatory serum lipoproteins: regulation of lymphocyte stimulation by a species of low density lipoprotein. 1976

L K Curtiss, and T S Edgington

Low density lipoproteins (LDL) containing apolipoprotein B were separated from 15 fresh normal human serum pools by three independent isolation methods including sequential ultracentrifugal flotation, affinity chromatography, and polyanion precipitation. A discrete subpopulation of LDL (LDL-In) was isolated which possessed comparable inhibitory activity for PHA, PWM, and allogenic cell stimulated human lymphocytes in vitro at concentrations of 1 to 10 mug protein/1 x 10(5) lymphocytes/0.25 ml culture. LDL-In was characterized by a mean buoyant density of 1.055 g/ml in KBr, a m.w. of 2 to 3 x 10(6) daltons and a composition of 20 to 25% protein and 75 to 80% lipid with beta electrophoretic mobility. The biologic activity of LDL-In was non-cytotoxic, independent of mitogen concentration, and dependent upon the concentration of serum in the culture assay. The effect was temporally dependent requiring approximately 24 hr for induction of a stable suppressed state. Suppression was reversible with shorter periods of exposure to LDL-In. LDL-In did not inhibit lymphocytes at periods greater than 19 hr after stimulation, suggesting that LDL-In may influence metabolis events associated with the inductive phase of lymphocyte activation by lectins and allogeneic cells. LDL-In was clearly distinguishable from T lymphocyte E rosette inhibitory factor since it did not influence E rosette function of lymphocytes. The physicochemical and biologic properties of LDL-In clearly distinguish this reguloratory lipoprotein from previously described immunoregulatory factors.

UI	MeSH Term	Description	Entries
D007104	Immune Adherence Reaction	A method for the detection of very small quantities of antibody in which the antigen-antibody-complement complex adheres to indicator cells, usually primate erythrocytes or nonprimate blood platelets. The reaction is dependent on the number of bound C3 molecules on the C3b receptor sites of the indicator cell.	Adherence Reaction, Immune,Adherence Reactions, Immune,Immune Adherence Reactions,Reaction, Immune Adherence,Reactions, Immune Adherence
D008077	Lipoproteins, LDL	A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.	Low-Density Lipoprotein,Low-Density Lipoproteins,beta-Lipoprotein,beta-Lipoproteins,LDL(1),LDL(2),LDL-1,LDL-2,LDL1,LDL2,Low-Density Lipoprotein 1,Low-Density Lipoprotein 2,LDL Lipoproteins,Lipoprotein, Low-Density,Lipoproteins, Low-Density,Low Density Lipoprotein,Low Density Lipoprotein 1,Low Density Lipoprotein 2,Low Density Lipoproteins,beta Lipoprotein,beta Lipoproteins
D008213	Lymphocyte Activation	Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.	Blast Transformation,Blastogenesis,Lymphoblast Transformation,Lymphocyte Stimulation,Lymphocyte Transformation,Transformation, Blast,Transformation, Lymphoblast,Transformation, Lymphocyte,Activation, Lymphocyte,Stimulation, Lymphocyte
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D002846	Chromatography, Affinity	A chromatographic technique that utilizes the ability of biological molecules, often ANTIBODIES, to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Chromatography, Bioaffinity,Immunochromatography,Affinity Chromatography,Bioaffinity Chromatography
D002850	Chromatography, Gel	Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.	Chromatography, Exclusion,Chromatography, Gel Permeation,Chromatography, Molecular Sieve,Gel Filtration,Gel Filtration Chromatography,Chromatography, Size Exclusion,Exclusion Chromatography,Gel Chromatography,Gel Permeation Chromatography,Molecular Sieve Chromatography,Chromatography, Gel Filtration,Exclusion Chromatography, Size,Filtration Chromatography, Gel,Filtration, Gel,Sieve Chromatography, Molecular,Size Exclusion Chromatography
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014461	Ultracentrifugation	Centrifugation with a centrifuge that develops centrifugal fields of more than 100,000 times gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
D037102	Lectins	Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.	Animal Lectin,Animal Lectins,Isolectins,Lectin,Isolectin,Lectin, Animal,Lectins, Animal
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In