Phosphatidylinositol response and proliferation of oxidative enzyme-activated human T lymphocytes: suppression by plasma lipoproteins
The phosphatidylinositol (PI) response and DNA synthesis of neuraminidase and galactose oxidase (NAGO)-stimulated human T lymphocytes are suppressed by low density lipoproteins (LDL). To understand the mechanism of lymphocyte activation more fully, the PI response and DNA synthesis and suppression of these events by LDL in NAGO-stimulated T lymphocytes were characterized. Between 30 min and 6 hr after NAGO stimulation, there was an increase of /sup 32/Pi incorporation into PI without increased incorporation into the phosphorylated forms of PI or into other phospholipids. DNA synthesis as determined by (/sup 3/H)thymidine incorporation depended on the lymphocyte-accessory monocyte ratio and total cell density. Optimal stimulation of the PI response and DNA synthesis occurred at the same concentration of neuraminidase and galactose oxidase. While the PI response was only partially suppressed by LDL with optimal suppression at 10 to 20 micrograms of protein/ml, DNA synthesis was completely suppressed although at much higher LDL concentrations, greater than 100 micrograms protein/ml. As monocyte numbers are increased, LDL suppression of DNA synthesis is decreased. The ability of NAGO to stimulate the PI response and DNA synthesis in a similar way, and the suppression of both events by LDL, suggests the PI response is important for lymphocyte activation and proliferation. Stimulation of human T lymphocytes by oxidative mitogens, neuraminidase, and galactose oxidase caused increased phosphatidylinositol metabolism and increased DNA synthesis. Both responses were suppressed by low density lipoproteins.
- Research Organization:
- Indiana Univ., Bloomington
- OSTI ID:
- 5828940
- Journal Information:
- J. Lipid Res.; (United States), Vol. 25:11
- Country of Publication:
- United States
- Language:
- English
Similar Records
Stimulation of LDL receptor activity in Hep-G2 cells by a serum factor(s)
Receptor-mediated uptake of low density lipoprotein stimulates bile acid synthesis by cultured rat hepatocytes
Related Subjects
HYDROLASES
BIOSYNTHESIS
INOSITOLS
METABOLISM
LYMPHOCYTES
CELL PROLIFERATION
DNA REPLICATION
OXIDOREDUCTASES
LABELLED COMPOUNDS
LIPOPROTEINS
MITOGENS
PHOSPHORUS 32
REDOX REACTIONS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ENZYMES
ISOTOPE APPLICATIONS
ISOTOPES
LEUKOCYTES
LIGHT NUCLEI
LIPIDS
MATERIALS
MONOSACCHARIDES
NUCLEI
NUCLEIC ACID REPLICATION
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
PROTEINS
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS
SYNTHESIS
550201* - Biochemistry- Tracer Techniques