Membrane receptors for very low density lipoprotein (VLDL) inhibitor of lymphocyte proliferation

Journal Article · Mon Jun 01 04:00:00 EDT 1981 · Blood; (United States)

OSTI ID:5394264

Yi, P I; Beck, G; Zucker, S

Physiologic concentrations of human plasma very low density lipoproteins inhibit the DNA synthesis of lymphocytes stimulated by allogeneic cells or lectins. In this report reachers have compared the effects of isolated lipoproteins (very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL)) and lipoprotein-depleted plasma (LDP) on DNA synthesis by phytohemagglutinin-stimulated human lymphocytes. The relative potency for the inhibition of lymphocyte proliferation was VLDL greater than LDL greater than HDL greater than LDP. Fifty percent inhibition of DNA synthesis was observed at a VLDL protein concentration of 1.5--2.0 microgram/ml. Researchers have further demonstrated the presence of specific receptors for VLDL on human lymphocytes. Native VLDL was more effective than LDL in competing for 125I-VLDL binding sites. Subsequent to binding to lymphocytes, 125I-VLDL was internalized and degraded to acid-soluble products. Based on a Scatchard analysis of VLDL binding at 4 degrees C, the number of VLDL receptors per lymphocyte was estimated at 28,000 +/- 1300. Based on an estimated mean binding affinity for the VLDL receptor complex at half saturation of approximately 8.8 X 10(7) liter/mole, it is estimated that 91% of lymphocyte VLDL receptors are occupied at physiologic VLDL concentrations in blood. Although the immune regulatory role of plasma lipoproteins is uncertain, researchers suggest tha VLDL and LDL-In may maintain circulating blood lymphocytes in a nonproliferative state via their respective cell receptor mechanisms.

• OSTI ID: 5394264
• Journal Information: Blood; (United States), Journal Name: Blood; (United States) Vol. 57:6; ISSN BLOOA
• Country of Publication: United States
• Language: English

Related Subjects

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550301 -- Cytology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
BINDING ENERGY
BIOLOGICAL MATERIALS
BIOSYNTHESIS
BLOOD
BLOOD CELLS
BLOOD CIRCULATION
BLOOD PLASMA
BODY FLUIDS
CELL CONSTITUENTS
CELL MEMBRANES
COMPARATIVE EVALUATIONS
CONNECTIVE TISSUE CELLS
DNA
ENERGY
IMMUNITY
INHIBITION
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LEUKOCYTES
LIPIDS
LIPOPROTEINS
LYMPHOCYTES
MATERIALS
MEMBRANES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PHYSIOLOGY
PROTEINS
RECEPTORS
SOMATIC CELLS
SYNTHESIS
TRACER TECHNIQUES