Inhibition of sterol and DNA syntheses in phytohemagglutinin-stimulated human lymphocytes by 7 alpha-hydroxycholesterol.
Sterol and DNA syntheses were induced in human peripheral blood lymphocytes stimulated with phytohemagglutinin (PHA). DNA synthesis in the PHA-stimulated lymphocytes was suppressed by 7 alpha-hydroxycholesterol (7 alpha-HC). The maximum suppression of DNA synthesis was observed when 7 alpha-HC was added in the culture within 6 hr of PHA stimulation to the lymphocytes. However, as the concentration of fetal bovine serum (FBS) in the culture medium was increased, the inhibitory effect of 7 alpha-HC on the syntheses of sterol and DNA were decreased. Furthermore, low and high density lipoproteins completely reversed the inhibition of DNA synthesis by 7 alpha-HC. These results suggest that cholesterol is an essential requirement of lymphocyte blastogenesis regardless of whether the source of the sterol is exogenous or endogenous.
D002784:Cholesterol / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis*; D005312:Fetal Blood / Q000502:physiology; D006801:Humans; D006888:Hydroxycholesterols / Q000494:pharmacology*; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000378:metabolism*; D010835:Phytohemagglutinins / Q000494:pharmacology*; D013261:Sterols / Q000096:biosynthesis*
D006888:Hydroxycholesterols; D010835:Phytohemagglutinins; D013261:Sterols; C011724:cholest-5-en-3 beta,7 alpha-diol; D004247:DNA; D002784:Cholesterol