title: The regulating effect of cholesterol derivatives isolated from human sera on lymphocyte response to phytohemagglutinin.
abstract: Cholesterol derivatives, including 7 alpha-hydroxycholesterol (7 alpha-HC), 7 beta-hydroxycholesterol (7 beta-HC), and 7-ketocholesterol (7-KC), were isolated from the Cohn fraction IV-I of normal human sera and were shown to be the moieties responsible for the suppression of lymphocyte proliferation. When 5-10 micrograms/ml of 7 alpha-HC, 7 beta-HC or 7-KC were added in vitro to lymphocyte cultures, incorporation of 3H-thymidine (3H-TdR) into the lymphocyte DNA was suppressed by about 50% when compared with the control. When 10-50 mg/kg/day of 7 alpha-HC, 7 beta-HC and 7 KC were administered in vivo to skin grafts on rats, the prolongation of skin grafts was observed. The concentration of 7-KC in cancer patient sera was 2 to 3 times the amount in normal pooled human sera.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000494:pharmacology; D006085:Graft Survival / Q000187:drug effects; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood / Q000494:pharmacology*; D007653:Ketocholesterols / Q000097:blood / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009369:Neoplasms / Q000097:blood; D010835:Phytohemagglutinins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D010948:Viral Plaque Assay
chemical_list: D006888:Hydroxycholesterols; D007653:Ketocholesterols; D010835:Phytohemagglutinins; C011724:cholest-5-en-3 beta,7 alpha-diol; D002784:Cholesterol; C003001:7-ketocholesterol