Depressed natural killer and lectin-induced cell-mediated cytotoxicity in cholesterol-fed guinea pigs.
Dunkin-Hartley and Hartley guinea pigs were fed a diet containing 1% cholesterol (C+) or a control diet (C-). The C+-fed guinea pigs showed a decrease in antitumor effector cell levels as measured by an in vitro 18-hour 51Cr release assay. Natural killer (NK) activity fell rapidly after initiation of cholesterol feeding, decreasing to 25.6% of control levels by 2 weeks. While the interferon inducer polyinosinic-polycytidylic acid increased NK activity as much as 3.6-fold in controls, the NK levels in C+-fed animals were not increased. NK activity was lower in both spleen and peripheral blood of C+-fed animals and against K562, MOLT-3, HL-60, and Raji target cells. Lectin-dependent cell-mediated cytotoxicity was increased in the C+-fed group over, the first 1-2 weeks on the diet, but it dropped to low levels by 6 weeks. Lipoprotein preparations from plasmas of both C+- and C--fed animals inhibited NK cell activity, but suppression was not due to lipoprotein cholesterol content. On the basis of lipoprotein protein, lipoproteins from C--fed animals were more suppressive. The results suggest that the decrease in cytotoxicity induced by dietary cholesterol is due to more than the high levels of plasma and lipoprotein cholesterol.
D000818:Animals; D000920:Antibody-Dependent Cell Cytotoxicity / Q000187:drug effects*; D002784:Cholesterol / Q000097:blood; D002791:Cholesterol, Dietary / Q000008:administration & dosage / Q000494:pharmacology*; D006168:Guinea Pigs; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D007700:Kinetics; D037102:Lectins / Q000494:pharmacology*; D008074:Lipoproteins / Q000494:pharmacology; D008297:Male; D013154:Spleen / Q000166:cytology
D002791:Cholesterol, Dietary; D037102:Lectins; D008074:Lipoproteins; D002784:Cholesterol