Rat peripheral blood lymphocytes (PBL) were cultured for four days with or without PHA in the presence of increasing concentrations of LDL. Low doses of LDL (0.5 μg/ml) were found to stimulate PBL proliferation measured both by (3H) thymidine incorporation and cell count, demonstrating that in controlled conditions (i.e. the absence of serum) cell replication is strongly dependent from exogenous cholesterol availability. Furthermore, a set of experiments has been performed on PBL from rats previously treated with a derivative of clofibrate (ronifibrate) which is known to decrease the circulating level of cholesterol. These experiments have clearly indicated that lymphocytes from treated rats, in the presence of PHA and low concentration of LDL (0.5 μg/ml) display a higher degree of proliferation as measured by (3H) thymidine incorporation and cell count. Doses of LDL higher than 0.5 μg/ml were found to inhibit cell proliferation more strongly in the case of PBL from drug-tested rats than in that of PBL from untreated animals. On the basis of this latter finding we could suggest that drug treatment induces an increase of LDL receptors on the cell membrane. Finally, PBL from both normal and drug-treated rats do respond in the same fashion to IL-2, PHA alone or soluble antigen indicating that cell functions have not been altered by drug administration. On the whole, the present results suggest that this method may be useful in order to measure the status of LDL receptor in PBL.
Peripheral blood lymphocytes activation: Sterol metabolism and LDL receptor
Tavazzi B;
1990-01-01
Abstract
Rat peripheral blood lymphocytes (PBL) were cultured for four days with or without PHA in the presence of increasing concentrations of LDL. Low doses of LDL (0.5 μg/ml) were found to stimulate PBL proliferation measured both by (3H) thymidine incorporation and cell count, demonstrating that in controlled conditions (i.e. the absence of serum) cell replication is strongly dependent from exogenous cholesterol availability. Furthermore, a set of experiments has been performed on PBL from rats previously treated with a derivative of clofibrate (ronifibrate) which is known to decrease the circulating level of cholesterol. These experiments have clearly indicated that lymphocytes from treated rats, in the presence of PHA and low concentration of LDL (0.5 μg/ml) display a higher degree of proliferation as measured by (3H) thymidine incorporation and cell count. Doses of LDL higher than 0.5 μg/ml were found to inhibit cell proliferation more strongly in the case of PBL from drug-tested rats than in that of PBL from untreated animals. On the basis of this latter finding we could suggest that drug treatment induces an increase of LDL receptors on the cell membrane. Finally, PBL from both normal and drug-treated rats do respond in the same fashion to IL-2, PHA alone or soluble antigen indicating that cell functions have not been altered by drug administration. On the whole, the present results suggest that this method may be useful in order to measure the status of LDL receptor in PBL.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
