摘要
A series of artificial membranes called small unilaminar vesicles (SUVs) comprising different molar ratios of phosphatidylcholine (PC)/cholesterol (Ch) were constructed and exogenous PC and Ch were transferred into human peripheral blood lymphocytes through incubating the cells with SUVs in order to study the effects of the changed constituents of membrane lipids on the expression of CD 71 in lymphocytes, the binding characteristics of CD 71 molecules with its ligand and its internalization. It was found that after the treatment of SUVs, the Ch content in the plasmic membrane was increased with a decrease of PC/Ch ratio. After incubation with ConA for 48 h,the percentage of CD 71-positive lymphocytes increased with the increase of the availab1e binding sites for CD 71 to its ligand, but the affinity of CD 71 with its ligand was lowered- When Ch synthesis was blocked with HMG-CoAreductase inhibitor (Lovastatin), the number of CD71 molecules was obviously reducce but the afinity of CD 71with its ligand elevated- It is believed that that the construction of the lipid environment can directly affect the properties of CD 71 molecules. Less fluid phase of the lipid environment might be suitable to the move;nent of CD 71 in the membrane but minimize the tendency for CD 71 to maintain a con formation of high affinity state.
A series of artificial membranes called small unilaminar vesicles (SUVs) comprising different molar ratios of phosphatidylcholine (PC)/cholesterol (Ch) were constructed and exogenous PC and Ch were transferred into human peripheral blood lymphocytes through incubating the cells with SUVs in order to study the effects of the changed constituents of membrane lipids on the expression of CD 71 in lymphocytes, the binding characteristics of CD 71 molecules with its ligand and its internalization. It was found that after the treatment of SUVs, the Ch content in the plasmic membrane was increased with a decrease of PC/Ch ratio. After incubation with ConA for 48 h,the percentage of CD 71-positive lymphocytes increased with the increase of the availab1e binding sites for CD 71 to its ligand, but the affinity of CD 71 with its ligand was lowered- When Ch synthesis was blocked with HMG-CoAreductase inhibitor (Lovastatin), the number of CD71 molecules was obviously reducce but the afinity of CD 71with its ligand elevated- It is believed that that the construction of the lipid environment can directly affect the properties of CD 71 molecules. Less fluid phase of the lipid environment might be suitable to the move;nent of CD 71 in the membrane but minimize the tendency for CD 71 to maintain a con formation of high affinity state.