Interactions of multilamellar phospholipid vesicles with bovine lymphocytes: effects of alpha-tocopherol on lymphocyte blastogenesis.

Multilamellar lipid vesicles (MLV) composed of egg yolk lecithin (EYL) suppressed the response of bovine peripheral blood lymphocytes (BPBL) to phytohemagglutinin (PHA). EYL contains 18:1 and 18:2 as the major unsaturated phospholipids. Dioleoyllecithin (DOL; cis 9) MLV did not suppress BPBL blastogenesis. Dilinoeyllecithin (DLL; cis, cis 9, 12) MLV suppressed BPBL blastogenesis. The suppressive effect could be reversed by increasing the MLV DML concentration. The addition of alpha-tocopherol (alpha-T) at 10 mole% into MLV containing DLL reversed blastogenic suppression of BPBL. MLV composed of mixed saturated phospholipids (dimyristoyllecithin and dipalmitoyllecithin) and alpha-T enhanced the BPBL blastogenic response to PHA. BPBL incubated with varying PHA concentrations (11.82-375 mg/ml) and a constant concentration (2 mumoles/ml) of MLV composed of EYL remained suppressed either when PHA and MLV were added simultaneously or when MLV were incubated for 1 hr prior to the addition of PHA. This suggests that alpha-T may act as an immunomodulator in the blastogenic response to PHA. Results suggest that alpha-T reversion of EYL suppression of BPBL blastogenesis may be due to interactions of alpha-T with unsaturated acyl chains in EYL phospholipids.