Lymphocyte activation: Rapid changes in the phospholipid metabolism of plasma membranes during stimulation

Publisher Website
Google Scholar
Abstract
Lymph node lymphocytes from normal or BCG‐sensitized rabbits were stimulated by phytohemagglutinin (PHA) or purified protein derivative of tuberculin (PPD). After incubation of intact lymphocytes with [14C]oleate, the cells were disrupted and microsomes (consisting of plasma membrane and endoplasmic reticulum) were isolated. In some experiments the microsomal fraction was separated into plasma membrane and endoplasmic reticulum by dextran gradient centrifugation.After 10 min microsomes from PHA‐stimulated lymphocytes had incorporated 3 times more [14C]oleate into lecithin than microsomes from controls. With PPD as antigen, after 1 h incubation a significant increase in the incorporation of [14C]oleate into microsomal lecithin was detected. The stimulation index with respect to [14C]oleate uptake remained constant in both cases when the lymphocytes were cultured for longer times. Approximately 90 % of the [14C]oleate incorporated into microsomal lecithin was recovered in the plasma membrane which exhibited the highest stimulation. The results are discussed in relation to possible biochemical events underlying the triggering process of lymphocytes.