Priming of the respiratory burst of bone marrow-derived macrophages is associated with an increase in protein kinase C content

Abstract

The biochemical mechanism(s) underlying the priming of the macrophage for an enhanced PMA-induced respiratory burst is not understood. Because the cellular receptor for PMA is thought to be protein kinase C (PKC), we have investigated the effects of priming agents on cellular PKC levels. Sonicates from unprimed bone marrow-derived macrophages (BMM) were found to contain PKC activity (309 ± 51 pmol 32P-incorporated/mg/min; mean ± SE, n = 17) as measured by the phospholipid-, diacylglycerol-, and calcium-dependent phosphorylation of histone. Exposure of BMM to priming agents such as TNF-α, LPS, and granulocyte/macrophage-CSF resulted in a significant increase in both histone-phosphorylating ac..