TNF-ALPHA PRIMES POLYMORPHONUCLEAR LEUKOCYTES FOR AN ENHANCED RESPIRATORY BURST TO A SIMILAR EXTENT AS BACTERIAL LIPOPOLYSACCHARIDE

[摘要] We examined whether preincubating polymorphonuclear leukocytes (PMN) with TNF-alpha would result in an enhanced respiratory burst upon subsequent stimulation by various agents. Bacterial lipopolysaccharide (LPS), a known primer of PMN, was used as control. We found that both LPS (0.01 to 10.0-mu-g/ml) and recombinant TNF-alpha (0.001 to 1.0-mu/ml) act as direct stimulants of PMN as measured by chemiluminescence. Sixty minutes of preincubation of PMN with 1 mu-g/ml TNF-alpha or 10 mu-g/ml LPS resulted in similar priming for the respiratory burst elicited by opsonized zymosan, phorbol myristate acetate, zymosan, zymosan-activated serum, aggregated immunoglobulin, and f-met-leu-phe (FMLP) depending on the method of measurement used, i.e., chemiluminescence, production of O2-, and H2O2. Priming with TNF-alpha for an enhanced response to stimulation by FMLP could be abrogated by anti-TNF-alpha antibody. Cell-surface receptor numbers and binding-affinity constants for FMLP remained stable under conditions leading to priming. We conclude that TNF-alpha is able to prime PMN for an enhanced respiratory burst to a similar extent as with LPS. Because PMN cell-surface receptors for FMLP are unaltered by priming, the enhanced respiratory burst seems to be due to changes in intracellular metabolism.

[发布日期] 1990-12-01

[效力级别]  Proceedings Paper