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Generation of Human CD40-activated B cells
Published on: October 17, 2009
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gp91phox-dependent expression of platelet CD40 ligand
P Pignatelli1, V Sanguigni, L Lenti
1Divisione IV Clinica Medica, Dipartimento di Medicina Sperimentale e Patologia, Università di Roma La Sapienza, Policlinico Umberto I, 00185, Rome, Italy.
Circulation
|July 14, 2004
Summary
Platelet CD40 ligand (CD40L) expression is triggered by agonists. This study reveals CD40L expression is mediated by arachidonic acid via gp91phox activation in platelets.
Area of Science:
- Immunology
- Hematology
- Biochemistry
Background:
- Platelet CD40 ligand (CD40L) expression is agonist-mediated, but the mechanism remains unclear.
- Understanding this mechanism is crucial for platelet function research.
Purpose of the Study:
- To elucidate the mechanism behind agonist-induced CD40L expression on platelets.
- To investigate the role of reactive oxygen species and arachidonic acid pathways.
Main Methods:
- Measuring CD40L expression in human platelets with and without antioxidants or PLA2 inhibitors.
- Analyzing platelets from patients with inherited gp91phox deficiency.
- Performing immunoprecipitation to detect gp91phox expression.
Main Results:
- Superoxide dismutase inhibited agonist-induced platelet CD40L expression.
- Platelets from healthy subjects express gp91phox.
- Patients deficient in gp91phox showed absent superoxide anion and CD40L expression.
- PLA2 inhibition prevented agonist-induced O(2)(-) and CD40L expression.
Conclusions:
- Platelet CD40L expression is mediated by arachidonic acid.
- The gp91phox enzyme plays a critical role in this process.
- This study provides the first evidence for arachidonic acid-mediated gp91phox activation in platelet CD40L expression.
