A Comparison of FcεRI-Mediated RANTES Release from Human Platelets between Allergic Patients and Healthy Individuals

Abstract

Background: Recently some studies have suggested that human platelets may play an important role in allergic inflammation through the high affinity IgE receptor (FcΕRI), the low affinity IgE receptor (FcΕRII/CD23) and the low affinity IgG receptor (FcγRIIA/CD32) expressed on the cell surface. We reported that human platelets via the FcΕRI induced the release of the chemical mediator serotonin and the chemokine RANTES (regulated upon activation, normal T expressed and presumably secreted), but the biological implication of human platelets in type I allergy has not yet been understood clearly. Methods: We compared the levels of RANTES release from platelets obtained from allergic patients and healthy individuals, stimulated with monoclonal antibody (Ab) to human FcΕRI α-chain, or human myeloma IgE and anti-human IgE Ab. Results: We confirmed that the level of RANTES release from platelets of allergic patients stimulated with human IgE and anti-human IgE was significantly higher than that of healthy individuals. Conclusions: We demonstrated that the surface expression levels of FcΕRI on the platelets from allergic patients and healthy individuals were not significantly different, but that the platelets of allergic patients were more activated by the IgE-FcΕRI pathway than those of healthy individuals. Taken together, these results suggest a novel and important role for human platelets in perpetuating allergic inflammation through the IgE and FcΕRI.