Expression of high-affinity IgE receptor (Fc epsilon RI) on human alveolar macrophages from atopic and non-atopic patients

The expression of high-affinity IgE receptor (Fc epsilon RI) on alveolar macrophages was examined in order to determine the association of alveolar macrophages with IgE-dependent inflammation. Immunostaining showed that a 15-1 monoclonal antibody against Fc epsilon RI alpha chain reacted with alveolar macrophages from both atopic and non-atopic patients by immunostaining. In addition, preincubation of 15-1 monoclonal antibody specifically blocked monomeric IgE binding to alveolar macrophages. Reverse transcription polymerase chain reaction showed that CD14+ alveolar macrophages expressed Fc epsilon RI alpha, beta and gamma chain mRNA. These results show that alveolar macrophages express Fc epsilon RI and may participate in IgE-dependent inflammation mediated by Fc epsilon RI.