Elutriation of human alveolar macrophages: influence on cell surface receptor expression

Centrifugal elutriation has turned out to be a quick and easy to handle method to separate alveolar macrophages with high purity in bronchoalveolar lavage fluid. However, less is known about the influence of elutriation on the expression of cell surface receptors and cell function. We investigated whether the elutriation procedure or different temperatures affect the expression of some surface receptors. These were selected to reflect different aspects of cell function such as phagocytosis (Fc gamma-receptor), antigen presentation (HLA-DR) and proliferation (transferrin receptor). We conclude that the centrifugal elutriation procedure has no influence on the expression of these functional receptors on resting alveolar macrophages. Heat stimulation, however, increased the expression of HLA-DR and the transferrin receptors. Summarizing, when working with alveolar cells at +4 degrees C elutriation is a quick method which yields a high purity of macrophages that are phenotypically unaltered.