Isolation and culture of human airway smooth muscle cells

Airway smooth muscle (ASM) cells may be considered an important modulator of airway inflammatory responses, since they synthesize cytokines, chemokines, growth factors and metalloproteinases as well as support the adhesion of activated T lymphocytes. The study of the cellular and molecular mechanisms of inflammatory mediators on airway smooth muscle was initially hampered by the inability to prepare pure populations of cells that retained the phenotypic characteristics of the differentiated cell. The study of smooth muscle cell immunobiology has been facilitated by the development of a technique for isolating and maintaining nontransformed human airway smooth muscle cells (1). These cells retain the physiologic responsiveness to a wide range of stimuli including inflammatory mediators, growth factors, contractile agonists and immune receptor crosslinking. Studies have shown that, although there is some phenotypic modulation, these cultured cells are stable over many population doublings and express smooth muscle cell-specific markers such as myosin heavy chain, myosin light chain kinase, α-actin, caldesmon, and SM22α . In addition, the synthetic function of these cells appears to be comparable to those studied in vivo. Here, we describe in detail our method for the isolation of human airway smooth muscle cells.