Assessment of chemokinetic behavior of inflammatory lung macrophages in a linear under-agarose assay

Migration of cells in response to a chemoattractant gradient is influenced by directed migration (chemotaxis) and stimulated random motility (chemokinesis). The present study quantitated the chemokinetic motility of normal and inflammatory lung macrophages by performing the linear under-agarose assay in the presence of uniform concentrations of chemoattractant. Under these conditions, cell motility can be likened to a molecular diffusion process. Mathematical analyses which describe molecular diffusion were then applied, allowing the quantitation of the parameter, mu, the cellular equivalent to the molecular diffusivity constant. Determination of changes in mu as a function of chemoattractant concentration revealed that the chemokinetic motility of alveolar macrophages recovered during the early stages of acute pulmonary inflammation was greater than that of normal alveolar macrophages and macrophages recovered later in the inflammatory response. The correlation of differences in macrophage chemokinesis with macrophage maturation and the relevance of these differences to macrophage accumulation during inflammation are discussed.