Dendritic cell migration in different micropore filter assays

Dendritic cells (DC) are highly motile and have been shown to migrate in vi tro or in vivo towards various chemoattractants. Micropore filter methods w ith polycarbonate tilters are generally used in these in vitro experiments. Among others, the main drawback of these filters is their thickness, which does not allow any assessment of effects of absolute concentration compare d to gradients, The aim of this study was to establish a chemotaxis assay f or dendritic cells using nitrocellulose filters, which can be adapted for c heckerboard studies to distinguish between chemokinesis and chemotaxis. Imm ature DC were generated by culture of peripheral blood mononuclear cells us ing granulocyte-macrophage colony-stimulating factor and interleukin-4. We tested cell migration into nitrocellulose in a Boyden microchemotaxis chamb er (leading front assay) and compared this method to the commonly used poly carbonate filter technique. Dendritic cells migrated well into nitrocellulo se towards gradients of formyl peptide, complement fragment 5a, and monocyt e chemotactic protein-3. The nitrocellulose method appeared to be more sens itive as compared to experiments testing migration across polycarbonate fil ters. Subsequent checkerboard analyses confirmed chemotactic activities of formyl peptide and complement fragment 5a. However, depending on the assay system, chemotaxis in polycarbonate filters but chemokinesis in nitrocellul ose filters were observed for monocyte chemotactic protein-3. Measurement o f DC migration in a cellulose nitrate micropore filter assay is more sensit ive than the commonly used polycarbonate method and can be adapted for chec kerboard analyses. (C) 2000 Elsevier Science B.V. All rights reserved.