title: Chemotactic responses by macrophages to a directional source of a cytokine delivered by a micropipette.
abstract: Macrophages, which are organized throughout every tissue, represent a key component of the immune system and the recruitment of macrophages to specific sites is important in normal host defense. However, when inappropriately recruited macrophages may damage or destroy healthy tissue; this is seen in several autoimmune diseases such as arthritis. Many cytokines, including CSF-1 and chemokines, are often upregulated in inflamed tissues and can induce the directional migration of macrophages towards the highest concentration of the cytokine in a process called chemotaxis. Chemokines were first described as chemoattractant cytokines synthesized at sites of inflammation that stimulate the directional migration of leukocytes and mediate inflammation. Whereas specific receptors for chemoattractants reside over the entire cell surface, macrophages can detect very shallow chemotactic gradients leading to spatially defined responses to the chemoattractant such as the extension of directed protrusions leading to cell migration. In this chapter we describe a method for the localized delivery of chemoattractants via a micropipette needle to macrophages in culture followed by methods for imaging and an outline of quantifying macrophage responses.
authors.affiliation: Office of Collaborative Science & Skirball Institute of Biomolecular Medicine, New York University Langone Medical Center, New York, NY, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Cammer
authors.forename: Dianne
authors.initials: D
authors.lastname: Cox
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D058948:Cell Tracking / Q000379:methods; D002478:Cells, Cultured; D054428:Chemokine CX3CL1 / Q000494:pharmacology; D002630:Chemotactic Factors / Q000494:pharmacology; D002634:Chemotaxis, Leukocyte / Q000276:immunology*; D005456:Fluorescent Dyes; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008845:Microinjections; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction; D059010:Single-Cell Analysis / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D054428:Chemokine CX3CL1; D002630:Chemotactic Factors; C515539:Cx3cl1 protein, mouse; D005456:Fluorescent Dyes; D011994:Recombinant Proteins; D016173:Macrophage Colony-Stimulating Factor