title: Use of folate-conjugated imaging agents to target alternatively activated macrophages in a murine model of asthma.
abstract: Pro-inflammatory macrophages play a prominent role in such autoimmune diseases as rheumatoid arthritis, Crohn's disease, psoriasis, sarcoidosis, and atherosclerosis. Because pro-inflammatory macrophages have also been shown to overexpress a receptor for the vitamin folic acid (i.e., folate receptor beta; FR-β), folate-linked drugs have been explored for use in imaging and treatment of these same diseases. To determine whether allergic inflammatory disorders might be similarly targeted with folate-linked drugs, we have examined the characteristics of macrophages that are prominent in the pathogenesis of asthma. We report here that macrophages from the lungs of mice with experimental allergic asthma express FR-β. We further document that these FR-β(+) macrophages coexpress markers of alternatively activated (M2-type) macrophages, including the mannose receptor and arginase-1. Finally, we demonstrate that folate-conjugated fluorescent dyes and radioimaging agents can be specifically targeted to these asthmatic lung macrophages, with little uptake by macrophages present in healthy lung tissue. These data suggest strategies for the development of novel diagnostic agents for the imaging of asthma and other diseases involving alternatively activated macrophages.
authors: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
authors: Jiayin
authors: J
authors: Shen
authors: Venkatesh
authors: V
authors: Chelvam
authors: Gregory
authors: G
authors: Cresswell
authors: Philip S
authors: PS
authors: Low
mesh_terms: D000818:Animals; D001119:Arginase / Q000378:metabolism; D001249:Asthma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000276:immunology*; D003952:Diagnostic Imaging / Q000379:methods; D004195:Disease Models, Animal; D005260:Female; D005456:Fluorescent Dyes; D058976:Folate Receptor 2 / Q000378:metabolism; D005492:Folic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D037181:Lectins, C-Type / Q000378:metabolism; D008168:Lung / Q000000981:diagnostic imaging / Q000276:immunology / Q000378:metabolism; D008262:Macrophage Activation; D008264:Macrophages / Q000000981:diagnostic imaging / Q000276:immunology / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009842:Oligopeptides; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D011956:Receptors, Cell Surface / Q000378:metabolism; D013667:Technetium
chemical_list: C473829:EC20 folate peptide; D005456:Fluorescent Dyes; D058976:Folate Receptor 2; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009842:Oligopeptides; D019275:Radiopharmaceuticals; D011956:Receptors, Cell Surface; D013667:Technetium; D005492:Folic Acid; C544448:Arg1 protein, mouse; D001119:Arginase