Supramolecular Organization Predicts Protein Nanoparticle Delivery to Neutrophils for Acute Lung Inflammation Diagnosis and Treatment

Jacob W. Myerson; Priyal N. Patel; Nahal Habibi; Landis R. Walsh; Yi-Wei Lee; David C. Luther; Laura T. Ferguson; Michael H. Zaleski; Marco E. Zamora; Oscar A. Marcos-Contreras; Patrick M. Glassman; Ian Johnston; Elizabeth D. Hood; Tea Shuvaeva; Jason V. Gregory; Raisa Y. Kiseleva; Jia Nong; Kathryn M. Rubey; Colin F. Greineder; Samir Mitragotri; George S. Worthen; Vincent M. Rotello; Joerg Lahann; Vladimir R. Muzykantov; Jacob S. Brenner

To quantify the increase in pulmonary marginated neutrophils after inflammatory lung injury, radiolabeled clone 1A8 anti-Ly6G antibody (specific for mouse neutrophils) was administered intravenously (IV) to determine the location and concentration of neutrophils in mice. IV injection of LPS subjected mice to a model of mild ARDS. Accumulation of anti-Ly6G antibody in the lungs was dramatically affected by IV LPS, with 20.81% of injected antibody adhering in LPS-injured lungs, compared to 2.82% of injected antibody in naïve control lungs ( Figure 1B) . Agreeing with previous studies addressing the role of neutrophils in systemic inflammation, biodistributions of anti-Ly6G antibody indicated that systemic LPS injury profoundly increased the concentration of neutrophils in the lungs. 6, 10, 14, 18 Single cell suspensions prepared from mouse lungs were probed by flow cytometry to further characterize pulmonary neutrophils in naïve mice and in mice following LPS-induced inflammation. To identify intravascular populations of leukocytes, mice received IV fluorescent CD45 antibody five minutes prior to sacrifice. Single cell suspensions prepared from IV CD45-stained lungs were then stained with anti-Ly6G antibody to identify neutrophils. A second stain of single cell suspensions with CD45 antibody indicated the total population of leukocytes in the lungs, distinct from the intravascular population indicated by IV CD45.