Volume 106, Issue 3, Pages 598-609 (February 2014) Effects of Lipid Interactions on Model Vesicle Engulfment by Alveolar Macrophages  Matthew J. Justice, Daniela N. Petrusca, Adriana L. Rogozea, Justin A. Williams, Kelly S. Schweitzer, Irina Petrache, Stephen R. Wassall, Horia I. Petrache  Biophysical Journal  Volume 106, Issue 3, Pages 598-609 (February 2014) DOI: 10.1016/j.bpj.2013.12.036 Copyright © 2014 Biophysical Society Terms and Conditions

Figure 1 Chemical stuctures of model lipid membranes POPC, POPS, Cer6:0, and Cer18:1 used in this study. Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 2 (A) SAXS of DOPS/DOPC mixtures at 30°C in 200 mM NaCl solutions. Scattering intensity is plotted versus scattering angle 2θ and is presented in arbitrary units with curves offset vertically for clarity. Vertical dashed lines indicate the position of scattering peaks for the uppermost curve. (B) Plot of lamellar repeat spacings versus PS/PC molar ratio in DOPS/DOPC (squares) and POPS/POPC mixtures (circles). Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 3 Optical microscopy images of fluorescently labeled POPC MLVs (upper) and POPS ULVs (lower) in 200 mM NaCl, pH 7.5, at room temperature. Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 4 X-ray scattering of Cer/POPS/POPC mixtures at 30°C. Scattering curves have been shifted vertically for clarity. The uppermost curve shows pure POPC and the lower curves show PS/PC mixtures with molar ratios 1:20 (A) and 1:10 (B). Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 5 2H NMR spectra of 50 wt % aqueous dispersions of POPC-d31 in POPC (A), POPS-d31 in POPS (B), POPC-d31 in POPS/POPC (1:20) (C), and POPS-d31 in POPS/POPC (1:20) (D). Samples were prepared in phosphate buffer at pH 7.5 and spectra were acquired at 30°C. Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 6 Smoothed profile of order parameter SCD versus position along the sn-1 chain at 30°C for (A) POPC-d31 in POPC (solid line), Cer6:0/POPC (1:10) (open circles), and Cer18:1/POPC (1:10) (open squares); (B) POPS-d31 in POPS (solid line), Cer6:0/POPS (1:10) (open circles), and Cer18:1/POPS (1:10) (open squares); (C) POPC-d31 in POPS/POPC (1:20) (solid line), Cer6:0/POPS/POPC (1:1:20) (open circles), and Cer18:1/POPS/POPC (1:1:20) (open squares); and (D) POPS-d31 in POPS/POPC (1:20) (solid line), Cer6:0/POPS/POPC (1:1:20) (open circles), and Cer18:1/POPS/POPC (1:1:20 mol) (open squares). Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 7 Two different fluorescence microscope images of a single rat AM cell (red, cytoplasm autofluorescence; blue, nucleus) engulfing several fluorescently labeled POPS/POPC lipid vesicles (green). Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions

Figure 8 (A) Engulfment of POPS/POPC vesicles by macrophages as a function of PS/PC ratio. (B) Engulfment of 1:1 POPS/POPC vesicles as a function of added Cer to target vesicles as indicated on the horizontal axis. Open bars represent measurements with native macrophages and solid bars measurements with macrophages pretreated with Cer6:0. Biophysical Journal 2014 106, 598-609DOI: (10.1016/j.bpj.2013.12.036) Copyright © 2014 Biophysical Society Terms and Conditions