Evaluation of transduction efficiency in macrophage colony-stimulating factor differentiated human macrophages using HIV-1 based lentiviral vectors

<p>Abstract</p> <p>Background</p> <p>Monocyte-derived macrophages contribute to atherosclerotic plaque formation. Therefore, manipulating macrophage function could have significant therapeutic value. The objective of this study was to determine transduction efficiency of two HIV-based lentiviral vector configurations as delivery systems for the transduction of primary human blood monocyte-derived macrophages.</p> <p>Results</p> <p>Human blood monocytes were transduced using two VSV-G pseudotyped HIV-1 based lentiviral vectors containing EGFP expression driven by either native HIV-LTR (VRX494) or EF1α promoters (VRX1090). Lentiviral vectors were added to cultured macrophages at different times and multiplicities of infection (MOI). Transduction efficiency was assessed using fluorescence microscopy and flow cytometry. Macrophages transduced between 2 and 120 hours after culturing showed the highest transduction efficiency at 2-hours transduction time. Subsequently, cells were transduced 2 hours after culturing at various vector concentrations (MOIs of 5, 10, 25 and 50) to determine the amount of lentiviral vector particles required to maximally transduce human monocyte-derived macrophages. On day 7, all transduced cultures showed EGFP-positive cells by microscopy. Flow cytometric analysis showed with all MOIs a peak shift corresponding to the presence of EGFP-positive cells. For VRX494, transduction efficiency was maximal at an MOI of 25 to 50 and ranged between 58 and 67%. For VRX1090, transduction efficiency was maximal at an MOI of 10 and ranged between 80 and 90%. Thus, transductions performed with VRX1090 showed a higher number of EGFP-positive cells than VRX494.</p> <p>Conclusions</p> <p>This report shows that VSV-G pseudotyped HIV-based lentiviral vectors can efficiently transduce human blood monocyte-derived macrophages early during differentiation using low particle numbers that do not interfere with differentiation of monocytes into macrophages.</p

Spectroscopic characterization of Er,Yb:Y2Ti2O7 phosphor for latent fingerprint detection

Er3+ doped, Yb3+ doped, and Er3+/Yb3+ co-doped Y2Ti2O7 phosphors with various concentrations of Er3+ (12–20%), Yb3+ (1-10 at%), and Er3+Yb3+ (1%, and 1,2,3%, respectively) were prepared by solid-state reaction. The phase structure and purity of all prepared phosphors were studied by X-ray diffraction analysis followed by measurement of the hydrodynamic diameter of each sample by Dynamic light scattering. The formation of the pyrochlore structure was confirmed by the observation of relative vibrations by Fourier Transform Infrared Spectroscopy. Moreover, photoluminescence spectra of different co-doped Y2Ti2O7 compounds are presented to check the energy transfer processes of Er3+ and Yb3+ ions. Finally, phosphors were used for the detection of latent fingermarks on various surfaces and a fingerprint minutia extraction algorithm was used for the analysis of extracted minutiae. The analyses confirm that the co-doped phosphors can be useful for the visualization of latent fingerprints once a good detection of their minutiae is obtained