• Evaluation of the inflammatory potential of implant materials in a mouse model by bioluminescent imaging of intravenously injected bone marrow cells.

      Rais, Bushra; Köster, Mario; Rahim, Muhammad Imran; Pils, Marina; Seitz, Jan-Marten; Hauser, Hansjörg; Wirth, Dagmar; Mueller, Peter P; Helmholtz Centre for infection research, Inhoffenstr. 7,38124 Braunschweig, Germany. (2016-09)
      To evaluate the inflammatory potential of implants a bioluminescent imaging assay was developed using luciferase-expressing bone marrow cells that were injected into the blood circulation of wild-type mice. After subcutaneous implantation of titanium discs as an example for a clinically established biocompatible material, the luminosity was modest. Similarly, low luminosity signals were generated by pure magnesium implants that were used to represent metallic alloys that are presently under investigation as novel degradable implant materials. Increased luminosity was observed in response to degradable polymeric PLGA implants. Surgical wounds induced a basic luminescent response even in the absence of an implant. However, the material-independent response to injury could be minimized using injectable microparticle suspensions. In parallel with the resorption of biodegradable microparticles, the signal induced by PLGA declined faster when compared to non-degradable polystyrene suspensions. By using an interferon type I inducible Mx2 promoter construct to drive luciferase gene expression, the highest luminosity was observed in response to bacteria, indicating that the system could also be employed to monitor implant infections. Overall, labeled bone marrow cells yielded specific, well-defined localized signals that correlated with the inflammatory responses to implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2149-2158, 2016.
    • Screening and characterization of molecules that modulate the biological activity of IFNs-I.

      Bürgi, Milagros; Zapol'skii, Viktor A; Hinkelmann, Bettina; Köster, Mario; Kaufmann, Dieter E; Sasse, Florenz; Hauser, Hansjörg; Etcheverrigaray, Marina; Kratje, Ricardo; Bollati-Fogolín, Mariela; et al. (2016-09-10)
      Type I Interferons (IFNs-I) are species-specific glycoproteins which play an important role as primary defence against viral infections and that can also modulate the adaptive immune system. In some autoimmune diseases, interferons (IFNs) are over-produced. IFNs are widely used as biopharmaceuticals for a variety of cancer indications, chronic viral diseases, and for their immuno-modulatory action in patients with multiple sclerosis; therefore, increasing their therapeutic efficiency and decreasing their side effects is of high clinical value. In this sense, it is interesting to find molecules that can modulate the activity of IFNs. In order to achieve that, it was necessary to establish a simple, fast and robust assay to analyze numerous compounds simultaneously. We developed four reporter gene assays (RGAs) to identify IFN activity modulator compounds by using WISH-Mx2/EGFP, HeLa-Mx2/EGFP, A549-Mx2/EGFP, and HEp2-Mx2/EGFP reporter cell lines (RCLs). All of them present a Z' factor higher than 0.7. By using these RGAs, natural and synthetic compounds were analyzed simultaneously. A total of 442 compounds were studied by the Low Throughput Screening (LTS) assay using the four RCLs to discriminate between their inhibitory or enhancing effects on IFN activity. Some of them were characterized and 15 leads were identified. Finally, one promising candidate with enhancing effect on IFN-α/-β activity and five compounds with inhibitory effect were described.