1. Research Center for Biomedicine, Department of Medical Microbiology and Immunology, University of Oulu, Oulu, Finland
2. Department of Virology, University of Turku, Turku, Finland
3. Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu, Finland
4. Drug Research Doctoral Programme, University of Turku, Turku, Finland
5. Department of Microbiology, NYU School of Medicine, New York, NY, USA