1. Department of Microbiology and Immunology, Midwestern University, Downers Grove, IL 60515, USA
2. Department of Microbiology and Immunology, University of Illinois at Chicago, 1855 W. Taylor Street, LIERI Building, Chicago, IL 60612, USA
3. Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor Street, LIERI Building, Chicago, IL 60612, USA