1. Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153, United States
2. Infectious Disease and Immunology Research Institute, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153, United States
3. Department of Biology, Indiana University, Bloomington, Indiana 47405, United States
4. Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia