Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium. filip.bielejec@rega.kuleuven.be.|Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium. filip.bielejec@rega.kuleuven.be.|Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium. filip.bielejec@rega.kuleuven.be.|Department of Neurobiology and Anatomy, University of Texas Health Science Center at Houston, Houston, Texas, USA. yin.liu@uth.tmc.edu.