Monocyte behaviour and tissue transglutaminase expression during experimental autoimmune encephalomyelitis in transgenic

Leukocyte infiltration into the central nervous system (CNS) is a key pathological feature in multiple scle- rosis (MS) and the MS animal model experimental autoim- mune encephalomyelitis (EAE). Recently, preventing leu- kocyte influx into the CNS of MS patients is the main target of MS therapies and insight into cell behaviour in the circu- lation is needed for further elucidation of such therapies. In this study, we aimed at in vivo visualization of monocytes in a time-dependent manner during EAE. Using intravital two-photon microscopy (IVM), we imaged CX3CR1 gfp/ gfp mice during EAE, visualizing CX3CR1-GFP + mono- cytes and their dynamics in the spinal cord vasculature. Our observations showed that intraluminal crawling of CX3CR1-GFP + monocytes increased even before the clinical onset of EAE due to immunization of the animals. Furthermore, intraluminal crawling remained elevated dur- ing ongoing clinical disease. Besides, the displacement of these cells was larger during the peak of EAE compared to the control animals. In addition, we showed that the