An observation time of 1?min is suitable to study the initial interactions, e

An observation time of 1?min is suitable to study the initial interactions, e.g., capture and rolling, of T cells with the BBB. T cells) and anti-endoglin (red, blood vessels) were excited at 780?nm. A time-lapse sequence of a 400?m??400?m scan field at a depth of 47C91?m and 12 activated CD4+ T cells from 2D2-GFP-mice were injected a carotid catheter before 2P-IVM imaging. Contrast enhancement of blood vessels was achieved by injection of Texas Red-dextran (MW?=?70,000). GFP (green, CD4+ T cells) and Texas Red were excited at 780?nm. A time-lapse sequence of a 150?m??150?m scan field at a depth of 59C76?m and 11 activated 2D2 CD4+ T-cells labeled with fluorescent CellTracker CMAC were systemically injected the carotid artery catheter into a surgically prepared mouse at the onset of EAE. In the regions of interest, one transferred CD4+ T cell was observed to crawl along the direction of blood flow until 4?min and 20?s of recording. At this time, the T cell changed the direction of crawling against the blood flow until minute 12 of the recording. At this time point, the observed T cell again changed the direction of crawling along the direction of blood flow and continued to crawl to the end of 20?min of recording. A time-lapse sequence of a 200?m??200?m scan field at a depth of 79C100?m and 8 MSDC-0602 activated 2D2 GFP CD4+ T cells and 2D2 CD4+ T cells labeled with fluorescent CellTracker CMAC were systemically MSDC-0602 injected the carotid artery catheter into a surgically prepared EAE mouse at the onset of disease. A CMAC labeled T cell (blue cell) is seen to crawl against the direction of blood flow for the entire 20?min of recording. A GFP+ T cell is seen to crawl against the direction of blood flow until 3?min of the recording when it detached and re-entered circulation. Another GFP+ T cell (at time point of 13?min) and two additional CMAC labeled T cells (at time points of 8?min:40?s and 9?min:40?s) can be observed to transiently arrest on and crawl along the vascular wall and to rapidly re-enter blood circulation. A time-lapse sequence of a 300?m??300?m scan field at a depth of 52C115?m and 16 activated CD4+ T cells from 2D2-GFP-mice and 2D2 CD4+ T cells MSDC-0602 labeled with fluorescent CellTracker CMAC were systemically injected a carotid catheter before 2P-IVM imaging. A time-lapse sequence of a 400?m??400?m scan field at a depth of 47C91?m and 12 activated CD4+ T cells from 2D2-GFP-mice were systemically injected a carotid catheter before 2P-IVM imaging. During the recording of 15?min, two CD4+ T cells undergoing diapedesis across cervical spinal cord post-capillary venules can be observed. A time-lapse sequence of a 300?m??300?m at a depth of 60C112?m and 14 activated neuroantigen specific CD4+ T cells into syngeneic susceptible recipients. These encephalitogenic CD4+ T cells have acquired the molecular MSDC-0602 keys allowing them to engage the cell ITGA8 adhesion and signaling molecules on the BBB allowing them to cross this barrier in a multistep process. Having crossed the BBB, these T cells become reactivated after recognition of their cognate antigen on antigen-presenting cells in the context of major histocompatibility class II (MHC class II) molecules and initiate an inflammatory cascade leading to inflammation, demyelination, and neurodegeneration (1C3). Several research groups have employed real-time epifluorescence intravital microscopy (IVM) using a cranial window model to study the interaction of T cells within superficial brain microvessels during EAE. These studies demonstrated that P-selectin glycoprotein ligand-1 (PSGL-1) and 4-integrins are important for T-cell rolling in inflamed leptomeningeal brain vessels, while lymphocyte function associated antigen-1 and 4-integrins mediate T cell arrest (4, 5). These findings were confirmed by others who demonstrated that T-cell rolling and arrest in the superficial brain vessels exposed in the cranial window preparation are mediated by endothelial P-selectin and 4-integrins on T cells, respectively (6, 7). We have MSDC-0602 pioneered preparation of a cervical spinal cord window in mice allowing to observe the interaction of activated encephalitogenic T cells with cervical spinal cord.