Transcriptional profiling of immortalized LECs (imLECs)

In contrast to the migration of leukocytes from blood vessels into tissues, and the involvement of adhesion molecules and chemokines in this process, the migration of leukocytes from the tissue into lymphatic vessels is much less well understood. This can, in part be explained by the fact that murine lymphatic endothelial cells (LECs) have proven particularly hard to isolate and propagate in culture. Hence, it has been difficult to establish suitable models to study this process in vitro. Combining magnetic bead-based purification and fluorescence-activated cell sorting (FACS), we have isolated LECs (immorto-LECs) from the skin of mice which express a temperature-sensitive SV40 large T antigen (H-2Kb-tsA58 mice; ImmortoMice) in all cell types under the control of the MHC-class-I-promotor, H-2Kb. The isolated cells are viable for more than 30 passages when cultured at 33 C, the temperature at which the large T antigen is stably expressed. Furthermore, immorto-LECs tolerate several days of culture at 37 C, but become senescent if continuously cultured at this temperature. All cells stably express endothelial and lymphatic markers like CD31, podoplanin, Prox-1 and VEGFR-3 up to passage 30. When cultured in presence of tumor necrosis factor-alpha (TNF-a), immorto-LECs upregulate adhesion molecules, such as ICAM-1, VCAM-1 and E-selectin, similarly to what has been reported to occur under inflammatory conditions in vivo. Overall, our findings establish immorto-LECs as a useful and handy tool for the in vitro investigation of immune cell transmigration across lymphatic endothelium.

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Vigl B, Aebischer D, Nitschké M, Iolyeva M, Röthlin T, Antsiferova O, Halin C