After 4 hr the numbers of cells migrated to the bottom wells or not were determined by flow cytometric analysis of the content of the bottom wells and the inserts, respectively, on a FACSCalibur (BD Biosciences). The migration rate was calculated by division of the number of cells in the bottom well by the total number of cells present in the insert and in the bottom well. As a control, the number of cells added to the inserts was determined by flow cytometric analysis on

a FACSCalibur (BD Biosciences). 5 × 106 BMDCs d8 were loaded with 2 µM fluo-3 AM with an excitation maximum at 506 nm and an emission maximum at 526 nm (Molecular Probes, Leiden, R788 in vitro the Netherlands) in supplemented RPMI 1640 medium for 20 min. After washing for two times with fresh medium in supplemented RPMI 1640 medium were seeded at a density

of 1 × 106 BMDCs in uncoated six-well plates and stimulated or not with 500 ng/mL LPS up GSK 3 inhibitor to 4 hr. At the indicated time points 1.25 × 105 cells were harvested and 2000 cells each were analyzed for the mean Ca2+-dependent fluo-3 AM fluorescence intensity (excitation wave length 488 nm, detection wave length 530 nm) on an LSRFortessa™ cytometer using FACSDiva™ software version 6.1.3 (both from BD Biosciences). 1 × 106 BMDCs d8 in supplemented RPMI 1640 medium were seeded in uncoated 24-well plates (Greiner Bio-One) and stimulated or not with 500 ng/mL LPS (Calbiochem) for 4 hr. Thereafter, cells were harvested, centrifuged (400g, 5 min), and the pellet was resuspended in 50 µL PBS. After addition of 0.5 µg biotin-conjugated anti-mouse CCR7 clone 4B12 (eBioscience,

Frankfurt, Germany) and 0.2 µg APC-labeled anti-mouse CD11c (HL3) (BD Pharmingen 550261, Heidelberg, Germany) antibodies cells were incubated for 30 min on ice. After washing with PBS cells were resuspended in 50 µL PBS and incubated with 0.5 µg Streptavidin-PE antibodies (BD Pharmingen 554061) for 30 min on ice to detect binding of the biotin-conjugated CCR7 antibodies. After washing with PBS cells were analyzed by an LSRFortessa™ cytometer using FACSDiva™ software version 6.1.3. The expression CCR7 on BMDCs was determined by gating on double-positive (CD11c+/CCR7+) cells. The unpaired two-tailed Ureohydrolase Student’s t-test was used to evaluate differences in means between two groups. P-values were considered statistically significant if *P < 0.05, **P <0.01, or ***P < 0.001. LPS signaling can induce maturation and migration of DCs [7]. Additionally, it has been described that cell swelling is essential for N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced migration of human polymorphonuclear leukocytes [12]. Additionally, swelling of DCs has been observed after treatment with LPS for 4 hr [13]. Hence, in order to analyze the role of TLR4 signaling in LPS-induced cell volume changes, we analyzed cell volume changes of immature WT and TLR4−/− BMDCs at different time points after addition of LPS.