Serial immunostaining showed that ∼43% of these cells were CD103+ and that ∼63% were CD11c+ (Table 1; Fig. 2C); some were also CD25+ and/or CD86+ (Fig. 2D). The mean Sirolimus survival time of the Irr(−) and Irr(+) groups were 10.3 ± 1.6 (n = 9) and 8.8 ± 1.0 days (n = 4) after LT, respectively (Fig. 5A), indicating that irradiation enhanced rejection slightly, but not significantly. The ratio of the sinusoidal area to the total surface area was significantly higher in the Irr(+) group than in the Irr(−) group’s on day 5, but became

comparable by day 7 (Fig. 5B). The CD8+ T-cell responses were comparable in the Irr(+) and Irr(−) groups, as shown by the kinetics of BrdU+CD8β+ cell numbers in the graft portal and sinusoidal areas (Fig. 5C-F). In both the Irr(−) and Irr(+) groups, donor MHCII+ DC-like cells were observed in clusters with BrdU+ cells that were found in the graft portal and hepatic vein areas on days 2-4 after LT (Fig. 6A). FACS analysis to detect nonparenchymal cells on day 3 after LT showed that the sessile donor DCs were mainly in the CD172a+CD11b+

population in both groups and that they expressed similar levels of CD25 and CD86 (Fig. 6B-D). Immunostained serial sections showed that of these donor MHCII+ cluster-forming cells, ∼65% were CD103+ and ∼82% were CD11c+ (Table 1; Fig. 6E,F). Furthermore, some also coexpressed CD86 (Fig. 6F). Cytosmears of FACS-sorted selleck chemical liver DC subsets showed their DC cytology (Fig. 7A). The positive stimulator control of the donor splenic DCs induced a dose-dependent proliferation

of responder T cells. The CD172a+CD11b+ DCs (3 × 103/well) that were isolated from the donor liver with or without irradiation and from the irradiated donor hepatic lymph induced high proliferation comparable to the control splenic DCs (3 × 103/well) (Fig. 7B). In contrast, CD172a−CD11b+ DCs isolated from the nonirradiated donor liver (3 × 103/well) showed a lower this website stimulation index (Fig. 7B). The CD172a+CD11b+ DCs formed huge clusters in vitro that were larger than clusters formed by the CD172a−CD11b+ DCs (Fig. 7C). The number of BrdU+FoxP3+ regulatory T cells was suppressed slightly on day 2 in both the spleen and graft portal areas in the Irr(+) group, compared to the Irr(−) group (Supporting Fig. 3A,B); however, suppression was not significantly different over the entire examination period. The total number of FoxP3+ cells in the portal areas was also comparable (Supporting Fig. 3C). The 35,129-element oligonucleotide microarray of graft tissues used to analyze the Irr(+) group identified 117 up-regulated and 79 down-regulated genes on day 2 and 95 up-regulated and 79 down-regulated genes on day 3 after LT, compared to the Irr(−) group. Among these, several genes were related to immune responses.