Rapamycin combined with donor bone marrow-derived immature dendritic cells induces mouse skin allograft tolerance / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the synergic effects of rapamycin and donor bone marrow-derived immature dendritic cells (DCs) in inducing skin allograft tolerance in mice.</p><p><b>METHODS</b>The recipient BALB/c mice receiving transplantation of skin allograft from C57BL/6 mice were divided into control group (without perioperative treatments), rapamycin group (receiving rapamycin at 1 mg.kg(-1).d(-1) by gavage for 7 consecutive 7 days after skin transplantation), immature DC group (receiving an injection of donor bone marrow-derived immature DCs of 2 x 10(6) via tail vein before skin transplantation), combined group (receiving an injection of the DCs of 2 x 10(6) before transplantation and rapamycin at 1 mg.kg(-1).d(-1) for 7 consecutive days after transplantation). The survival time of the skin allograft was observed in each group.</p><p><b>RESULTS</b>The survival time of the skin allograft in the control, rapamycin, immature DC and immature DC +rapamycin groups were 6.9-/+1.9, 12.3-/+3.0, 17.0-/+3.4 and 20.8-/+3.6 days, respectively, showing significant differences among the groups (P<0.05), and SNK test also indicated significant differences between every two groups.</p><p><b>CONCLUSIONS</b>Rapamycin and donor bone marrow-derived immature DCs have synergic effects in inducing skin allograft tolerance in mice.</p>

Culture and identification of mouse myeloid semimature dendritic cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the methods of culturing and identifying mouse myeloid semimature dendritic cell (smDC) in vitro.</p><p><b>METHODS</b>Myeloid monocytes derived from 6-week-old C57 BL/6 mice were cultured in RPMI-1640 medium containing 10% fetal bovine serum, 2 ng/ml recombinant murine granulocyte macrophage-colony stimulating factor (GM-CSF), and 20 ng/ml recombinant murine interleukin (IL)-4 for 9 days. Then cells were incubated with 40 ng/ml tumor necrosis factor-alpha (TNF-alpha) for 24 hours to obtain smDC. Meanwhile, smDC was differentiated into mature dendritic cell (mDC) or immature dendritic cell (iDC) by treatment with 1 micro/m1 lipopolysaccharide (LPS) or without LPS. The morphological features of smDC were assayed by inverted microscopy and scanning electron microscopy. Surface markers such as CD11c, CD4O, CD8O, CD86, and MHC-II were tested by flow cytometry. IL-1beta, IL-6, IL-12, and IL-10 in the supernatant were tested by ELISA. The activation of allogene lymphocyte (BALB/c mice) stimulated by C57BL/6 myeloid smDC in mixed lymphocyte reaction was examined by Cell Counting Kit-8 in vitro.</p><p><b>RESULTS</b>The shape of smDC was round or oval-shaped, and the diameter of smDC was about 15 microm. The length of smDC dendrite was between 5 to 10 microm. smDC, iDC, and mDC all expressed high level of CD11 c. The expressions of MHC-II, CD40, CD80, and CD86 on smDC were higher than those of iDC and lower than those of mDC. IL-1beta, IL-6, and IL-12 secretion of smDC was significantly lower than that of mDC (P < 0.01), and IL-12 was significantly lower than that of iDC (P < 0.05), while no significant difference of IL-1beta and IL-6 secretion was found between smDC and iDC (P > 0.05). Furthermore, IL-10 secretion was not significantly different among these three kinds of DCs (P > 0.05). The effect of allogene lymphocytes activation on smDC was significantly lower than that of mDC and positive control (P < 0.01), but had no significant difference when compared with that of iDC and negative control (P > 0.05).</p><p><b>CONCLUSIONS</b>smDC may be a relatively independent dendritic cell sub-population in terms of function and morphology. It is a feasible way to induce myeloid monocytes to differentiate into smDC using GM-CSF, IL-4, and TNF-alpha in vitro.</p>