RESUMEN
Objective:To study if embryonic stem cell derived dendritic cells(esDCs) could induce transplant tolerance to syngeneic neural progenitor cells ( NPCs) in ischemic rat brain.Methods:Neural progenitor cells ( NPCs) were differentiated from 129/svj pCX-eGFP ES-D3 embryonic stem cells and dendritic cells were directly differentiated from 129/svj ES-D3 respectively.All of SD rats were accepted MCAo surgery and subdivided in two groups based on pretreatment with or without esDCs through tail vein injection 1 week after MCAo.pCX-eGFP NPCs were then injected into the lateral ventricle of animals 2 weeks after MCAo.A proliferation assay of lymphocytes dissociated from cervical lymph nodes by MTT method,counting of the survival of the grafted cells, histological evaluation of CD4,CD8 and ED1 positive cells in brain and detection of mRNA level of IL-10 and IFN-γin ischemic lesions by reverse transcriptase-polymerase chain reaction(RT-PCR) were performed 2 weeks after graft (4 weeks after MCAo).Results:Pre-treatment with esDCs decreased CD4 positive cells infiltration (134.7 ±36.2 vs.198.8 ±59.6,P0.05).There was also no difference in lymphocytes proliferation (PI,1.245 ±0.211 vs.1.331 ±0.235) or mRNA expression level of IL-10 ( 1.147 ±0.260 vs.1.264 ±0.119 ) and IFN-γ( 1.697 ±0.273 vs.1.829 ±0.250 ) between two groups ( P>0.05).Conclusion:The results indicate that pretreatment with esDCs may prolong syngeneic NPCs survival though reducing CD4 positive cells reaction in ischemic striatum,which provides some evidence for the tolerogenic function of esDCs.However,there was lack of evidence for cytokine-dependent routine involving in this mode and further investigation was needed to make certain the cardinal principle.
RESUMEN
The γc cytokines play an important role in proliferation and survival of T cells. Blocking the γc signals can cause the activated donor-reactive T cells losing the ability to proliferate, and getting into apoptosis pathway, which contributes to induction of the peripheral tolerance. In this study, we induced the transplant tolerance through blocking the γc in combination with donor-specific trans-fusion (DST) in the cardiac transplantation. Following DST, on the day 2, 4 and 6, C57BL/6 recipients received anti-γc monoclonal antibodies (mAbs) injection, and those in control group were not given anti-γc mAbs. On the day 7, Balb/c cardiac allografts were transplanted. All recipients in experimental group accepted cardiac allografis over 30 days, and two of them accepted allografis without rejection until sacrifice on the 120 day. Animals only receiving DST rejected gratis within 5 days, and the mice receiving cardiac transplantation alone rejected gratis within 9 days. Our study showed that blockade of γc signaling combined with DST significantly prolonged allografi survival, which was probably associated with inhibition of antigen-specific T-cell proliferation and induction of apoptosis.
RESUMEN
One of the mechanisms for generation of tolerance involves immature dendritic cells (DCs) and a subpopulation of regulatory CD4+ CD25+ T lymphocytes (T REG). The purpose of this work was to analyze how Cyclosporine A (CsA), a widely used immunosuppressive drug, may affect T REG proliferation. Purified and activated murine DCs obtained from bone marrow precursors differentiated with rGMCSF were co-cultured with purified CFSE-labeled T REG from OTII mice, and their phenotype and proliferation analyzed by flow cytometry. Our data indicate that DCs differentiated in the presence of CsA show an altered phenotype, with a lower expression of MHC-II and a lower activating capacity. Additionally, these CsA-treated DCs show decreased production of IL-2 and IL-12 and increased IL-10 secretion when stimulated with LPS, indicating an effect on the polarization of the immune response. Interestingly, CsA-treated DCs show an anti-tolerogenic effect since they reduce the proliferation of T REG cells from 72 to 47 percent. Further inhibition to a 24 percent of T REG proliferation was obtained as a direct effect of CsA on T REG. In conclusion, the anti-tolerogenic effect of CsA should be considered in the planning of immunosuppression in the context of clinical transplantation.