Skin Graft Survival Research Articles

Microvascular Integrity Plays a Role in Graft Survival After Skin Transplantation.

Introduction: Every transplanted organ relies on a reliable and sound vascular system. Therefore, our study focused on the investigation if platelet inhibition alone or combined with mTOR-inhibition has a beneficial effect on the microvascular integrity in murine skin grafts. Methods: The skin of fully MHC-mismatched C57 BL/6 (H2(b)) donors was transplanted into CBA Jri (H2(k)) mice. The animals were divided in several groups and according to their group treated with Clopidogrel, Everolimus or both. Grafts were harvested after 8 days and analyzed by immunohistology. For this purpose the frozen sections were tagged with anti-CD31 and anti-C4d, respectively. Results: Untreated allografts displayed in comparison to isografts a reduced amount of CD31 on postoperative day 8 as well as an increase in C4d. All treated animals showed a significant improvement regarding CD31 [1748,78 ± 155,71 (Clopidogrel) / 1702,83 ± 151,13 (Clopidogrel + Everolimus) vs. 479,68 ± 184,17 (control), n=8, p<0,05] and c4d [248,86 ± 54,73 (Clopidogrel) / 324,45 ± 77,31 (Clopidogrel + Everolimus) vs. 772,40 ± 159,72 (control), n=8, p<0,05]. The skin grafts of animals treated with Clopidogrel and Everolimus survived significantly longer than untreated controls [19.2 ± 4.2 d vs. 12.8 ± 2.4, n= 10, p<0.05]. Conclusions: Clopidogrel alone and in combination with Everolimus substantially improved the microvascular integrity and resulted in extended skin graft survival.

Effects of Lymphangiogenesis Blockade On Cell Trafficking, Alloimmunity and Rejection After Skin or Heart Transplantation.

Seminal studies from Billingham and others have demonstrated the key role of afferent lymphatics in the migration of donor passenger leukocytes to the recipient's lymph nodes after skin transplantation. In the present study, we tested the effect of mF4-31C, an anti-VEGFR3 antibody known to alter lymphangiogenesis, on the donor cell trafficking, T cell alloresponse and rejection after placement of skin or heart allografts. First, BALB/c mice were treated with mF4-31C (0.25 mg, i.p. at day 1, 3 and 5 post-Tx) or mF4-31C + MR1 (anti-CD40L mAb) and transplanted with a fully allogeneic B6-GFP skin graft. mF4-31C treatment resulted in an absence of donor passenger leukocytes in the recipient's draining lymph nodes (day 6 post-Tx), a reduction of the direct alloresponse and an abrogation of the indirect alloresponse by T cells but no prolongation of allograft survival (MST 10-12 days). Co-treatment with mF4-31C and MR1 abrogated both direct and indirect T cell alloresponses and significantly prolonged skin graft survival (MST > 40 days). Next, mF4-31 mAbs were tested for their ability to impact indirect alloimmunity and rejection of minor antigen-mismatched allografts. B6 mice were transplanted with B6-GFP skin or cardiac allografts and treated with mF4-31C, as described above. We observed a marked reduction of the indirect alloresponse by T cells as well as well as a prolongation of graft survival (> 25 days for both skin and heart transplants). Therefore, blockade of lymphangiogenesis represents a promising approach for the inhibition of indirect alloreactivity and may be used in combination with leukocyte costimulation blockade or conventional immunosuppression to prolong allograft survival.

Evaluation of the Therapeutic Potential of Bone Marrow-Derived Myeloid Suppressor Cell (MDSC) Adoptive Transfer in Mouse Models of Autoimmunity and Allograft Rejection

Therapeutic use of immunoregulatory cells represents a promising approach for the treatment of uncontrolled immunity. During the last decade, myeloid-derived suppressor cells (MDSC) have emerged as novel key regulatory players in the context of tumor growth, inflammation, transplantation or autoimmunity. Recently, MDSC have been successfully generated in vitro from naive mouse bone marrow cells or healthy human PBMCs using minimal cytokine combinations. In this study, we aimed to evaluate the potential of adoptive transfer of such cells to control auto- and allo-immunity in the mouse. Culture of bone marrow cells with GM-CSF and IL-6 consistently yielded a majority of CD11b+Gr1hi/lo cells exhibiting strong inhibition of CD8+ T cell proliferation in vitro. However, adoptive transfer of these cells failed to alter antigen-specific CD8+ T cell proliferation and cytotoxicity in vivo. Furthermore, MDSC could not prevent the development of autoimmunity in a stringent model of type 1 diabetes. Rather, loading the cells prior to injection with a pancreatic neo-antigen peptide accelerated the development of the disease. Contrastingly, in a model of skin transplantation, repeated injection of MDSC or single injection of LPS-activated MDSC resulted in a significant prolongation of allograft survival. The beneficial effect of MDSC infusions on skin graft survival was paradoxically not explained by a decrease of donor-specific T cell response but associated with a systemic over-activation of T cells and antigen presenting cells, prominently in the spleen. Taken together, our results indicate that in vitro generated MDSC bear therapeutic potential but will require additional in vitro factors or adjunct immunosuppressive treatments to achieve safe and more robust immunomodulation upon adoptive transfer.

Pregnancy primes anti-fetal T cell memory capable of allograft destruction (TRAN3P.874)

Abstract Pregnancy-induced anti-fetal antibody can destroy allografts and excludes many women from transplantation, but anti-fetal T cell responses are poorly understood and are not currently evaluated in potential organ recipients. To test whether pregnancy (PG) primes graft-reactive T cell memory, we compared Ova skin graft survival (GS) between naive B6 mice (N), mice mated to Ova transgenic (tg) males (Ova PG-sensitized; OP), or mice sensitized by a previous Ova skin graft (OS). Skin grafts were placed 30 days after either Ova pup delivery (OP group) or after rejection of an Ova skin graft (OS group). OP females rapidly rejected Ova skin grafts with second set kinetics identical to OS females [GS (days): 11.3±1.5(OP) vs. 10.3±0.6(OS) vs. 15±0.7(N); p&amp;lt;.01]. To test the effects on antigen-specific T cells, mice were injected with Ova-specific TCR tg T cells. Flow cytometric analysis 30 days after pup delivery revealed memory T cell differentiation in response to fetal antigen [%anti-Ova CD8+CD44+CD62L-: 85%(Ova-mated) vs. 38%(Balb/c-mated)]. OP mice also produced enhanced effector T cells upon secondary challenge with an Ova skin graft [%anti-Ova CD8+IFNγ+: 60%(OP) vs. 43%(Balb-mated) vs. 35%(N)]. These results indicate that PG can prime T cell memory that gives rise to secondary effector T cells that mediate rapid graft destruction. Stimulation of PG-induced anti-fetal T cell memory may contribute to the inferior GS observed in women who receive a transplant from a child or spouse.

Mesenchymal Stem Cells Secrete Immunologically Active Exosomes

Mesenchymal stem cells (MSCs) have been shown to secrete exosomes that are cardioprotective. Here, we demonstrated that MSC exosome, a secreted membrane vesicle, is immunologically active. MSC exosomes induced polymyxin-resistant, MYD88-dependent secreted embryonic alkaline phosphatase (SEAP) expression in a THP1-Xblue, a THP-1 reporter cell line with an NFκB-SEAP reporter gene. In contrast to lipopolysaccharide, they induced high levels of anti-inflammatory IL10 and TGFβ1 transcript at 3 and 72 h, and much attenuated levels of pro-inflammatory IL1B, IL6, TNFA and IL12P40 transcript at 3-h. The 3-h but not 72-h induction of cytokine transcript was abrogated by MyD88 deficiency. Primary human and mouse monocytes exhibited a similar exosome-induced cytokine transcript profile. Exosome-treated THP-1 but not MyD88-deficient THP-1 cells polarized activated CD4(+) T cells to CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) at a ratio of one exosome-treated THP-1 cell to 1,000 CD4(+) T cells. Infusion of MSC exosomes enhanced the survival of allogenic skin graft in mice and increased Tregs.

Bcl-2 Inhibition to Overcome Memory Cell Barriers in Transplantation

Memory T cells (Tm) represent a major barrier for immunosuppression and tolerance induction after solid organ transplantation. Taking into consideration the critical role of the intrinsic apoptosis pathway in the generation and maintenance of Tm, we developed a new concept to deplete alloreactive Tm by targeting Bcl-2 proteins. The small-molecule Bcl-2/Bcl-XL inhibitor ABT-737 efficiently induced apoptosis in alloreactive Tm in vitro and in vivo and prolonged skin graft survival in sensitized recipients. A short course of ABT-737 induction therapy prevented Tm-mediated resistance in a donor-specific transfusion model and allowed mixed chimerism induction across Tm barriers. Since Bcl-2 inhibitors yielded encouraging safety results in cancer trials, this novel approach might represent a substantial advance to prevent allograft rejection and induce tolerance in sensitized recipients.

Agonistic CD200R1 DNA Aptamers Are Potent Immunosuppressants That Prolong Allogeneic Skin Graft Survival.

CD200R1 expressed on the surface of myeloid and lymphoid cells delivers immune inhibitory signals to modulate inflammation when engaged with its ligand CD200. Signalling through CD200/CD200R1 has been implicated in a number of immune-related diseases including allergy, infection, cancer and transplantation, as well as several autoimmune disorders including arthritis, systemic lupus erythematosus, and multiple sclerosis. We report the development and characterization of DNA aptamers, which bind to murine CD200R1 and act as potent signalling molecules in the absence of exogenous CD200. These agonistic aptamers suppress cytotoxic T-lymphocyte induction in 5-day allogeneic mixed leukocyte culture and induce rapid phosphorylation of the CD200R1 cytoplasmic tail thereby initiating immune inhibitory signalling. PEGylated conjugates of these aptamers show significant in vivo immunosuppression and enhance survival of allogeneic skin grafts as effectively as soluble CD200Fc. As DNA aptamers exhibit inherent advantages over conventional protein-based therapeutics including low immunogenicity, ease of synthesis, low cost, and long shelf life, such CD200R1 agonistic aptamers may emerge as useful and safe nonsteroidal anti-inflammatory therapeutic agents.

Oridonin inhibited transplant rejection in mice

Objective To investigate the role of oridonin in preventing skin graft rejection.Methods BALB/c mice were transplanted with skin grafts from C57BL/6 mice.Grafted mice were treated daily with oridonin,CsA and PBS,respectively.The survival of grafts was inspected daily and evaluated by histological analysis.On day 7 after transplantation,the percentage of CD4+ CD25+ Foxp3+ cells (Treg) in the spleen was determined by flow cytometry.The effect of oridonin on MLR and apoptosis was examined in vitro.Naive BALB/c mice were intraperitonealy injected with oridonin (15 mg/kg/day).At different time points,the number of T cells and macrophages in peripheral blood mononuclear cells (PBMCs) as well as the spleen was examined.Results The survival of skin grafts in the oridonin group (15.8 ± 1.5 days) was significantly longer than that in the control group (12.3 ± 1.2 days) and the CsA group (13.3 ± 1.1 days).Oridonin reduced inflammatory cell infiltration in grafts.The expression of Tregs was higher in the oridonin group (17.6 ± 3.6％) than in the control group (14.8 ± 2.3％).In vitro oridonin inhibited MLR and induced apoptosis in a dose-dependent manner.The number of T cells in PBMCs was rapidly decreased following oridonin treatment.With the depletion of T cells in PBMCs,high frequency of granulocytes was observed.On day 8,the number of T cells in the spleen was decreased,which was accompanied by increased phagocyte number.Conclusion Oridonin could suppress allograft rejection and prolong survival of skin grafts.The mechanism may be attributed to upregulation of Tregs and clearance of T cells. Key words: Oridonin; graft rejction; apoptosis; mice

Increasing engraftment and survival of full-thickness skin grafts with use of stromal-vascular fraction derived from adipose tissue

Increasing engraftment and survival of full-thickness skin grafts with use of stromal-vascular fraction derived from adipose tissue

Adipose Tissue-Derived Mesenchymal Stem Cells Increase Skin Allograft Survival and Inhibit Th-17 Immune Response

Adipose tissue-derived mesenchymal stem cells (ADSC) exhibit immunosuppressive capabilities both in vitro and in vivo. Their use for therapy in the transplant field is attractive as they could render the use of immunosuppressive drugs unnecessary. The aim of this study was to investigate the effect of ADSC therapy on prolonging skin allograft survival. Animals that were treated with a single injection of donor allogeneic ADSC one day after transplantation showed an increase in donor skin graft survival by approximately one week. This improvement was associated with preserved histological morphology, an expansion of CD4+ regulatory T cells (Treg) in draining lymph nodes, as well as heightened IL-10 expression and down-regulated IL-17 expression. In vitro, ADSC inhibit naïve CD4+ T cell proliferation and constrain Th-1 and Th-17 polarization. In summary, infusion of ADSC one day post-transplantation dramatically increases skin allograft survival by inhibiting the Th-17 pathogenic immune response and enhancing the protective Treg immune response. Finally, these data suggest that ADSC therapy will open new opportunities for promoting drug-free allograft survival in clinical transplantation.

Comparison of scalp and abdomen as split-thickness skin graft donor sites for aural stenosis repair

To evaluate and compare the scalp and the abdomen as split-thickness skin graft donor sites for aural stenosis repair. A total of 34 patients with aural stenosis were included in the study. All the patients underwent meatoplasty using split-thickness skin grafts. Among them, the skin graft donor site was the scalp in 11 patients and the abdomen in the other 23 patients. The surgical team followed the patients in the outpatient department for at least 6 months after surgery. Evaluations concerned healing of the donor site, hair regeneration of the donor site, survival of split-thickness skin grafts, reoccurrence of aural stenosis and hair growth in the ear canal. The incidences of reoccurrence of aural stenosis in the two groups were compared. Subjective scar evaluation of the donor sites was performed using the Patient Scar Assessment Scale (PASA). The scale items were pain, itching, color, stiffness, thickness and irregularity. All the scalp and abdominal donor sites healed well with no sign of infection. Hair regrowth and reepithelialization was observed at all the scalp donor sites. Pink discoloration was observed at the scalp donor sites in six patients 2-3 months after surgery and disappeared 6-9 months after surgery. Scars were observed at the scalp donor sites in two patients 6 months after surgery. No alopecia was observed at the scalp donor sites. The scars and pink discoloration were hidden in the hair. Scars and/or discoloration were observed at all the abdominal donor sites 12 months after surgery. All the scalp and abdominal skin grafts survived with no sign of infection. Hair growth was observed in the ear canals in two patients in the scalp group. The incidences of reoccurrence of aural stenosis were 0 % (0/23) in the abdominal group and 9.1 % (1/11) in the scalp group, respectively (Chi square test, p > 0.05). The PASA values about color, stiffness, thickness and irregularity were higher in the abdominal group than in the scalp group (Mann-Whitney U test, p < 0.001). The PASA values about pain and itching were the same (Mann-Whitney U test, p > 0.05). The scalp meets most requirements of an ideal donor site of skin grafts for aural stenosis. The advantages of scalp as a donor site include easy accessibility in the operative field, simple postoperative care, low risk of infection, rapid wound healing, minimal interference with rehabilitation, and minimal scar formation.

Autologous Transplantation of Adipose-Derived Stem Cells Enhances Skin Graft Survival and Wound Healing in Diabetic Rats

Diabetes can lead to impaired wound healing and skin grafts used surgically for diabetic wounds are often complicated with necrosis, although different therapies have been proposed. Adipose-derived stem cells (ASCs) participate in tissue repair processes and may have a role during impaired wound healing. In this study, autologous transplantation of ASCs was used to determine if it increases angiogenesis and skin graft survival and enhances wound healing in diabetic rats. Adipose-derived stem cells were successfully isolated and cultured. A full-thickness skin graft model was used to determine the effects of locally administered ASCs in 10 rats rendered diabetic (group 1), whereas 10 others served as controls (group 2). Histological examination of skin grafts followed after 1 week. Additionally, immunohistochemical staining intensity of vascular endothelial growth factor (VEGF) and transforming growth factor β3 (TGF-β3) was assessed in all grafts. The gross and histological results showed significantly increased survival, angiogenesis, and epithelialization. Mean area of graft necrosis was significantly less in group 1 than in group 2 (7.49% vs 39.67%, P < 0.001). Statistically significant increase of capillary density, collagen intensity, VEGF, and TGF-β3 expression was noted in group 1 compared with group 2. These findings suggest that autologous ASC transplantation can enhance skin graft survival in diabetic rats through differentiation, vasculogenesis, and secretion of growth factors such as VEGF and TGF-β3. This might represent a novel therapeutic approach in skin graft surgery for diabetic wounds.

Donor-specific tolerance induction in organ transplantation via mixed splenocytes chimerism.

We have shown previously that donor-derived splenocytes can replace recipients' bone marrow and induce donor-specific tolerance (DST). We have also shown the usefulness of the chimeric state for the induction of DST. Further analysis of mixed splenocytes chimera, especially the role of each T cells in mixed splenocytes chimera, is indispensable issue for its clinical use. A chimeric state has been shown to achieve long-term survival in major histocompatibility complex (MHC)-mismatched grafts. The donor-derived splenocytes can replace recipients' bone marrow and induce DST. The long-term survival of allogeneic skin grafts was achieved without immunosuppressants. In this study we show the role of each T cell type in a splenocyte mixed chimera. This review provides a short summary of our original work, adding some supplemental interpretations. Mixed chimerism is thus considered an attractive approach for the induction of DST without the use of immunosuppressants. In this paper, we summarize some of the findings on mixed splenocyte chimeras and review mixed chimerism in recent organ transplantation.

Cyclosporine Combined With Nonlytic Interleukin 2/Fc Fusion Protein Improves Immune Response to Hepatitis B Vaccination in a Mouse Skin Transplantation Model

BackgroundImproving immune responses to vaccination in immunosuppressed patients is extremely important. Previously, we observed that cyclosporine (CsA) combined with a nonlytic interleukin (IL)-2/fragment crystallizable (Fc) fusion protein induces immune tolerance to mouse skin transplantations. In the present study, we asked whether this combination improved hepatitis B (HBV) vaccine efficacy in immunosuppressed mice while also prolonging skin graft survival. MethodsAfter C57BL/6 mice received DBA/2 skin grafts, they were administered a 14-day course of CsA (30 mg/kg intraperitoneal) combined with IL-2/Fc (1μg, intraperitoneal). HBV vaccine (2 μg) was injected intramuscularly on the day of skin transplantation. On day 14, the serum levels of hepatitis B surface antibody (HBsAb), IL-4, IL-10, interferon (IFN-γ), and IL-2 were measured by enzyme-linked immunosorbent assay. We assessed the percentages of CD4+CXCR5+ follicular T helper cells, CD4+FoxP3+ regulatory T cells (Treg) and expressions of IL-17, IL-21, FoxP3, Bcl-6 in the spleen. Animals were divided into four groups: control, vaccine-treated, CsA + vaccine-treated, CsA + IL-2/Fc + vaccine-treated hosts. ResultsCombination therapy significantly increased HBsAb levels and also prolonged skin graft survival. Serum levels of Th1 cytokines IL-2 and IFN-γ were significantly higher in the combination group, while Th2 cytokines, IL-4 and IL-10 were lower. Combined treatment increased the percentage of Treg and the expression of Foxp3 and IL-21, meanwhile inhibiting the expression of Bcl-6. But the percentage of Tfh did not significantly change among the groups. ConclusionsThese observations suggested that a combination of CsA and IL-2/Fc fusion protein enhanced immune responses after HBV vaccination and prolonged skin graft survival.

The Effect of Atorvastatin (Lipitor) on the Duration of Survival of Allogeneic Skin Graft and the Growth of B16F10 Melanoma Cells in Mice

The Effect of Atorvastatin (Lipitor) on the Duration of Survival of Allogeneic Skin Graft and the Growth of B16F10 Melanoma Cells in Mice

SAT0187 Immunomodulatory effects of human umbilical cord wharton jelly-derived mesenchymal stem cells (HUCMS) on circulating T-cell subsets in patients with sjögren’s syndrome

BackgroundhUCMS are adult stem cells easy to retrieve in bulk. Their immunomodulatory and pro-differentiation properties has been demonstrated. Indeed they may suppress lymphocyte activation, thereby prolonging skin graft survival time....

Fundamental Immunology of Skin Transplantation and Key Strategies for Tolerance Induction

Transplantation of allogeneic or xenogeneic skin grafts can evoke strong immune responses that lead to acute rejection of the graft tissues. In this process, donor-derived dendritic cells play crucial roles in the triggering of such immune responses. Both the innate and acquired host immune systems participate in graft rejection. At present, the rejection of skin grafts cannot be well-controlled by ordinary systemic immunosuppression therapy. Although several strategies for the long-term survival of allogeneic or xenogeneic skin grafts have been demonstrated in animal models, the induction of long-term tolerance to skin grafts is still a great challenge in clinical settings. In this article, we review the progress in the understanding of immune responses to skin grafts and discuss the possible methods that can decrease the immunogenicity of graft tissues and improve the survival of skin grafts, especially those included in preoperative pre-treatments.

Tolerogenic Donor-Derived Dendritic Cells Risk Sensitization In Vivo owing to Processing and Presentation by Recipient APCs

Modification of allogeneic dendritic cells (DCs) through drug treatment results in DCs with in vitro hallmarks of tolerogenicity. Despite these observations, using murine MHC-mismatched skin and heart transplant models, donor-derived drug-modified DCs not only failed to induce tolerance but also accelerated graft rejection. The latter was inhibited by injecting the recipient with anti-CD8 Ab, which removed both CD8(+) T cells and CD8(+) DCs. The discrepancy between in vitro and in vivo data could be explained, partly, by the presentation of drug-modified donor DC MHC alloantigens by recipient APCs and activation of recipient T cells with indirect allospecificity, leading to the induction of alloantibodies. Furthermore, allogeneic MHC molecules expressed by drug-treated DCs were rapidly processed and presented in peptide form by recipient APCs in vivo within hours of DC injection. Using TCR-transgenic T cells, Ag presentation of injected OVA-pulsed DCs was detectable for ≤ 3 d, whereas indirect presentation of MHC alloantigen by recipient APCs led to activation of T cells within 14 h and was partially inhibited by reducing the numbers of CD8(+) DCs in vivo. In support of this observation when mice lacking CD8(+) DCs were pretreated with drug-modified DCs prior to transplantation, skin graft rejection kinetics were similar to those in non-DC-treated controls. Of interest, when the same mice were treated with anti-CD40L blockade plus drug-modified DCs, skin graft survival was prolonged, suggesting endogenous DCs were responsible for T cell priming. Altogether, these findings highlight the risks and limitations of negative vaccination using alloantigen-bearing "tolerogenic" DCs.

TL1A-Ig induces transplantation tolerance (P1003)

Abstract Tumor necrosis factor (TNF) superfamily member 15 (TL1A) is the natural ligand for TNFRSF25. We previously reported that TNFRSF25 stimulation with an agonist antibody 4C12 selectively expands pre-existing Tregs in vivo. To compare TL1A to 4C12, we generated a soluble mouse hexameric TL1A-Ig fusion protein. TL1A-Ig mediates proliferation of Foxp3+ Treg in vitro. TNFRSF25 stimulation by TL1A-Ig in vivo induces expansion of Tregs to 30-35% of all CD4+ T cells in the peripheral blood within 5 days of treatment. With daily injections of TL1A-Ig elevated levels of Tregs can be maintained for at least 20 days. TL1A-Ig expanded Tregs express high levels of the activation/memory markers KLRG1 and CD103 and are highly suppressive ex vivo. TL1A-Ig mediated Treg expansion in vivo is protective against allergic lung inflammation by reversing the ratio of Tconvs:Tregs in the lung and blocking eosinophil exudation into the bronchoaveolar fluid. We tested the potential of TNFRSF25 agonists in transplant tolerance in several models. (1) TL1A-Ig injections 12 days after injection of allogeneic splenocytes caused diminished alloantigen-specific T cell responses in mixed lymphocyte reactions as compared to mice treated with allogeneic splenocytes only. (2) TNFRSF25 mediated Treg expansion in vivo significantly prolonged allogeneic skin graft survival. Thus, TL1A-Ig fusion proteins are potent and tightly controllable agents that may provide therapeutic benefit in asthma and transplant tolerance.

Immune Tolerance of Skin Allograft Transplantation Induced by Immature Dendritic Cells of a Third Party Carrying Donor Antigens in Mice

BackgroundDendritic cells (DCs) are the most powerful antigen-presenting cells in the body. Immature DCs (imDCs) can induce transplantation tolerance. In this study, using a mouse model of skin transplantation. We explored the antigen uptake by imDCs, changes in phenotype and function after antigen loading, as well as survival of skin grafts. MethodsMononuclear cells from C57BL/6 mice mixed with a tritiated leucine ([3H]Leu) antigen supernate were incubated with Kunming mice imDC and mature DCs. We recorded the expressions of surface molecules that were detected using flow cytometry, mixed lymphocyte reactions, mean survival times, and postoperative morphological changes in skin grafts. ResultsAfter the addition of allogeneic antigen supernate, the counts per minute of imDCs were significantly higher than those of mature DCs. The expression rates of IA/IE and CD80 significantly increased on the cell surface of imDCs. The counts per minute of imDCs in mixed lymphocyte reactions in the presence of allogeneic antigens was significantly higher than those of controls. Comparing mean survival times with controls, skin grafts were significantly longer in the imDCs groups from donors or from a third party carrying donor antigens. ConclusionsImDCs display a strong antigen uptake, gradually maturing in terms of phenotype and function after loading. Complementary application of cytotoxic T-lymphocyte–associated antigen 4 immunoglobulin blocks the immune response of imDCs. Both imDCs from the third party carrying donor antigens and those from the donor strain can establish antigen-specific immune tolerance to allogeneic skin grafts.