Long-term outcome and recurrence of hepatitis B virus following liver transplantation from hepatitis B surface antigen-positive donors in a Chinese population.

Due to the severe shortage of the donor pool in China, a large number of patients are waiting for a suitable liver, or even worse lose the opportunity of transplantation. Reasonable use of hepatitis B surface antigen-positive (HBsAg-positive) donors is one possible strategy to increase the donor pool but the long-term outcome in a Chinese population is unknown. To evaluate the safety of using of HBsAg-positive donor for liver transplantation, we set up a multicentric retrospective study from 1 January 2007 to 31 December 2012. A total of 8632 patients underwent liver transplantation during the period and 282 (2.97%) received a liver from a HBsAg-positive donor. A total of 259 cases in both the case and control groups were matched. The incidence of postoperative liver dysfunction, early-stage and long-term complications and the 1-, 3- and 5-year patient survival (78.92% vs 85.65%, 60.41% vs 69.14%, 58.08% vs 69.14%, respectively) showed no difference between the two groups (P value > 0.05). However, the 1-, 3- and 5-year HBV recurrence for patients received the HBsAg-positive donor was higher compared with controls (5.85% vs 1.97%, 11.63% vs 4.46%, 17.94% vs 4.46%, respectively, P value = 0.016). Our results showed the use of HBsAg-positive donors is feasible and postoperative antiviral therapy should be managed.

Immunoregulatory effects of sirolimus vs. tacrolimus treatment in kidney allograft recipients.

The difference in immunoregulatory effects between sirolimus and tacrolimus on kidney transplantation remains unclear. In this study, a total of 18 living-donor-related kidney transplant recipients received sirolimus (n=8) or tacrolimus (n=10) treatment. Kidney function, acute rejection, peripheral blood CD4(+)CD25(+)FOXP3(+) regulatory T cells (Tregs), CD19(+)CD5(+)CD1d(+) regulatory B cells (Bregs), and panel reactivity antibody were analyzed after one and three years. Th1/2 cell polarization was also determined at one year. The proportion of Tregs in the recipients receiving tacrolimus significantly decreased to 3.69% and 2.49% at one and three years, respectively, compared to 6.59% in controls, whereas the proportion in the recipients receiving sirolimus remained at 6.67% and 5.66%, respectively. However, no differences in kidney function, acute rejection, proportion of Bregs, panel reactivity antibody, or the frequencies of Th1/2 cells were identified. In conclusion, unlike tacrolimus, sirolimus maintains the proportion of Tregs in kidney transplant recipients.

Carbon monoxide potently prevents ischemia-induced high-mobility group box 1 translocation and release and protects against lethal renal ischemia-reperfusion injury.

High-mobility group box 1 (HMGB1) is a chromatin-binding nuclear molecule that has potent proinflammatory effects once released by damaged cells. In some disease models, carbon monoxide (CO) exhibits anti-inflammatory and protective properties. Here, we investigated whether the protective effect of CO on renal ischemia-reperfusion injury is associated with the inhibition of HMGB1 translocation and release. A renal ischemia-reperfusion injury model was established with a 100% mortality rate in untreated mice. Pretreatment with the CO-releasing molecule-2 (CORM-2) resulted in 100% survival, maximal preservation of renal function, a marked reduction in pathological damage, and blunted upregulation of TLR4, RAGE, TNF-α, IL-1ß, IL-6, and MCP1 mRNA. Interestingly, CORM-2 pretreatment almost completely inhibited ischemia-induced HMGB1 nucleocytoplasmic shuttling and release. This inhibition was associated with a decrease in nuclear histone acetyltransferase activity. Indeed, CORM-2 pretreatment inhibited the acetylation and release of HMGB1 during hypoxic culture of primary mouse renal tubular epithelia cells in vitro. Using the same renal ischemia-reperfusion injury model, neutralization of HMGB1 was protective, and administration of exogenous HMGB1 largely reversed the protective effect of CORM-2 on kidney ischemia-reperfusion injury. Thus, CORM-2-delivered CO protects against lethal renal ischemia-reperfusion injury. This protection is correlated with the prevention of HMGB1 nuclear-cytoplasmic translocation and release.

[Role of de novo HLA-DQ antibodies in renal transplantation: analysis of a single center data].

OBJECTIVE: To explore the generation pattern and clinical relevance of de novo HLA-DQ antibodies in renal transplantation. METHODS: A total of 175 primary renal transplant recipients without pre-transplant HLA antibodies were recruited from January 2012 to December 2013. The average follow-up period was 10 (6-18) years. They were divided into control group (n = 94) with normal renal graft function (serum creatinine <120 µmol/L); dysfunction group (n = 54) with continued serum creatinine >150 µmol/L over 6 months; and graft loss group (n = 27) with resumed hemodialysis. The sera were collected and screened for de novo HLA antibodies by flow PRA or Luminex mixed beads. And HLA-A, -B, -DR and -DQ specific antibodies were identified by HLA single antigen beads. RESULTS: Positive de novo HLA antibodies were detected in 48% (26/54) of patients from dysfunction group and in 52% (14/27) from graft loss group, but only in 17% (16/94) from control group (P < 0.01). The frequency of de novo DQ antibodies among patients with any positive HLA antibody was the highest in all three groups (14/16, 24/26 and 14/14). Additionally, the average mean peak fluorescence intensity of DQ antibodies was almost the highest when compared to other antibodies. Moreover, when those with positive HLA antibodies in each group were analyzed, 10/16 in control group were detected to have DQ antibodies alone. However, 17/26 of patients in dysfunction group and 14/14 in graft loss group were detected to have DQ antibodies plus HLA-DR and/or -A, -B antibodies. It indicated that the combined presence of DQ-and non-DQ- antibodies was associated with chronic renal graft failure. CONCLUSIONS: The presence of de novo HLA-DQ antibodies is frequent after renal transplantation. And it is associated with chronic graft failure when co-displaying with other HLA antibodies. The screening and detection of HLA-DQ antibodies after kidney transplantation may aid early warning of donor antigen-specific activation of immune system and subsequent graft dysfunction. Thus it serves as an indication for early treatment.

A Case Report of Modified Pancreatic Transplantation With a Limited Splenic Arteriovenous Fistula to Elude Thrombosis.

In classic pancreatic transplantation, the splenic artery and vein are ligated at the tail of the pancreas graft. This leads to slowed blood flow in the splenic vein and may cause thrombosis and graft loss. In this study, a patient received a pancreas after kidney transplantation. A modified surgical technique was used in the pancreatic graft preparation. The donor splenic artery and vein were anastomosed end to end at the tail of the pancreas. The splenic artery near the anastomosis was partially ligated, and an effective diameter of 2 mm was reserved to limit arterial blood pressure and flow. The patient recovered very well. Contrasted computed tomography scans on days 11 and 88 after pancreas transplantation indicated sufficient backflow of the splenic vein. We believe that this procedure may avoid the risk of splenic vein thrombosis after pancreas transplantation. This modified technique has not been reported in clinical cases previously and may help reduce the risk of thrombosis after pancreas transplantation.

[Histopathological study of 268 hepatic allograft biopsies].

OBJECTIVE: To observe the histopathological features of posttransplant complications for hepatic allografts and evaluate their biopsy values. METHODS: From January 1999 to May 2011, a total of 268 percutaneous hepatic allograft biopsies were conducted in 207 recipients and the diagnostic procedures for staining, classification and staging performed according to the Banff schema and Chinese Schema on hepatic allograft rejection. RESULTS: Among them, there were ischemia/reperfusion injury (n = 26, 9.7%), acute T cell-mediated rejection (n = 83, 31.0%), acute antibody-mediated rejection (n = 12, 4.5%), chronic posttransplantation rejection (n = 31, 11.6%), immunosuppressive-induced liver injury (n = 70, 26.1%) and recurrent diseases (n = 18, 6.7%). Acute T cell-mediated rejection and drug-induced liver injury were two most common causes of allograft dysfunctions. CONCLUSION: Percutaneous hepatic allograft biopsy is valuable for the diagnosis and evaluation of various posttransplantation complications.

[Histopathologic analysis of 1500 renal allograft biopsies].

OBJECTIVE: To summarize the histopathological features of posttransplant complications for renal allografts and evaluate the biopsy values. METHODS: Between January 1997 and May 2010, a total of 1712 percutaneous renal allograft biopsies were performed in 1500 kidney transplants and diagnostic procedures for staining, classification and staging had been performed according to the Banff 1997 and 2005 Schema. RESULTS: There were 213 (14.2%) cases of acute T cell-mediated rejection post transplantation in 1500 kidney transplants. Meanwhile there were 36 (2.4%) cases of acute antibody-mediated rejection. Chronic T cell-mediated rejection and chronic antibody-mediated rejection were 251 (16.7%) cases and 45 (3.0%) cases, respectively. Acute CNI-nephrotoxicity and chronic CNI-nephrotoxicity were 106 (7.1%)cases and 251 (16.7%) cases, respectively. Relapsed or new nephropathy were 6 (0.4%) cases. Chronic CNI-nephrotoxicity is the most common cause of allograft dysfunction in the long survival recipients. CONCLUSION: Percutaneous renal allograft biopsy is valuable for the diagnosis of various posttransplantation complications.

Long-Term Clinical and Immunological Impact of Severe COVID-19 on a Living Kidney Transplant Recipient - A Case Report.

The long-term impact of COVID-19 on transplant recipients remains unknown. We describe the case of a 30-year-old male kidney transplant recipient from Wuhan, China that was treated for severe COVID-19 in February 2020. He suffered an acute lung and renal injury and required systemic treatment including adjustment of his immunosuppressant regime. He was followed up to 1-year after discharge. No chronic lung fibrosis or deterioration of his pulmonary function was observed. Despite COVID-19 mediated damage to his renal tubular cells, no transplant rejection occurred. His immunological profile demonstrated both cellular anti-SARS-CoV-2 reactivity and specific humoral immunity, indicating that it is beneficial for the transplanted patients to be immunized with SARS-CoV-2 virus vaccine. This case will help guide clinical decision making for immunocompromised individuals that become infected with SARS-CoV-2.

[Purification of Toxoplasma gondii Tachyzoites with cellulose membrane filtration and preparation of soluble antigen].

20 ml peritoneal lavage fluid of mice infected with Toxoplasma gondii RH strain was diluted to 250 ml with sterilized physiological saline, and filtered through cellulose membrane filters (pore size: 5 microm). The filtrate was centrifuged at 1512 x g for 15 min, and the sediment was pure T. gondii tachyzoites which were then sonicated. The soluble antigen was prepared by centrifugation at 11200 x g for 30 min. Sera of T. gondii infected SD rat and normal SD rats were collected for immunodetection of soluble antigen. The specificity and valence of soluble antigen were detected with indirect ELISA. The mean removal rates of mouse leukocytes and erythrocytes were 99.9% and 80.3%, respectively, and recovery rate of tachyzoites was 71%. The soluble antigen was extracted from purified T. gondii (1.38 mg per mouse). Indirect ELISA showed that the lowest effective antigen concentration was 5 microg/ml.

Correction to: A novel organ preservation solution with efficient clearance of red blood cells improves kidney transplantation in a canine model.

[This corrects the article DOI: 10.1186/s13578-018-0226-2.].

A 14-Year Follow-Up of a Combined Liver-Pancreas-Kidney Transplantation: Case Report and Literature Review.

Objective: To investigate the long-term effect of triple organ transplantation (liver, kidney, and pancreas) in a patient with end-stage liver disease, post chronic hepatitis B, cirrhosis, chronic renal failure, and insulin-dependent diabetes mellitus caused by chronic pancreatitis and to explore the optimal surgical procedure. Case: A 43-year-old man with progressive emaciation and hypourocrinia for 2 months. Results indicated exocrine pancreatic insufficiency and insulin-dependent diabetes related to chronic pancreatitis (CP) after developing end-stage hepatic and renal failure. Simultaneous piggyback orthotopic liver and heterotopic pancreas-duodenum and renal transplantation was performed in 2005. Pancreatic exocrine secretions were drained enterically to the jejunum, and the donor kidney was placed in the left iliac fossa. Patient was prescribed with prednisone, tacrolimus, mycophenolate mofetil, Rabbit Anti-human Thymocyte Immunoglobulin, and simulect for immunosuppression. Results: Satisfactory hepatic and pancreatic functional recovery was achieved within 7 days post-surgery. The kidney was not functional, and continuous renal replacement therapy was used. However, the donor kidney was removed at day 16 post-surgery due to acute rejection reaction. A new renal transplantation at the same position was performed, and satisfactory kidney function from the new graft was achieved 3 days later. In 14 years of follow-up, patient has not had any rejection reactions or other complications such as pancreatitis, thrombosis, and localized infections. The patient is insulin independent with normal liver and renal functions. FK506+Pred was used for immunosuppression, and the tac tough level maintained 3.0-4.5 ng/ml. Lamivudine was prescribed for long-term use to inhibit HBV virus duplication. Conclusion: Simultaneous piggyback orthotopic liver and heterotopic pancreas-duodenum and renal transplantation is a good therapeutic option for patients with exocrine pancreatic insufficiency and insulin-dependent diabetes combined with hepatic and renal failure.

The current state of pancreas-kidney transplantation in China: the indications, surgical techniques and outcome.

It is currently estimated that 50 million Chinese have diabetic mellitus (DM) with more than 90% of these being afflicted with type 2 DM. Concomitantly, the socio-economic improvements in China are supporting the adoption of pancreas-kidney transplantations as a treatment option for these patients. Recipient candidate pool has yet to be expanded and the final effect to be improved in clinical practice. To date, more than 250 pancreas-kidney transplants have been performed on patients with type 1 and type 2 DM. To improve the outcome, a new surgical technique that involves anastomosis of the graft duodenum to recipient jejunum side-to-side but not Roux-en-Y, has been devised for enteric drainage. Furthermore, the systemic venous drainage (SVD) has been used as the method of choice for endocrine secretions. Graft and recipient long-term survival in China was similar to that in America and Europe. Three-year survival rate of pancreas and kidney grafts was 92.2% and 90.2%, respectively, in our center. No difference in survival and graft function between type 1 and type 2 DM recipients was noted. It is concluded that pancreas-kidney transplantation is an effective way for the treatment of type 1 DM and some type 2 DM complicated with uremia.

A novel organ preservation solution with efficient clearance of red blood cells improves kidney transplantation in a canine model.

Organ preservation solutions are designed to minimize organ damage during transplantation. A novel preservation solution, WMO-II, was developed to have a low viscosity and to improve microvasculature perfusion for kidneys. In an autologous canine transplantation model, kidney function and recovery were evaluated after organs were flushed and cold-stored with WMO-II or HTK solution, a perfusate currently approved for clinical use. The average number of red blood cells remaining in a single glomerulus after flushing with WMO-II was significantly reduced when compared with HTK solution. Additionally, WMO-II reduced the number of apoptotic bodies in stored kidneys compared to HTK treated tissue after 48 h of cold storage by reducing expression of Caspase-9, BiP, Chop, and Caspase-12. WMO-II solution reduced serum creatinine levels and serum potassium in kidneys stored for 48 h when compared to HTK perfusion. WMO-II preserves kidney function as evidenced by the reduction in serum creatinine and potassium during graft transplantation.

Impact of early biliary complications in liver transplantation in the presence or absence of a T-tube: a Chinese transplant centre experience.

BACKGROUND: Biliary complications continue to be an important determinant of the recipient's survival rate after orthotopic liver transplantation (OLT). The objective of this study was to evaluate the incidence of early biliary complications in OLT in the presence or absence of a T-tube. METHODS: This retrospective study, based on inpatient data, focused on the relationship between T-tube placement and early biliary complications of 84 patients after OLT, from November 2002 to June 2005. Patients were divided into two groups based on whether or not a T-tube was used following bile duct reconstruction: T-tube group (group I, n = 33); non-T-tube group (group II, n = 51). RESULTS: 45.2% of OLT recipients had a malignant neoplasm. There were no significant differences in the demographic characteristics or operation data between the two groups. Overall, early biliary tract complications developed in 19.0% (16/84) of patients. The rate of early biliary complications was 30.3% (10/33) and 11.8% (6/51) in groups I II, respectively (p = 0.035). Biliary complications which were directly caused by T-tube placement occurred in 12.1% (4/33) of patients in group I. Overall, the percentage of malignant neoplasms, chronic viral cirrhosis, fulminant liver failure and other primary disease recipients with early biliary complications were 6.2%, 37.5%, 43.8% and 12.5%, respectively. CONCLUSION: This study suggests that the use of a T-tube in Chinese patients undergoing OLT causes a higher incidence of early biliary complications. Most of the early biliary complications occurred in chronic viral cirrhosis and fulminant liver failure recipients.

Progress in pancreas transplantation and combined pancreas-kidney transplantation.

BACKGROUND: Pancreas transplantation (PT) has proved effective but it is associated with a high risk of surgical complications and technical failure. Duct management and venous drainage are identified as major issues. Improvements in immunosuppression and prophylaxis greatly have contributed to surgical progress. DATA SOURCES: A literature search of the PubMed database (1996-2005) was conducted and research articles on PT reviewed. RESULTS: More than 23 000 PTs have been performed throughout the world. The majority (83%) were performed in combination with kidney transplantation [simultaneous pancreas-kidney transplantation (SPK)]. Pancreas graft survival rates at one year were 85% for 2001-2003 SPK cases, 79% for pancreas after kidney transplantation (PAK) cases, and 76% for pancreas transplantation alone (PTA) cases. For the 1999-2003 cases, enteric drainage was done in 79% of the SPK cases and bladder drainage in 21%. Patient survival rates, pancreas and kidney graft survival rates, and pancreas graft immunological failure rates did not differ significantly in enteric versus bladder drainage cases. All the available data fail to demonstrate a definitive advantage of portal drainage over systemic drainage. From 1993 to 2002, the use of rabbit antithymocyte globulin increased from 0 to 37%; the use of daclizumab increased from 0 to 16%; and the use of basiliximab increased from 0 to 25%. In 1993, 98% of SPK recipients received cyclosporine; but this was decreased to 9% in 2002. Tacrolimus (FK506) usage has increased from 0 (1993) to 87% (2002) of SPK recipients. Sirolimus (SIR) usage has increased from 0 (1993) to 18% (2002) of SPK recipients. CONCLUSIONS: PT remains an effective therapy for treatment of type I diabetes mellitus. Enteric drainage is currently predominant in SPK, but bladder drainage is still largely used. Portal drainage is as safe as systemic drainage, but there is still no convincing evidence about whether it is immunologically or metabolically convenient. The combined of FK506 and mycophenolate mophetil (MMF) is the preferred maintenance immunosuppression in PT. Sirolimus may be a good alternative as a second agent in recipients of PT under FK506 therapy.

[Technology and application of simultaneous pancreas-kidney transplantation with modified enteric drainage].

OBJECTIVE: To report the modified technique and the short-term results of simultaneous pancreas-kidney transplantation (SPK) with the enteric drainage (ED) of exocrine secretions. METHODS: From June 2000 to August 2006, thirty-eight patients with diabetes complicated with uremia underwent SPK. The pancreas graft was placed intraperitoneally with exocrine secretions drained into the proximal jejunum without Roux-en-Y procedure. The mean cold ischemic times of pancreas and kidney were (10 +/- 2.0) h and (7 +/- 2.0) h, respectively. Quadruple immunosuppressive therapy with antilymphocyte globulin or anti-CD25 monoclonal antibody, tacrolimus, mycophenolate mofetil and steroids was adopted except one patient. RESULTS: The 6-month survival rates of patients and grafts were both 97.4% after transplantation. All patients achieved insulin-free euglycemia at (7 +/- 6.9) d postoperative except one. For preoperative patients, mean fasting insulin and C-peptide values were (9 +/- 8.1) mU/L and (6 +/- 4.5) mU/L. After operation, fasting insulin and C-peptide values of patients were (12 +/- 5.8) mU/L and (6 +/- 4.7) mU/L, respectively, which peaked to an insulin level of (57 +/- 43.0) mU/L and a C-peptide level of (11 +/- 6.8) mU/L with stimulation. There were eight cases of delayed renal graft function. All other patients achieved immediate renal graft function. No graft losses occurred due to leakage or intra-abdominal infection. The most common surgical complications were wound infection (n = 12), enteric anastomostic hemorrhage (n = 5) and perirenal hemorrhage (n = 2). Three patients (7.9%) had been reoperated for the reasons of intra-abdominal hemorrhage and perirenal hemorrhage. CONCLUSIONS: SPK is an effective treatment option for selected patients with diabetes mellitus and approaching end-stage renal disease. Enteric exocrine drainage by direct side-to-side anastomosis (without Roux-en-Y) seems to be a simple and reliable technique.

Dynamic changes of phenotypes and secretory functions during the differentiation of pre-DCs to mature DCs.

The dynamic expression of cytokines and phenotypes during the differentiation process of dendritic cell precursors (pre-DCs) to mature dendritic cells (DCs) was investigated, and the effects of inflammatory stimulation with lipopolysaccharide (LPS) on DCs differentiation were understood. The differentiation of bone marrow cells isolated from Balb/c mice was induced to DCs in an 8-day cell culture system with RPMI-1640 complete culture medium containing 10% FBS, 20 ng/mL recombinant mouse granulocyte-macrophage colony-stimulating factor (rmGM-CSF) and 10 ng/mL recombinant mouse interleukin-4 (rmIL-4). On the day 3, 6 and 7 after culture, DCs were divided into non-LPS group and LPS group, given 500 ng/mL LPS for 24 h stimulation and no stimulation respectively. The expression levels of CD11c+, MHC-II+, CD40+, CD80+ and CD86+ were detected by flow cytometry, and those of IL-2, IL-4, IL-10, IL-12 p70 and IFN-γ in the supernatant by ELISA. On the day 3 and 6 after culture, the expression of IL-2, IL-4, IL-10 and IFN-γ in DCs showed no significant differences between non-LPS group and LPS group, whereas the differences were significant at day 7. The expression levels of cytokines (for IL-2, IL-4, IL-10, IFN-γ and IL-12 p70: 152.86±6.91, 778.33±8.35, 44.55±2.54, 58.26±1.09 and 2423.00±57.21 pg/mL respectively) in LPS group were higher than those in non-LPS group, especially IL-12 p70 increased obviously at day 7. It was concluded that during the differentiation process of pre-DCs to mature DCs, LPS stimulates DCs producing large amounts of IL-12 p70 and Th1-type cytokines as compared with Th2-type cytokines, and day 7 may be a key time-point for DCs polarization.

Graft-versus-host-disease after kidney transplantation: A case report and literature review.

INTRODUCTION: Acute graft-versus-host-disease (GVHD) in kidney recipients is extremely rare. Knowledge about its clinical manifestations, diagnosis, treatment, and prognosis is limited and needs to be increased. CLINICAL FINDINGS: One male kidney transplant recipient developed diarrhea and suffered kidney function damage. Primarily diagnosed with acute rejection, he was given methylprednisolone (MP) bolus treatment. Meanwhile, intravenous immunoglobulin (IVIG) and decreased immunosuppressive agents were applied for the corresponding infection. During the treatment, skin rashes occurred over his whole body. Biopsies were then taken. The pathology of the kidney graft showed no rejection, while the skin pathology revealed typical GVHD. Furthermore, fluorescence in situ hybridization proved the presence of donor-derived cells in the skin lesions, and infiltrating cytotoxic T cells and NK cells were identified in the rash. OUTCOME: Based on the clinical presentations, pathological findings, and chimerism detection, GVHD after kidney transplantation was confirmed as the final diagnosis. The recipient responded well to treatment. His kidney function recovered, and the skin lesions were completely resolved. He has been followed for 1 year without any further episodes. CONCLUSION: GVHD after kidney transplantation has its own characteristics. In the presence of a highly immunocompromised state, diarrhea and rashes, a diagnosis of GVHD needs to be considered. Kidney function impairment may be involved. Pathological changes and detection of chimerism and immunocyte infiltration are required for diagnosis. MP bolus, IVIG, and decreased immunosuppression could be beneficial to the clinical outcome. Kidney recipients have a prognosis superior to recipients of organs bearing large numbers of lymphocytes.

Discrimination of the heterogeneity of bone marrow­derived dendritic cells.

The present study aimed to discriminate different subsets of cultured dendritic cells (DCs) to evaluate their immunological characteristics. DCs offer an important foundation for immunological studies, and mouse bone marrow (BM) cells cultured with granulocyte­macrophage colony­stimulating factor (GM­CSF) have been used extensively to generate CD11c+/major histocompatibility complex II+ BM­derived DCs (BMDCs). Immature DCs are considered to have strong migration and phagocytic antigen­capturing abilities, whereas mature DCs are thought to activate naive T cells and express high levels of costimulatory cytokines and adhesion molecules. In most culture systems, non­adherent cells are collected as mature and qualified DCs, and the remaining adherent cells are discarded. The output from GM­CSF cultures comprises mostly adherent cells, and only a small portion of them is non­adherent. This situation has resulted in ambiguities in the attempts to understand results from the use of cultured DCs. In the present study, DCs were divided into three subsets: i) Non­adherent cells; ii) adherent cells and iii) mixed cells. The heterogeneous features of cultured DCs were identified by evaluating the maturation status, cytokine secretion and the ability to activate allogeneic T cells according to different subsets. Results from the study demonstrated that BMDC culture systems were a heterogeneous group of cells comprising non­adherent cells, adherent cells, mixed cells and firmly adherent cells. Non­adherent cells may be used in future studies that require relatively mature DCs such as anticancer immunity. Adherent cells may be used to induce tolerance DCs, whereas mixed cells may potentiate either tolerogenicity or pro­tumorigenic responses. Firmly adherent cells were considered to have macrophage­like properties. The findings may aid in immunological studies that use cultured DCs and may lead to more precise DC research.

Rat adipose-derived stem cells express low level of α-Gal and are dependent on CD59 for protection from human xenoantibody and complement-mediated lysis.

Since increasing evidence has indicated that adipose-derived stem cells (ASCs) can function across the species barrier, the use of xenogeneic ASCs may be a practical alternative to the autotransplantation and allotransplantation. Before animal ASCs can be used clinically, evidence needs to be provided to indicate whether they will survive in a human host. In the present study, we investigated whether rat ASCs (rASCs) could resist human xenoantibody and complement-mediated lysis as well as investigated the possible mechanisms involved. We found that rASCs could significantly resist human natural antibody and complement-mediated cytotoxicity when incubated with 20% or 50% normal human serum (NHS) in vitro, as compared with rat lymphocytes (rLCs). Mechanistically, rASCs expressed lower level of xenoantigen Galα1-3Galß1-4GlcNAc (α-Gal), which was correlated with decreased binding of human xenoreactive IgG and IgM and reduced deposition of complement C3c and C4c. More interestingly, rASCs had minimal deposition of human membrane attack complex (C5b-9). When the expression of CD55 and CD59 was analyzed by flow cytometry, we found that rASCs expressed very weak CD55 but expressed much higher level of CD59 than rLCs. Moreover, the knockdown of CD59 expression by siRNA largely reversed the resistance of rASCs to the human serum-mediated lysis. Taken together, these data have demonstrated for the first time that rat ASCs are capable to protect themselves from human xenoantibody and complement-mediated lysis, which is dependent on CD59 and is correlated with low expression of α-Gal. Xenogenic ASCs may have the potential to treat patients in the future.