JAK3 inhibitor-based immunosuppression in allogeneic islet transplantation in cynomolgus monkeys.

Islet transplantation is efficacious to prevent severe hypoglycemia and glycemic liability of selected patients of type 1 diabetes. However, since calcineurin inhibitor (CNI) causes ß-cell and nephrotoxicity, alternative drug(s) with similar potency and safety profile to CNI will be highly desirable. Here we tested whether JAK3 inhibitor, tofacitinib could be used instead of tacrolimus in CIT07 immunosuppression regimen in cynomolgus nonhuman primate (NHP) model. Five independent streptozotocin (STZ)-induced diabetic monkeys were transplanted with MHC-mismatched allogeneic islets and three animals were further re-transplanted upon insufficient glycemic control or early islet graft rejection. After islet transplantation, blood glucose levels were quickly stabilized and maximal islet graft survival as measured by serum C-peptide concentration was >330, 98, >134, 31, or 22 days, respectively, after transplantation (median survival day; 98 days). Cellular and humoral immune responses were efficiently suppressed by JAK3 inhibitor-based immunosuppression during the follow-up periods. Although intermittent increases of the genome copy number of cynomolgus cytomegalovirus (CMV) were detected by quantitative real-time PCR analyses, serious infections or posttransplant lymphoproliferative disease (PTLD) was not found in all animals. Taken together, we have shown that JAK3 inhibitor could be used in replacement of tacrolimus in a highly translatable NHP islet transplantation model and these results suggest that JAK3 inhibitor will be potentially incorporated in human allogeneic islet transplantation.

The exosome as a novel predictive/diagnostic biomarker of rejection in the field of transplantation.

Finding a non-invasive biomarker to monitor allograft status after transplantation could contribute to better control of the post-transplant status of transplant recipients and, if possible, could be used instead of invasive biopsy for proving rejection. On the other hand, reducing the dosage of immunosuppression or stopping lifelong use of them because of their severe side effects is an important goal in order to dispose of their severe side effects. The ability of exosomes as a biomarker of rejection and as a therapeutic strategy was investigated in the human kidney, heart, and lung transplantation or in transplantation models with interesting results. Moreover, the ability of exosome was assessed as antigen-presenting vesicles (APVs), in which exosomes can either participate in immune stimulation (semi-direct recognition) or immune suppression thereby, influence on the transplantation outcome. In this paper, authors try to provide comprehensive information about triple role of exosomes in the transplantation medicine.

Immunological Response of Pigs to Human Cells, Including Issues Such as the Production of Natural Antibodies in Newborns.

Pigs have recently become very popular for use not only in xenotransplantation field, but in regeneration studies as well, sometimes with pigs being used as the scaffold. We have already presented our findings related to the pig immune system against human cells, including the complement systems, natural antibodies (NAs), and NK cells. In this study, we investigated the pig innate immunological reaction against human cells further. Our investigations included issues such as the production of NAs in newborns, day 0 and day 1, and sow colostrum. The alternative pathway for pig complement reacted with human cells, and pig NK cells and macrophages directly injured human aortic endothelial cells. Pig serum clearly contains the natural antibodies IgG and IgM to human peripheral blood mononuclear cells (PBMCs). Pig plasma from day 1 newborns contained almost the same levels of these natural antibodies to human PBMCs as those of sow plasma. On the other hand, pig plasma from day 0 newborns did not contain IgG and IgM to human PBMCs. In addition, sow colostrum clearly contained both IgG and IgM to human PBMCs. As expected, the pig innate immunity system reacted to human cells, including natural antibodies. However, the NAs of pigs, both IgM and IgG, against human cells do not exist in pig serum at day 0, but at day 1 and in mother's milk, indicating that NAs in newborns did not come from the placenta but from sow colostrum.

Estudio pre-trasplante hepático: ¿qué buscar y cómo hacerlo? Si algo es positivo: ¿qué hacemos? / Liver transplant pre-study: what to search for and how to do it? what shall we do in case of positive findings?

The process of evaluation of candidate patients for liver transplantation should include the risk of infectious diseases in order to prevent the drop out of the waiting list due to infections or the occurrence of these in the post-transplant period. Cirrhotic patients in the pre-transplant stage are very ill and usually have severe infections. The most common is spontaneous bacterial peritonitis, but they can also present urinary infections and pneumonias. Mortality due to infectious causes has been reported up to 40% in patients on the transplant waiting list. The transplanted patients may have a poor immune response to vaccination, so the optimal immunization period is pre-transplant. In the post-transplant period, Gram-negative bacterial infections are one of the main complications. Invasive fungal infections and cytomegalovirus can also have a high impact on morbidity and mortality. Transplanted patients may also have mycobacterial infections in relation to a latent tuberculosis infection. In the following article we present the pre-transplant evaluations, vaccination schemes and antimicrobial prophylaxis that are used in liver transplantation.

El proceso de evaluación de pacientes candidatos para trasplante hepático debe incluir el riesgo de enfermedades infecciosas a fin de prevenir la salida de la lista por infecciones o la ocurrencia de éstas en el período post-trasplante. Los pacientes cirróticos en la etapa pre-trasplante están muy enfermos y suelen presentar infecciones graves. La más común es la peritonitis bacteriana espontánea, pero también pueden presentar infecciones urinarias y neumonías. La mortalidad por causa infecciosa se ha reportado hasta en 40% en pacientes en lista de espera de trasplante. Los pacientes trasplantados pueden tener una pobre respuesta inmune a la vacunación, por lo que el momento óptimo de inmunización es en el período pretrasplante. En el período post-trasplante las infecciones bacterianas por Gram negativos son una de las principales complicaciones. Las infecciones por hongos invasores y el citomegalovirus también pueden tener un alto impacto en morbilidad y mortalidad. Los pacientes trasplantados también pueden presentar infecciones por micobacterias en relación a una infección latente por tuberculosis. En el siguiente artículo se presentan las evaluaciones pre-trasplante, esquemas de vacunación y profilaxis antimicrobiana que se utilizan en trasplante hepático.

Evidence of the immunomodulatory role of dual PI3K/mTOR inhibitors in transplantation: an experimental study in mice.

The PI3K/mTOR signaling cascade is fundamental in T-cell activation and fate decisions. We showed the distinct regulation of PI3K/mTOR in regulatory and effector T-cells and proposed the potential therapeutic benefit of targeting this pathway to control the balance between effector and regulatory T-cell activities. Substantial adverse effects in long-term clinical usage of rapamycin suggest the use of alternative treatments in restraining effector T-cell function in transplant patients. We hypothesize that dual PI3K/mTOR inhibitors may represent an immunosuppressant alternative. Here we show that dual PI3K/mTOR PI-103 and PKI-587 inhibitors interfered IL-2-dependent responses in T-cells. However, in contrast to the inhibitory effects in non-Treg T-cell proliferation and effector functions, dual inhibitors increased the differentiation, preferential expansion, and suppressor activity of iTregs. Rapamycin, PI-103, and PKI-587 targeted different signaling events and induced different metabolic patterns in primary T-cells. Similar to rapamycin, in vivo administration of PI-103 and PKI-587 controlled effectively the immunological response against allogeneic skin graft. These results characterize specific regulatory mechanisms of dual PI3K/mTOR inhibitors in T-cells and support their potential as a novel therapeutic option in transplantation.

Iron metabolism in transplantation.

Recipient's iron status is an important determinant of clinical outcome in transplantation medicine. This review addresses iron metabolism in solid organ transplantation, where the role of iron as a mediator of ischemia-reperfusion injury, as an immune-modulatory element, and as a determinant of organ and graft function is discussed. Although iron chelators reduce ischemia-reperfusion injury in cell and animal models, these benefits have not yet been implemented into clinical practice. Iron deficiency and iron overload are associated with reduced immune activation, whose molecular mechanisms are reviewed in detail. Furthermore, iron overload and hyperferritinemia are associated with poor prognosis in end-stage organ failure in patients awaiting kidney, or liver transplantation. This negative prognostic impact of iron overload appears to persist after transplantation, which highlights the need for optimizing iron management before and after solid organ transplantation. In contrast, iron deficiency and anemia are also associated with poor prognosis in patients with end-stage heart failure. Intravenous iron supplementation should be managed carefully because parenterally induced iron overload could persist after successful transplantation. In conclusion, current evidence shows that iron overload and iron deficiency are important risk factors before and after solid organ transplantation. Iron status should therefore be actively managed in patients on the waiting list and after transplantation.

Ginsenoside Rg1 protects mouse liver against ischemia-reperfusion injury through anti-inflammatory and anti-apoptosis properties.

BACKGROUND: Ginsenoside Rg1, the major effective component of ginseng, possesses a variety of pharmacologic activities. The objective of this study was to investigate the effects of Rg1 on liver ischemia-reperfusion (IR) injury and explore its potential mechanisms. MATERIALS AND METHODS: Liver warm IR injury was achieved by occluding the portal vein and hepatic artery for 1 h followed by 6-h reperfusion. Eighteen mice were equally randomized into three groups: sham group, IR group, and IR plus Rg1 group (n = 6 mice per group). Mice received an intravenous dose of 20 mg/kg Rg1 or an equivalent volume of saline before ischemic insult. Liver samples and serum were collected for analyses. Serum aminotransferase, histopathology, and apoptosis were determined. Cytokines were measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The phosphorylation of nuclear factor kappa B (NF-κB) p65 was assessed by Western blotting. In addition, the effect of Rg1 in a simulated IR model in vitro was also investigated. Rg1 (100 ug/mL and 500 ug/mL) was administered 1 h before hypoxia insult, and then apoptosis was measured after 12-h reperfusion. RESULTS: Liver IR injury led to a dramatic increase in aminopherase activity, apoptosis and necrosis of hepatocytes, and production of proinflammatory cytokines. Pretreatment with Rg1 protected mice from IR-induced liver injury. Treatment with a high-dose Rg1 (500 ug/mL) significantly suppressed apoptosis compared with a lower dose or control (both P < 0.001). Phosphorylation of NF-κB p65 was increased significantly in IR group, and administration with Rg1 suppressed the level of phosphorylation. CONCLUSIONS: Pretreatment of mice with Rg1 reduced hepatocellular apoptosis and inhibited inflammatory response, which was in part through the NF-κB signaling pathway. Rg1 may provide a novel therapeutic strategy for the treatment of IR-induced liver injury.

Concise review: combining human leukocyte antigen G and mesenchymal stem cells for immunosuppressant biotherapy.

Both human leukocyte antigen G (HLA-G) and multipotential mesenchymal stem/stromal cells (MSCs) exhibit immunomodulatory functions. In allogeneic tranplantation, the risks of acute and chronic rejection are still high despite improvement in immunosuppressive treatments, and the induction of a state of tolerance to alloantigens is not achieved. Immunomodulatory properties of MSCs and HLA-G in human allogeneic tranplantation to induce tolerance appears attractive and promising. Interestingly, we and others have demonstrated that MSCs can express HLA-G. In this review, we focus on the expression of HLA-G by MSCs and discuss how to ensure and improve the immunomodulatory properties of MSCs by selectively targeting MSCs expressing HLA-G (MSCs(HLA-G+)). We also discuss the possible uses of MSCs(HLA-G+) for therapeutic purposes, notably, to overcome acute and chronic immune rejection in solid-organ allogeneic transplantation in humans. Since MSCs are phenotypically and functionally heterogeneous, it is of primary interest to have specific markers ensuring that they have strong immunosuppressive potential and HLA-G may be a valuable candidate.

The future of heart transplantation.

The field of heart transplantation has seen significant progress in the past 40 years. However, the breakthroughs in long-term outcome have seen stagnation in the past decade. Through advances in genomics and transcriptomics, there is hope that an era of personalized transplant therapy lies in the future. To see where heart transplantation truly fits into the long term, searching for and understanding the alternative approaches for heart failure therapy is both important and inevitable. The application of mechanical circulatory support has contributed to the largest advancement in treatment of end stage heart failure. It has already been approved for destination therapy of heart failure, and greater portability and ease of use of the device will be the future trend. Although it is still not prime time for stem cell therapy, clinical experiences have already suggested its potential therapeutic effects. And finally, whole organ engineering is on the horizon as new techniques have opened the way for this to proceed. In the end, progress on alternative therapies largely depends on our deeper understanding of the mechanisms of heart failure and how to prevent it.

Yin Yang of immunoregulation in organ transplantation and cancer.

The 'Yin Yang of Immunoregulation: Cancer and Organ Transplantation' meeting took place in Nantes, France on 2-3 December 2010 and was dedicated to the biology of myeloid and lymphoid immune cells in the context of cancer and transplantation. This meeting was organized by the Immunotherapy Research group of the Western France Cancer Network Cancéropole Grand-Ouest and the Immunomonitorage et Biothérapies network (IMBIO) research program, which is supported by the Région Pays de la Loire.

Transfusion-related acute lung injury (TRALI): A Canadian blood services research and development symposium.

Since the first description of transfusion-related acute lung injury (TRALI) more than 2 decades ago, we have only recently begun to learn how this disorder may occur and how to prevent it. Scientists from around the world have made great strides in identifying the possible causes of this condition. Blood banks and transfusion services have risen to the challenges of prevention. Recent introduction of restricting most plasma products to those obtained from male donors only has greatly reduced the incidence of TRALI worldwide. Scientists have recently identified the gene and protein for the human neutrophil antigen-3a associated with most mortality due to TRALI, and this presents an opportunity for a screening assay to prevent future TRALI-associated deaths. Finally, animal models of TRALI have provided insight into the possible mechanisms of this disorder and can be used to explore potential treatment modalities.

Successful long-term outcome of ABO-incompatible liver transplantation using antigen-specific immunoadsorption columns.

ABO-incompatible (ABO-I) liver transplantation has been performed essentially in patients with acute liver failure awaiting an urgent liver transplantation. Early results with ABO-I liver transplantation were disappointing with a very low graft survival rate (20-50%). The main risk is the occurrence of severe humoral and cellular rejection, vascular thrombosis, and biliary complications. In order to avoid humoral rejection and improve graft survival, total plasma exchange in combination with an intense immunosuppressive regimen has been proposed to decrease hemagglutinin titers in ABO-I liver grafts. In some centers, this regimen was associated with splenectomy, phototherapy, and portal or arterial intrahepatic infusion therapy; however, as these patients are at high risk of sepsis, a selective approach using antigen-specific immunoadsorption with immunoadsorbent columns has been successfully proposed for ABO-I living donor kidney transplantation. Few cases have been reported following liver transplantation. We report our recent experience with three adult patients (two patients with acute liver failure, and one with severe cirrhosis and hepatic encephalopathy) transplanted in an emergency situation with an ABO-I liver graft and managed with the use of GlycoSorb ABO immunoadsorbent columns and a quadruple immunosuppressive regimen with preservation of the spleen. Eight sessions were performed in the three patients. Antigen-specific immunoadsorption greatly lowered the anti-A hemagglutinin titers. None of the three patients developed acute humoral or cellular rejection. Two patients are alive at 1.5 and 3 years follow-up with a normally functioning graft. The third patient died with a functioning graft, one month after the transplantation, from septic complications.

Qualitative studies of the food safety knowledge and perceptions of transplant patients.

Organ and stem cell transplant patients are at risk for foodborne illness due to disease and medically induced immunosuppression. The food safety knowledge and informational needs of these groups have not been documented in the literature. The objectives of this study were to assess transplant patients' food safety knowledge and perceptions, to probe the likelihood of practicing safe food handling behavior, and to test an educational strategy for future food safety interventions aimed at transplant patients. Subjects were organ or stem cell transplant patients, or their family care providers. Research was conducted in inpatient or outpatient facilities at a large, Midwestern United States comprehensive cancer and transplant center. Differences in survey data between the organ and stem cell transplant groups were determined by Student's t tests. Ethnographic methods were used to analyze qualitative focus groups and interview data for themes. Organ transplant patients had less motivation to follow food safety recommendations than did stem cell transplant patients, and they were more likely to consume risky foods. Stem cell transplant patients overall had a better understanding of their susceptibility to foodborne illness and had better prepared themselves with the knowledge and behavior changes needed to protect their health. Educational materials aimed at communicating food safety information for transplant patients were evaluated by patients and judged acceptable. This study found that organ transplant and stem cell transplant patients are distinct patient populations, with differing perceptions regarding the seriousness of foodborne illness and willingness to adopt preventative food handling practices. Population differences should be accounted for in food safety educational strategies.

Tetrandrine attenuates dendritic cell-mediated alloimmune responses and prolongs graft survival in mice.

Tetrandrine, a bisbenzylisoquinoline alkaloid, has significant immunosuppressive effects; however, the effects of tetrandrine on dendritic cells (DCs) and the associated immune reactions are unclear. In this study, we investigated the effects of tetrandrine on DCs and the effects of the tetrandrine-treated DCs on alloimmune reactions in vitro and graft survival in vivo. Tetrandrine significantly downregulated the expression of CD80 and CD86 of DCs and increased their secretion of IL-10 (p = 0.0001). Mixed leukocyte reaction showed that tetrandrine inhibited dendritic-cell allo-stimulatory activity, which was reversed by the anti-IL-10 treatment. An in vivo study demonstrated that tetrandrine-treated DCs prolonged the survival time of skin grafts in mice compared to control (p = 0.005) and decreased cellular infiltration of the graft in the histopathological study. The data suggest that tetrandrine-treated DCs cause immunosuppression and protect skin grafts from rejection. The tetrandrine-induced immunosuppression seems to be partially due to increased IL-10 secretion.

Glycemic control among older adult hematopoietic cell transplant recipients.

Adults age 55 and older with hematological malignancies who require hematopoietic cell transplantation (HCT) for survival are at risk for a number of nonmalignancy-related, potentially life-threatening outcomes, often due to suboptimal immune function. Evidence is emerging regarding how abnormal glycemic levels-newly termed malglycemia-impair cells of the immune system. Further, older adult HCT recipients appear highly susceptible to malglycemic states, particularly hyperglycemia, due to treatment regimens, nutritional imbalances, states of immobility, and stress, all coupled with the natural aging process. Patients with preexisting diabetes may be at further risk for malglycemic states. The growing number of older adults receiving HCT will substantially increase the likelihood nurses will have to provide care to HCT survivors. Therefore, it is important nurses in all practice settings have an understanding of the short-and long-term effects of glycemic status on immune function.

[Monoclonal antibodies in organ transplantation]. / Anticorps monoclonaux en transplantation.

Polyclonal anti-lymphoyctes antibodies were first successfully used in the 1970 in organ transplantation, but ten years later, monoclonal antibodies (mAb) emerged as a new class of immunosuppressive agents in transplantation with the potential to target highly specifically immune cells responsible for acute rejection. Some have proved their efficacy, such as mAb recognizing CD3- and CD25-positive T cells and have been extensively studied in clinical trials. Others such as mAb against CD52 and CD20, are still under investigation; finally, the next challenge is, based on our improved understanding of the mechanisms of immune recognition and allograft rejection, to use these mAb either alone or in combination with standard immunosuppressive regimens to manipulate the allogenic response to reach antigen-specific tolerance desired in solid-organ transplantation.

Mycosis fungoides after solid-organ transplantation: report of 2 new cases.

Long-term survival after solid-organ transplantation is increasing because of recent advances, including new immunosuppressive regimens to avoid graft rejection. However, the resultant modification of the immune system is associated with an increased risk of several cancers. The most common are skin cancers, and lymphomas are second in frequency. Nevertheless, posttransplant primary cutaneous lymphomas (PCLs) are rare, and their incidence is not well known currently. From the files of the Nephrology and Cardiology Departments of University Hospital "12 de Octubre" of Madrid, we obtained clinical data from 1612 transplanted patients and only found 2 cases of posttransplant PCLs, both were T-cell PCL. We reviewed the clinical, histopathological, and immunohistochemical characteristics; both cases were T-cell posttransplant PCLs manifested clinically as mycosis fungoides. One was a 57-year-old woman who had received a cadaveric kidney transplant, and the other was a 60-year-old man with a heart transplant. Histology and immunohistochemistry were consistent with the features of mycosis fungoides when lesions were completely developed. Up to 20% of all organ transplant recipients will suffer some form of malignancy. Unlike general population, 70% of PCLs in transplant recipients are B cell in origin and frequently show positivity for Epstein-Barr virus markers; whereas only 30% are cutaneous T-cell lymphomas. Different pathogenic hypothesis including reduced immune surveillance, chronic antigenic stimulation by transplant grafts, and the direct oncogenic effects of immunosuppressive drugs have been suggested. Although cutaneous B-cell lymphomas are more common, dermatopathologists should be aware that cutaneous T-cell lymphomas may also appear.

On reversing the persistence of memory: hematopoietic stem cell transplant for autoimmune disease in the first ten years.

There has been a remarkable history in the treatment of patients with autoimmune disease in the last century. Prior to the development of newer NSAIDs and corticosteroids, the care of patients with autoimmune disease was limited to aspirin and generally homeopathic therapies such as paraffin. In the last 30 years, the introduction and acceptance of cytotoxic drugs such as methotrexate and cyclophosphamide have greatly advanced the treatment of patients with severe autoimmune diseases. However, the use and dose escalation of cytotoxic agents in severely ill patients is limited by toxicity and the potential for secondary malignancies that correlate with cumulative lifetime dosing. As hematopoietic stem cell transplant grew to become an established procedure for certain malignancies, reports of remission of coexistent autoimmune diseases began to emerge. Animal data subsequently supported a role for hematopoietic stem cell transplants for the primary indication of autoimmune diseases. On the basis of these reports, clinical trials of hematopoietic stem cell transplants for the primary indication of autoimmune disease were initiated in the late 1990s. We review the data from a decade of experience that has now accumulated for this novel approach to the management of autoimmunity.

Hepatocyte transplantation for glycogen storage disease type Ib.

Glycogen storage disease type I (GSD-I) is a group of autosomal recessive disorders with an incidence of 1 in 100,000. The two major subtypes are GSD-Ia, caused by a deficiency of glucose-6-phosphatase (G6Pase), and GSD-Ib, caused by a deficiency of glucose-6-phosphate transporter (G6PT). We report that a substantial improvement was achieved following several infusions of hepatocytes in a patient with GSD-Ib. Hepatocytes were isolated from the unused cadaveric whole livers of two donors. At the first transplantation, approximately 2 x 10(9) cells (2% of the estimated recipient's total hepatocytes) were infused. Seven days later 1 x 10(9) (1% of liver mass) cryopreserved hepatocytes from the same donor were infused, and an additional 3 x 10(9) (3% of liver mass) cells from the second donor were infused 1 month after the second transplantation. After the hepatocyte transplantation, the patient showed no hypoglycemic symptoms despite the discontinuation of cornstarch meals. Liver biopsies on posttransplantation days 20 and 250 showed a normal level of glucose-6-phosphatase activity in presolubilization assay that was very low before transplantation. This was the first and successful clinical hepatocyte transplantation in Korea. In this study, hepatocyte transplantation allowed a normal diet in a patient with GSD-Ib, with substantial improvement in their quality of life. Hepatocyte transplantation might be an alternative to liver transplantation and dietary therapy in GSD-Ib.