Differentiation of regulatory myeloid and T-cells from adult human hematopoietic stem cells after allogeneic stimulation.

Introduction: Donor hematopoietic stem cell (DHSC) infusions are increasingly being studied in transplant patients for tolerance induction.

Methods: To analyze the fate of infused DHSCs in patients, we developed an culture system utilizing CD34DHSCs stimulated with irradiated allogeneic cells in cytokine supplemented medium long-term.

Results: Flow cytometric analyses revealed loss of the CD34 marker and an increase in CD33 myeloid and CD3 T-cell proportion by 10.

Does phosphorus influence performance of a native hemiparasite and its impact on a native legume?

Phosphorus (P) is an essential plant nutrient and can become limiting in terrestrial ecosystems where parasitic plant:host associations occur. Yet little is known on how P availability influences parasite performance and its impact on hosts. We investigated the performance of the Australian native stem hemiparasite Cassytha pubescens and its impact on the native leguminous shrub Acacia paradoxa in high or low P conditions in a glasshouse experiment.

The combined effects of water and nitrogen on the relationship between a native hemiparasite and its invasive host.

Stem hemiparasites are dependent on their hosts for water and nitrogen. Most studies, however, have assessed the influence of one factor on parasite : host associations, thus limiting our mechanistic understanding of their performance in nature. We investigated the combined effects of water and nitrogen (N) availability on both a host (Ulex europaeus) and its parasite (Cassytha pubescens).

The impact of a native hemiparasite on a major invasive shrub is affected by host size at time of infection.

Many studies have investigated the effect of parasitic plants on their hosts; however, few have examined how parasite impact is affected by host size. In a glasshouse experiment, we investigated the impact of the Australian native hemiparasitic vine, Cassytha pubescens, on a major invasive shrub, Ulex europaeus, of different sizes. Infected plants had significantly lower total, shoot, and root biomass, but the parasite's impact was more severe on small than on large hosts.

A native parasitic plant affects the performance of an introduced host regardless of environmental variation across field sites.

Increasing evidence from glasshouse studies shows that native hemiparasitic plants can significantly impact the performance and growth of introduced host plants. We investigated the effect of the native Australian hemiparasite Cassytha pubescens R.Br.

Does nitrogen affect the interaction between a native hemiparasite and its native or introduced leguminous hosts?

Associations between plants and nitrogen (N)-fixing rhizobia intensify with decreasing N supply and come at a carbon cost to the host. However, what additional impact parasitic plants have on their leguminous hosts' carbon budget in terms of effects on host physiology and growth is unknown. Under glasshouse conditions, Ulex europaeus and Acacia paradoxa either uninfected or infected with the hemiparasite Cassytha pubescens were supplied (high nitrogen (HN)) or not (low nitrogen (LN)) with extra N.

Does light influence the relationship between a native stem hemiparasite and a native or introduced host?

Background And Aims: There have been very few studies investigating the influence of light on the effects of hemiparasitic plants on their hosts, despite the fact that hemiparasites are capable of photosynthesis but also access carbon (C) from their host. In this study we manipulated light availability to limit photosynthesis in an established hemiparasite and its hosts, and determined whether this affected the parasite's impact on growth and performance of two different hosts. We expected that limiting light and reducing autotrophic C gain in the parasite (and possibly increasing its heterotrophic C gain) would lead to an increased impact on host growth and/or host photosynthesis in plants grown in low (LL) relative to high light (HL).

High water availability increases the negative impact of a native hemiparasite on its non-native host.

Environmental factors alter the impacts of parasitic plants on their hosts. However, there have been no controlled studies on how water availability modulates stem hemiparasites' effects on hosts. A glasshouse experiment was conducted to investigate the association between the Australian native stem hemiparasite Cassytha pubescens and the introduced host Ulex europaeus under high (HW) and low (LW) water supply.

Native hemiparasite and light effects on photoprotection and photodamage in a native host.

Plants infected with hemiparasites often have lowered rates of photosynthesis, which could make them more susceptible to photodamage. However, it is also possible that infected plants increase their photoprotective capacity by changing their pigment content and/or engagement of the xanthophyll cycle. There are no published studies investigating infection effects on host pigment dynamics and how this relates to host susceptibility to photodamage whether in high (HL) or low light (LL).

Inhibition of NF-kappa B during human dendritic cell differentiation generates anergy and regulatory T-cell activity for one but not two human leukocyte antigen DR mismatches.

We examined the in vitro inhibition of human monocyte-derived dendritic cells (DC) maturation via NF-kappaB blockade on T-cell allostimulation, cytokine production, and regulatory T-cell generation. DC were generated from CD14+ monocytes isolated from peripheral blood using GM-CSF and IL-4 for differentiation and TNF-alpha, IL-1beta, and PGE2 as maturational stimuli with or without the NF-kappaB inhibitors, BAY 11-7082 (BAY-DC) or Aspirin (ASA-DC). Stimulator and responder cells were one versus two HLA-DR mismatched in direct versus indirect presentation assays.

FoxP3 mRNA transcripts and regulatory cells in renal transplant recipients 10 years after donor marrow infusion.

Background: We update more favorable 10-year deceased donor kidney transplant survival in 63 recipients infused perioperatively with donor vertebral body bone marrow (DBMC-i) vs. 219 noninfused controls having equivalent immunosuppression and demographics. We questioned if this was associated with putatively regulatory FoxP3 mRNA and cell phenotypes (CD4+CD25+high percentages and high DC2:DC1 ratios) in DBMC-i vs.

A novel approach to detect donor/recipent immune responses between HLA-identical pairs.

Renal transplant rejection and graft versus host reactions between HLA genetically-identical sibling (HLAgi) donor/recipient (D/R) pairs are thought to result from minor histocompatibility antigen (mHAg) disparities. We have compared two methods of measuring HLAgi D/R T lymphocyte responses to "matured" dendritic cells: 1.) a modified Cylex assay of CD4(+) ATP levels (MLDC-ATP) versus 2.

A randomized trial of three renal transplant induction antibodies: early comparison of tacrolimus, mycophenolate mofetil, and steroid dosing, and newer immune-monitoring.

Background: New trends in immunosuppression in clinical transplantation include the use of antibody induction agents in protocols that emphasize reduction or avoidance of steroids and calcineurin inhibitors.

Methods: In a randomized trial using three different antibody induction agents in 90 first renal transplant recipients from cadaver donors, group A received Thymoglobulin, group B received Alemtuzumab, and group C received Daclizumab. Maintenance immunosuppression included tacrolimus and mycophenolate in all three arms, and methylprednisolone in groups A and C only (standard clinical institutional practice).

Cytomegalovirus prophylaxis with valganciclovir in kidney, pancreas-kidney, and pancreas transplantation.

Cytomegalovirus, seen in more than 50% of solid organ transplant recipients, is responsible for numerous direct and indirect consequences, including infection with opportunistic pathogens and allograft rejection. Prophylaxis with intravenous ganciclovir has been the gold standard for prevention; however, intravenous treatment is expensive and carries risks of its own. Oral ganciclovir, to be effective, must be given in large, divided doses.

Prediction of sustained virological response in liver transplant recipients with recurrent hepatitis C virus following combination pegylated interferon alfa-2b and ribavirin therapy using tissue hepatitis C virus reverse transcriptase polymerase chain reaction testing.

The optimal duration of therapy for pegylated interferon combined with ribavirin in recurrent Hepatitis C virus (HCV) following liver transplantation is not known. We wanted to determine if testing for HCV in liver tissue by reverse transcriptase polymerase chain reaction (RT-PCR) was superior in predicting sustained virological response (SVR) in comparison to standard HCV ribonucleic acid (RNA) detection in the serum. All recipients received combination pegylated alpha-2b interferon (1.

Immune responses and their regulation by donor bone marrow cells in clinical organ transplantation.

Infusions of donor bone marrow derived cells (DBMC) continue to be tested in clinical protocols intended to induce specific immunologic tolerance of solid organ transplants based on the observations that donor-specific tolerance is induced this way in animal models. We studied the immunological effects of human DBMC infusions in renal transplantation using modifications in lymphoproliferation (MLR) and cytotoxicity (CML) assays. The salient observations and tentative conclusions are summarized in this review.

Use of liver grafts from donors positive for antihepatitis B-core antibody (anti-HBc) in the era of prophylaxis with hepatitis-B immunoglobulin and lamivudine.

Background: The increasing demand for transplantation has resulted in a trend toward using virologically compromised donors. We reviewed our experience with liver grafts from hepatitis-B surface antigen (HBsAg)(-), antibody to core antigen (anti-HBc)(+) donors.

Methods: Sixty-two liver transplants using HBsAg(-), anti-HBc(+) donors were studied.

Adenovirus infection in pediatric liver and intestinal transplant recipients: utility of DNA detection by PCR.

To evaluate the incidence of adenovirus (AdV) infection in pediatric liver and intestinal transplant recipients, the records of patients with possible AdV infection were reviewed for demographic data, symptomatology, methods of diagnosis, treatment and outcome. To evaluate the impact of polymerase chain reaction (PCR) amplification and identification of AdV DNA as a diagnostic test, the incidence and outcome of AdV before and after the introduction of PCR were compared. Adenovirus infection was identified in 4.

Successful treatment of posttransplant lymphoproliferative disease with prolonged rituximab treatment in intestinal transplant recipients.

Background: Posttransplant Epstein-Barr virus-associated B-cell lymphoproliferative disease (PTLD) has a higher incidence after intestinal transplantation than after transplantation of other solid organs and is associated with a high mortality. A new anti-CD20 monoclonal antibody, rituximab, has shown efficiency in the treatment of B-cell lymphoma, including PTLD, but its use has not yet been reported in intestinal transplant recipients.

Methods: We retrospectively reviewed five patients who were diagnosed with PTLD from March 1999 to August 2001, after intestinal transplantation.