Cytokine and chemokine profiles in autologous graft-versus-host disease (GVHD): interleukin 10 and interferon gamma may be critical mediators for the development of autologous GVHD

Pathophysiology and preclinical relevance of experimental graft-versus-host disease in humanized mice

Graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantations (allo-HCT) used for the treatment of hematological malignancies and other blood-related disorders. Until recently, the discovery of actionable molecular targets to treat GVHD and their preclinical testing was almost exclusively based on modeling allo-HCT in mice by transplanting bone marrow and splenocytes from donor mice into MHC-mismatched recipient animals. However, due to fundamental differences between human and mouse immunology, the translation of these molecular targets into the clinic can be limited. Therefore, humanized mouse models of GVHD were developed to circumvent this limitation. In these models, following the transplantation of human peripheral blood mononuclear cells (PBMCs) into immunodeficient mice, T cells recognize and attack mouse organs, inducing GVHD. Thereby, humanized mice provide a platform for the evaluation of the effects of candidate therapies on GVHD mediated by human immune cells in vivo. Understanding the pathophysiology of this xenogeneic GVHD is therefore crucial for the design and interpretation of experiments performed with this model. In this article, we comprehensively review the cellular and molecular mechanisms governing GVHD in the most commonly used model of xenogeneic GVHD: PBMC-engrafted NOD/LtSz-PrkdcscidIL2rγtm1Wjl (NSG) mice. By re-analyzing public sequencing data, we also show that the clonal expansion and the transcriptional program of T cells in humanized mice closely reflect those in humans. Finally, we highlight the strengths and limitations of this model, as well as arguments in favor of its biological relevance for studying T-cell reactions against healthy tissues or cancer cells.

Interleukin-10 GCC/GCC haplotype is associated high risk of acute GVHD in patients undergoing allogeneic HSCT in the southern of Brazil

INTRODUCTION

Hematopoietic Stem Cell Transplant (HSCT) is currently an important curative treatment for many patients with malignant and non-malignant diseases. Graft versus host disease (GVHD) represents a major complication in allogeneic HSCT recipients. Several polymorphisms in cytokine genes have recently been investigated as candidates for risk factors for acute-GVHD (aGVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT).

OBJECTIVE

In this study, we analyzed specific interleukin (IL)-10 haplotypes polymorphisms, in a cohort of 99 patients and their respective allo-HSCT donors for aGVHD and risk.

RESULTS

An association was found between IL-10 promoter haplotype polymorphisms at positions -1082, -819 and - 592 with the occurrence of aGVHD. Patients who have the GCC/GCC haplotype are at increased risk of aGVHD (P = 0.017, HR: 5.42 (95% CI: 1.34-21.84). In the donors group and severity of aGVHD as not found statistical significancy.

CONCLUSION

The results obtained show the IL-10 GCC/GCC haplotype can be an important biomarker to identify the greatest risk of aGVHD in the patient undergoing HSCT.

Hepatic graft-versus-host disease: what we know, when to biopsy, and how to diagnose

Graft-versus-host disease (GVHD) is one of the serious complications that may develop after hematopoietic cell transplantation (HCT), for hematologic malignancies, solid organ transplantation, and other hematologic disorders. GVHD develops due to T lymphocytes present in the graft attacking the host antigens, which results in tissue damage. A significant number of HCT patients develop acute or chronic GVHD, which may affect multiple organs including the liver. The diagnosis of hepatic GVHD (hGVHD) is challenging as many other conditions in HCT patients may lead to liver dysfunction. Particularly challenging among the various conditions that give rise to liver dysfunction is differentiating sinusoidal obstruction syndrome and drug-induced liver injury (DILI) from hGVHD on clinical grounds and laboratory tests. Despite the minimal risks involved in performing a liver biopsy, the information gleaned from the histopathologic changes may help in the management of these very complex patients. There is a spectrum of histologic features found in hGVHD, and most involve histopathologic changes affecting the interlobular bile ducts. These include nuclear and cytoplasmic abnormalities including dysmorphic bile ducts, apoptosis, and cholangiocyte necrosis, among others. The hepatitic form of hGVHD typically shows severe acute hepatitis. With chronic hGVHD, there is progressive bile duct loss and eventually fibrosis. Accurate diagnosis of hGVHD is paramount so that timely treatment and management can be initiated. Techniques to prevent and lower the risk of GVHD from developing have recently evolved. If a diagnosis of acute GVHD is made, the first-line of treatment is steroids. Recurrence is common and steroid resistance or dependency is not unusual in this setting. Second-line therapies differ among institutions and have not been uniformly established. The development of GVHD, particularly hGVHD, is associated with increased morbidity and mortality.

Regulatory B Cells in Autoimmune Diabetes

Since they were discovered almost three decades ago, a subset of B cells denoted as regulatory B cells (Bregs) have elicited interest throughout the immunology community. Many investigators have sought to characterize their phenotype and to understand their function and immunosuppressive mechanisms. Indeed, studies in murine models have demonstrated that Bregs possess varied phenotypic markers and could be classified into different subsets whose action and pivotal role depend on the pathological condition or stimuli. Similar conclusions were drawn in clinical settings delineating an analogous Breg population phenotypically resembling the murine Bregs that ultimately may be associated with a state of tolerance. Recent studies suggested that Bregs may play a role in the onset of autoimmune diabetes. This review will focus on deciphering the different subclasses of Bregs, their emerging role in autoimmune diabetes, and their potential use as a cell-based therapeutic.

The effects of gene polymorphisms on susceptibility to acute GVHD and survival of allogeneic HSCT recipients: IL-10 gene polymorphisms as a more accessible target to predict prognosis

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a therapeutic modality commonly used to treat hematological and immunological disorders. Among the main complications of allo-HSCT is the acute graft-versus-host disease (a-GVHD), a condition which accounts for a high incidence of mortality. Several genes encoding inflammatory mediators may present polymorphisms, which have been implicated in the risk of developing a-GVHD. In our study, we investigated the association between genotypes of cytokine-encoding genes and the incidence and severity of a-GVHD and survival of HSCT recipients. No statistically significant association was found between IL and 6-174 G/C, INF-γ + 874 T/A, TNF-α -238 A/G, -308 A/G and IL-10-819C/T, -592 A/C polymorphisms and the presence or severity of a-GVHD. A higher risk of a-GVHD was associated with the IL-10-1082 GG genotype compared to the AA + AG genotypes of recipients and donors. The IL-10-1082 genotype can be used as a prognostic determinant to predict which HSCT recipient will be more responsive to the transplant. Thus, cytokine gene assays may be useful in the individualization of prophylactic regimens and for an appropriate selection of immunosuppressants based on the HSCT recipient's responsiveness.

Induced pluripotent stem cell-derived mesenchymal stem cells prolong hind limb survival in a rat vascularized composite allotransplantation model

BACKGROUND

The reduction of systemic immunosuppressive agents is essential for the expansion of vascularized composite allotransplantation (VCA) in a clinical setting. The purpose of this study is to compare human-induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs) with four other types of mesenchymal stem cells (human bone marrow-derived MSCs [BMMSCs], human adipose-derived MSCs [ADMSCs], rat BMMSCs, and rat ADMSCs) in vitro, and to investigate the in vivo immunomodulatory effect of iMSCs in a rat VCA model.

MATERIALS AND METHODS

One Brown Norway (BN) rat, 2 Lewis (LEW) rats, and 1 Wistar rat were used in the mixed lymphocyte reaction (MLR), and 9 BN rats and 3 LEW rats (for donors), and 24 LEW rats (for recipients) were used in the VCA model. The abovementioned five types of MSCs were imaged to examine their morphology and were also tested for suppressor function using a MLR. The 24 recipient LEW rats were divided randomly into four groups, and subjected to orthotopic hind limb transplantation. The three control groups were the Iso group, in which transplantation was performed on from three to six LEW rats without immunosuppressive treatment (n = 6); the FK group, in which transplantation was performed from BN rats to LEW rats and recipient rats were treated with tacrolimus alone (FK 506, 0.2 mg/kg, days 0-6 postoperatively, intraperitoneally) (n = 6); and the UT group, in which transplantation was performed from BN rats to LEW rats without any immunosuppressive treatment (n = 6). The experimental group was the iMSC group, in which transplantation was performed from BN rats to LEW rats and recipient rats were treated with tacrolimus (FK 506, 0.2 mg/kg, days 0-6 postoperatively, intraperitoneally) and injected with iMSCs (2 × 10⁶ cells, day 7, intravenously) (n = 6). Hind limb survival was assessed by daily inspection of gross appearance until 50 days postoperatively. Histology of the skin and muscle biopsy were investigated on day 14 postoperatively. A time series of the plasma cytokine level (before transplantation, and at 10, 14, and 17 days after transplantation) was also analyzed.

RESULTS

The size of adherent and trypsinized iMSCs was 67.5 ± 8.7 and 9.5 ± 1.1 μm, respectively, which was the smallest among the five types of MSCs (p < .01). The absorbance in MLR was significantly smaller with rat ADMSCs (p = .0001), human iMSCs (p = .0006), rat BMMSCs (p = .0014), human ADMSCs (p = .0039), and human BMMSCs (p = .1191) compared to without MSCs. In vivo, iMSC treatment prolonged hind limb survival up to 12.7 days in macroscopic appearance, which is significantly longer than that of the FK group (p < .01). Histology of the skin and muscle biopsy revealed that mononuclear cell infiltration was significantly reduced by iMSC injection (p < .01). iMSC treatment also affected proinflammatory cytokines (interferon-gamma (IFNγ) and tumor necrosis factor α (TNFα)) and the anti-inflammatory cytokine (interleukin-10 (IL-10)) of the recipient plasma. The IFNγ levels at Δ14 and the TNFα levels at Δ14 and Δ17 of the iMSC group were significantly lower than those of the FK group (p = .0226, .0004, and .004, respectively). The IL-10 levels at Δ10 and Δ14 of the iMSC group were significantly higher than those of the FK group (p = .0013 and .0374, respectively).

CONCLUSIONS

iMSCs induce T cell hyporesponsiveness to prolong hind limb survival in a rat VCA model. This immunomodulatory property against acute rejection could provide one of the promising strategies capable of enabling the toxicities of immunosuppressants to be avoided in clinical settings.

Autograft immune effector cells and survival in autologous peripheral blood hematopoietic stem cell transplantation

In addition to stem cells, T-cells, natural killer cells, dendritic cells, and monocytes are also collected and infused from the autograft in patients undergoing autologous peripheral blood hematopoietic stem cell transplantation. Recent reports have shown that these autograft immune effector cells can affect the clinical outcome postautologous peripheral blood hematopoietic stem cell transplantation. In this article, I will review the clinical impact on the survival of these autograft immune effector cells conferring the concept of autologous graft versus tumor effect.

Combination of IL-10 and IL-2 induces oligoclonal human CD4 T cell expansion during xenogeneic and allogeneic GVHD in humanized mice

IL-10 is a crucial anti-inflammatory cytokine which can also exert a seemingly divergent immunostimulatory effects under certain conditions. We found high levels of the cytokine in a xenogeneic GVHD model where NOD-scid IL2rγcnull (NSG) mice were transplanted with human PBMCs in presence of IL-2. Presence of exogenous IL-10 altered the kinetics of IL-2 induced human T cell reconstitution in vivo, showing an initial delay, followed by rapid expansion. Further, compared to IL-2 alone, treatment with IL-2 in combination with IL-10 increased survival in most animals and completely protected ∼20% of mice from GVHD. Additionally, IL-2 induced expansion of both CD4⁺ and CD8⁺ xenoreactive T cells whereas a combination of IL-2 and IL-10 resulted in selective expansion of CD4⁺ T cells only. TCR Vβ repertoire analysis of CD4⁺ T cells showed that in contrast to IL-2 alone, simultaneous presence of both cytokines drastically reduced the Vβ repertoire of the expanded CD4⁺ T cells. Highly restricted Vβ usage was also observed when the cytokine combination was tested in an allogeneic GVHD model where NOD-scid IL2rγc^null mice expressing HLA-DR4 (NSG-DR4) were transplanted with purified CD4⁺ T cells from HLA-DR4 negative donors. Taken together, our results demonstrate that IL-10 can profoundly modulate the subset composition and repertoire of responding T cells during GVHD.

Acute graft-versus-host disease and bronchiolitis obliterans after autologous stem cell transplantation in a patient with multiple myeloma

Sixty-seven-year-old patient, diagnosed with multiple myeloma who had received autologous stem cell transplantation, following bortezomib, dexamethasone and thalidomide conventional regimen, achieving complete response, developed rash, diarrhea, and severe respiratory failure, 80 days after the transplantation procedure. He was diagnosed with graft-versus-host disease and bronchiolitis obliterans syndrome.

IL-10 exacerbates xenogeneic GVHD by inducing massive human T cell expansion

Although patients with GVHD have elevated serum levels of IL10, whether its role is protective or pathogenic remains unclear. Here, we used a humanized mouse model to study the role of IL-10 in GVHD. When human PBMCs were engrafted in NOD-scid IL2rγc(null) mice expressing human IL-10, the T cells underwent massive expansion resulting in lethality by day 21, whereas control mice survived for at least 40 days. Histopathology of the liver showed extensive mononuclear cell infiltration in IL-10 expressing but not in control mice. Corresponding to their aggressiveness, the T cells in the IL-10 group exhibited predominantly an effector memory phenotype (CD45RO(+)CD27(-)) while in control mice, the T cells were of transitional memory phenotype (CD45RO(+)CD27(+)). Further, IL-10 receptor blocking antibody was able to protect the animals from GVHD. Since our results demonstrate a direct pathogenic role for IL-10, blockade of IL-10 signaling may provide a therapeutic option for GVHD.

Harnessing the power of alloreactivity without triggering graft-versus-host disease: how non-engrafting alloreactive cellular therapy might change the landscape of acute myeloid leukemia treatment

Human leukocyte antigen-mismatched leukocyte infusions outside of the context of transplantation are a promising strategy for acute myeloid leukemia. Recent studies using such non-engrafting alloreactive cellular therapy (NEACT) revealed that survival of elderly patients increased from 10% to 39% when NEACT was given following chemotherapy, and that durable complete remissions were achieved in about a third of patients with relapsed or chemorefractory disease. We review the clinical reports of different NEACT approaches to date and describe how although T-cell and NK alloreactivity could generate immediate anti-leukemic effects, long-term disease control may be achieved by stimulating recipient-derived T-cell responses against tumor-associated antigens. Other variables likely impacting NEACT such as the release of pro-inflammatory cytokines from donor-host bidirectional alloreactivity and the choice of chemotherapeutics as well as future avenues for improving NEACT, such as optimizing the cell dose and potential synergies with adjuvant pharmacologic immune checkpoint blockade, are discussed.

Polymorphisms in the TNF-α and IL-10 gene promoters and risk of psoriasis and correlation with disease severity

Several cytokines were assumed to play an essential role in the induction and the pathogenesis of psoriasis. The aim of this work was to investigate the role of TNF-α-308 and IL-10-1082 polymorphisms and their serum levels in the pathogenesis of psoriasis and determine their relation to disease severity. 110 Psoriasis patients and 120 healthy volunteers were genotyped for TNF-α-308 and IL-10-1082 polymorphism by polymerase chain reaction. Serum level of TNF-α and IL-10 were measured by ELISA. Our study demonstrated an association of IL-10-1082 polymorphism and psoriasis and between TNF α-308 polymorphism and psoriasis disease and severity. Serum TNF α increased in patients, while serum IL-10 decreased in patients with significant correlation between serum TNF-α and psoriasis severity. These results indicated that TNF-α-308 and IL-10-1082 polymorphisms imparted significant risk towards the development of psoriasis.

DNA methylation dynamics in blood after hematopoietic cell transplant

Epigenetic deregulation is considered a common hallmark of cancer. Nevertheless, recent publications have demonstrated its association with a large array of human diseases. Here, we explore the DNA methylation dynamics in blood samples during hematopoietic cell transplant and how they are affected by pathophysiological events during transplant evolution. We analyzed global DNA methylation in a cohort of 47 patients with allogenic transplant up to 12 months post-transplant. Recipients stably maintained the donor’s global methylation levels after transplant. Nonetheless, global methylation is affected by chimerism status. Methylation analysis of promoters revealed that methylation in more than 200 genes is altered 1 month post-transplant when compared with non-pathological methylation levels in the donor. This number decreased by 6 months post-transplant. Finally, we analyzed methylation in IFN-γ, FASL, IL-10, and PRF1 and found association with the severity of the acute graft-versus-host disease. Our results provide strong evidence that methylation changes in blood are linked to underlying physiological events and demonstrate that DNA methylation analysis is a viable strategy for the study of transplantation and for development of biomarkers.

Kinetics of T helper subsets and associated cytokines correlate well with the clinical activity of graft-versus-host disease

Background

CD4⁺interferon (IFN)-γ⁺ T cell (Th1) and CD4⁺interleukin (IL)-4⁺ T cell (Th2) polarizations are crucial in the pathogenesis of graft-versus-host disease (GVHD). However, this hypothesis is largely based on animal experiments of Parent-into-F1 GVHD model. The causal relationship between kinetics of Th1, Th2 and associated cytokines and the clinical activity of GVHD in a real world situation remains unknown.

Methodology

Peripheral blood was collected every week prospectively from Day 0 to Day 210 (patients without GVHD) or Day 300 (patients with chronic GVHD) after allogeneic peripheral blood stem cell transplantation in consecutive 27 patients. The frequencies of Th1 and Th2 within CD4⁺ T cells were determined by flow cytometry and pplasma IFN-γ, IL-12, IL-4, and IL-10 were determined by ELISA.

Principal Findings

Kinetics of Th1, Th2 frequency, and the plasma IL-10 and IFN-γ more commonly coincided with, rather than predicted, the activity of GVHD. These markers are significantly higher when acute or chronic GVHD developed. The kinetics of IL-10 is especially correlated well with the activity of GVHD during clinical course of immunosuppressive treatment. For patients with hepatic GVHD, there is a positive correlation between plasma IL-10 levels and the severity of hepatic injury. The frequency of Th2 is also significant higher in acute GVHD and tends to be higher in chronic GVHD. Interestingly, there is a very good positive correlation between the frequency of Th1 and Th2 (r = 0.951, p<0.001). The plasma level of IL-4 and IL-12 are not associated with the activity of GVHD.

Conclusions

The frequency of Th1, Th2 within CD4⁺ T cells and plasma IL-10 and IFN-γ are good biomarkers of GVHD. Plasma IL-10 can also be used to monitor the therapeutic responsiveness. Furthermore, both Th1 and Th2 likely contribute to the pathogenesis of GVHD.

Treatment of whole blood with riboflavin plus ultraviolet light, an alternative to gamma irradiation in the prevention of transfusion-associated graft-versus-host disease?

BACKGROUND

Exposure of blood products to gamma irradiation is currently the standard of care in the prevention of transfusion-associated graft-versus-host disease (TA-GVHD). Regulatory, technical, and clinical challenges associated with the use of gamma irradiators are driving efforts to develop alternatives. Pathogen reduction methods were initially developed to reduce the risk of microbial transmission by blood components. Through modifications of nucleic acids, these technologies interfere with the replication of both pathogens and white blood cells (WBCs). To date, systems for pathogen and WBC inactivation of products containing red blood cells are less well established than those for platelets and plasma.

STUDY DESIGN AND METHODS

In this study, the in vitro and in vivo function of WBCs present in whole blood after exposure to riboflavin plus ultraviolet light (Rb-UV) was examined and compared to responses of WBCs obtained from untreated or gamma-irradiated blood by measuring proliferation, cytokine production, activation, and antigen presentation and xenogeneic (X-)GVHD responses in an in vivo mouse model.

RESULTS

In vitro studies demonstrated that treatment of whole blood with Rb-UV was as effective as gamma irradiation in preventing WBC proliferation, but was more effective in preventing antigen presentation, cytokine production, and T-cell activation. Consistent with in vitro findings, treatment with Rb-UV was as effective as gamma irradiation in preventing X-GVHD, a mouse model for TA-GVHD.

CONCLUSION

The ability to effectively inactivate WBCs in fresh whole blood using Rb-UV, prior to separation into components, provides the transfusion medicine community with a potential alternative to gamma irradiation.

Donor- but not host-derived interleukin-10 contributes to the regulation of experimental graft-versus-host disease

IL-10 is a key immune-regulatory cytokine, and its gene polymorphisms correlate with severity of clinical GVHD. IL-10 is made by a variety of donor and host cells, but the functional relevance of its source and its role in the biology of acute GVHD are not well understood. We used preclinical models to examine the relevance of IL-10(-/-) in donor and host cellular subsets on the severity of GVHD. IL-10(-/-) in host tissues or in the donor grafts did not alter donor Teff-mediated severity of GVHD. Furthermore, neither host-derived nor donor Teff-derived IL-10 was required for regulation of GVHD by WT CD4(+)CD25(+) donor Tregs. By contrast, Treg-derived IL-10, although not obligatory, was necessary for optimal reduction of GVHD by mature donor Tregs. Importantly, IL-10 from donor BM grafts was also critical for optimal donor Treg-mediated suppression of GVHD. Together, these data suggest that IL-10 does not contribute to the induction of GVHD severity by the Teffs. However, donor BM graft and Treg-derived IL-10 are important for donor Treg-mediated suppression of GVHD.

Korean red ginseng: a new approach for the treatment of graft-versus-host disease after liver transplantation

BACKGROUND

Graft-versus-host disease (GVHD) is a rare complication after liver transplantation with an extremely poor prognosis; its occurrence offers great challenges.

METHODS

We have reported herein one case of acute GVHD after liver transplantation who was treated with a traditional Chinese medicine named Korean Red Ginseng (KRG).

RESULTS

The acute GVHD was successfully cured by KRG.

CONCLUSIONS

The successful salvage of acute GVHD after liver transplantation by KRG may provide a new viable therapeutic option.

Atypical diabetes mellitus associated with bone marrow transplantation

OBJECTIVE

To describe 3 cases of atypical diabetes mellitus following bone marrow transplantation.

METHODS

We describe the clinical presentation and relevant laboratory findings of 3 patients who presented with new-onset diabetes mellitus after bone marrow transplantation and discuss the possible mechanisms.

RESULTS

A 52-year-old white man with chronic myelogenous leukemia, a 51-year-old white woman with acute myelogenous leukemia, and a 38-year-old Hispanic woman with acute myelogenous leukemia presented with acute onset of diabetes mellitus after bone marrow transplantation. Although blood glucose levels were initially very high, the patients required only small insulin dosages for glycemic control. Both the acute onset and requirement of relatively small insulin dosages were characteristic of type 1 diabetes mellitus. Onset of diabetes appeared to be unrelated to immunosuppressive drug therapy because it happened several months after starting these drugs. C-peptide was detectable, and glutamic acid decarboxylase antibodies were absent. Diabetes mellitus remitted spontaneously after a few months while the immunosuppressive drugs were continued.

CONCLUSION

Although the underlying mechanisms are unknown, cytokine changes after bone marrow transplantation may have led to temporary beta-cell dysfunction in these patients.

Immuno-modulatory gene polymorphisms and outcome in breast and ovarian cancer

Breast and ovarian cancer continue to be a significant source of morbidity and mortality. Improved understanding of signalling pathways related to growth and apoptosis has led to targeted treatments and modest improvement in long term outcomes. However, it has become increasingly clear that tumor factors alone are not the sole determinants of outcome in patients with breast and ovarian cancer. The tumor microenvironment and other immunologic host processes play an integral role in the overall interactions between disease, host and treatment. Cytokines play a major role in the immune response to tumors. Single nucleotide polymorphisms (SNPs) in the regulatory or coding regions of many cytokine genes lead to functional alterations in the transcriptional regulation of these genes or the proteins they encode. This review examines the current literature linking functional variants in cytokine and other immune genes to outcomes in breast and ovarian cancer. We have focused on those involved in the proinflammatory response (IL-6, TNF-alpha), apoptosis (TGF-beta, Fas, FasL, C1QA), angiogenesis (IL-8) and autoimmunity (IL-10). While much remains to be learned about the mechanisms underlying these variants and their impact on tumor behavior, this area holds promise for future development of prognostic profiles and therapeutics exploiting the immune response.

IL10 and IL10 receptor gene variation and outcomes after unrelated and related hematopoietic cell transplantation

BACKGROUND

Results of a previous study with human leukocyte antigen (HLA)-identical siblings showed individual and synergistic associations of single nucleotide polymorphisms in the promoter region of the recipient's IL10 gene and the donor's IL10 receptor beta (IL-10RB) gene with development of grades III-IV acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation.

METHODS

In this study of 936 patients who had unrelated donors, genotypes of single nucleotide polymorphisms in the IL10 gene and the IL-10RB gene were evaluated as correlates with outcomes after transplantation.

RESULTS

We found no statistically significant associations of polymorphisms at positions -3575, -2763, -1082, and -592 of the IL10 gene or codon 238 of the IL10RB gene with severe acute GVHD, extensive chronic GVHD or nonrelapse mortality after hematopoietic cell transplantation. Among HLA-matched unrelated pairs, the patient's IL10/-592 genotype and donor's IL10RB/c238 genotype showed trends suggesting individual and combined associations with grades III-IV acute GVHD similar to those observed among patients with HLA-identical sibling donors.

CONCLUSIONS

Although genetic variation in IL10 pathway affects risk of acute GVHD and non-relapse mortality in HLA-identical sibling transplants, the current results indicate that genetic variation in the IL10 pathway does not significant affect these outcomes in unrelated donor transplants suggesting that the strength of the alloimmune response in the latter exceeds the anti-inflammatory activity of IL10.

Expression of T-plastin, FoxP3 and other tumor-associated markers by leukemic T-cells of cutaneous T-cell lymphoma

Peripheral blood cells from 28 patients with leukemic cutaneous T-cell lymphoma including 25 patients with Sezary syndrome were evaluated for expression of regulatory T-cell-associated markers (FoxP3, CD25, CTLA-4, neurophilin-1), T-cell activation markers (CD28 and its ligands B7.1 and B7.2) and NK cell-associated markers (NKG2D and its ligands Mic-A and Mic-B) using real-time quantitative polymerase chain reaction. T-plastin served as a positive genetic marker, and its expression correlated to blood tumor burden. More than 90% of samples had transcripts for CD28 and Mic-B, but less than 30% of samples expressed FoxP3, CTLA-4 and CD25. Expression of Mic-B by neoplastic cells could provide another mechanism to inhibit anti-tumor immune responses. FoxP3 expression correlated with a poor prognosis. Although the underlying mechanisms accounting for this correlation remain unclear, the expression of the Foxp3 and CTLA-4 regulatory elements indicates that a subset of leukemic cases displays a regulatory T-cell phenotype.

Induction of autologous graft-versus-host disease: results of a randomized prospective clinical trial in patients with poor risk lymphoma

The results of blood or marrow transplantation in patients with chemorefractory aggressive lymphoma, that is, those not responding to conventional-dose chemotherapy at the time of transplant, have been poor. The relapse rate has been high after autologous bone marrow transplant, whereas allogeneic transplantation has been associated with excessive transplant-related toxicity. Administration of cyclosporine after autologous transplantation can induce an autoreactive syndrome that resembles graft-versus-host disease (GVHD). This syndrome, named autologous graft-versus-host disease, has clear antitumor activity in animal models that can be enhanced by the addition of cytokines such as gamma-interferon and interleukin-2. A randomized, prospective study was conducted to evaluate the antitumor effect of autologous graft-versus-host disease induced with cyclosporine, and augmented by the administration of gamma-interferon and interleukin-2 in patients with chemorefractory Hodgkin and aggressive non-Hodgkin lymphomas. Fifty-one patients were randomized, 24 to the autologous GVHD induction arm, and 27 to the noninduction arm after autologous transplant using mobilized peripheral blood stem cell (PBSC) grafts. There were no differences in treatment-related mortality, overall and event-free survival (OS, EFS) between both groups; however, in the induction arm, GVHD developed only in 4 patients. The administration of oral cyclosporine followed by interleukin-2 and gamma-interferon is generally not well tolerated, and does not appear to be an effective method to induce autologous GVHD in patients receiving autologous PBSC grafts.

The EP4 receptor antagonist, L-161,982, blocks prostaglandin E2-induced signal transduction and cell proliferation in HCA-7 colon cancer cells

Accumulating evidence indicates that elevated levels of prostaglandin E(2) (PGE(2)) can increase intestinal epithelial cell proliferation, and thus play a role in colorectal tumorigenesis. PGE(2) exerts its effects through four G-protein-coupled PGE receptor (EP) subtypes, named the EP1, EP2, EP3, and EP4. Increased phosphorylation of extracellular regulated kinases (ERK1/2) is required for PGE(2) to stimulate cell proliferation of human colon cancer cells. However, the EP receptor(s) that are involved in this process remain unknown. We provide evidence that L-161,982, a selective EP4 receptor antagonist, completely blocks PGE(2)-induced ERK phosphorylation and cell proliferation of HCA-7 cells. In order to identify downstream target genes of ERK1/2 signaling, we found that PGE(2) induces expression of early growth response gene-1 (EGR-1) downstream of ERK1/2 and regulates its expression at the level of transcription. PGE(2) treatment induces phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 residue and CRE-mediated luciferase activity in HCA-7 cells. Studies with dominant-negative CREB mutant (ACREB) provide clear evidence for the involvement of CREB in PGE(2) driven egr-1 transcription in HCA-7 cells. In conclusion, this study reveals that egr-1 is a target gene of PGE(2) in HCA-7 cells and is regulated via the newly identified EP4/ERK/CREB pathway. Finally our results support the notion that antagonizing EP4 receptors may provide a novel therapeutic approach to the treatment of colon cancer.

Chemokine receptor expression by leukemic T cells of cutaneous T-cell lymphoma: clinical and histopathological correlations

Chemokine receptors expressed by normal and neoplastic lymphocytes provide an important mechanism for cells to traffic into the skin and skin-associated lymph nodes. The goal of this study was to correlate chemokine receptor and CD62L expression by circulating neoplastic T cells with the clinical and pathological findings of the leukemic phase of cutaneous T-cell lymphoma, primarily Sézary syndrome (SS). Chemokine receptor mRNA transcripts were found in the majority of leukemic cells for CCR1, CCR4, CCR7, CCR10, CXCR3, and CD62L and in 20-50% of the samples for CXCR5. In patients with SS, relatively high expression levels of CCR7 and CCR10 by circulating neoplastic T cells correlated with epidermotropism, CXCR5 expression correlated with density of the dermal infiltrate, and CD62L correlated with extent of lymphadenopathy. Of note, CXCR5 expression and a dense dermal infiltrate correlated with a poor prognosis. The chemokine receptor profile supports the concept that neoplastic T cells are central memory T cells, and that CCR10 and CD62L play a fundamental role respectively in epidermotropism and lymphadenopathy that is observed in SS.

Systemic interleukin-2 and adoptive transfer of lymphokine-activated killer cells improves antibody-dependent cellular cytotoxicity in patients with relapsed B-cell lymphoma treated with rituximab

PURPOSE

Murine models have shown that antibody-dependent cellular cytotoxicity (ADCC) can be improved with addition of lymphokine-activated killer (LAK) cells to monoclonal antibodies. A pilot trial of rituximab and LAK cells in patients with rituximab-refractory CD20+ lymphoma was conducted to evaluate this approach.

EXPERIMENTAL DESIGN

Ten patients received 3 million units/m2 of interleukin-2 (IL-2) i.v. qd on days 1 to 5 and leukapheresed on days 8, 9, and 10. The leukapheresis product was cultured with IL-2 for 48 h to produce LAK cells. Patients then received 375 mg/m2 i.v. rituximab and LAK cells on days 10, 11, and 12. The patients also received 3 million units/m2 of IL-2 i.v. for 5 days starting day 10. For safety purposes, the first three patients did not receive any LAK cell infusions.

RESULTS

The LAK cell infusions improved the ADCC activity of peripheral blood lymphocytes compared with pretreatment activity and prevented the decline in ADCC seen after infusion of rituximab alone. Therapy was well tolerated and the most clinically significant toxicities were fever and fatigue. Two patients achieved a partial remission and five had stable disease.

CONCLUSIONS

The results from these studies suggest that the addition of LAK cells to rituximab augments ADCC in patients with rituximab-refractory lymphoma.

Beyond HLA: the significance of genomic variation for allogeneic hematopoietic stem cell transplantation

The last 2 years have seen much excitement in the field of genetics with the identification of a formerly unappreciated level of “structural variation” within the normal human genome. Genetic structural variants include deletions, duplications, and inversions in addition to the recently discovered, copy number variants. Single nucleotide polymorphisms are the most extensively evaluated variant within the genome to date. Combining our knowledge from these studies with our rapidly accumulating understanding of structural variants, it is apparent that the extent of genetic dissimilarity between any 2 individuals is considerable and much greater than that which was previously recognized. Clearly, this more diverse view of the genome has significant implications for allogeneic hematopoietic stem cell transplantation, not least in the generation of transplant antigens but also in terms of individual susceptibility to transplant-related toxicities. With advances in DNA sequencing technology we now have the capacity to perform genome-wide analysis in a high throughput fashion, permitting a detailed genetic analysis of patient and donor prior to transplantation. Understanding the significance of this additional genetic information and applying it in a clinically meaningful way will be one of the challenges faced by transplant clinicians in the future.

Mirasol PRT treatment of donor white blood cells prevents the development of xenogeneic graft-versus-host disease in Rag2?/??c?/?double knockout mice

BACKGROUND

Mirasol PRT (Navigant Biotechnologies) treatment utilizes exposure to light in the presence of riboflavin to introduce irreparable lesions to nucleic acids thereby inhibiting pathogen and WBC replication. The ability of Mirasol PRT-treated mononuclear cells (MNCs) to generate xenogeneic graft-versus-host disease (GVHD) responses was used to model transfusion-associated GVHD (TAGVHD).

STUDY DESIGN AND METHODS

Pairs of human MNCs from five different individual donors that had or had not received Mirasol PRT treatment and contained 30 x 10(6) CD3+ cells were injected intraperitoneally into sublethally irradiated (350 cGy) Rag2(-/-)gamma c(-/-) double-knockout mice. Recipient mice were weighed and observed regularly and euthanized when they exhibited symptoms of GVHD or at termination of the experiment. Recipient lymphoid compartments were collected and phenotyped for the presence of human lymphoid cells. The presence of human cytokines and/or immunoglobulins in the recipient plasma was also used to detect the presence of human cells.

RESULTS

Twelve of 14 mice injected with untreated cells developed xenogeneic GVHD, whereas 0 of 14 mice injected with Mirasol PRT-treated cells developed xenogeneic GVHD. End-stage xenogeneic GVHD in the recipients of untreated cells was characterized by the presence of splenic human cytolytic CD4+ and CD8+ cells, with high levels of interferon-gamma, interleukin-10, and xenoreactive antibodies in the plasma.

CONCLUSION

Mirasol PRT treatment of the donor MNCs abolished xenogeneic GVHD responses, indicating that the use of Mirasol PRT treatment of blood products should prevent the development of TAGVHD.

Decreased expression of eukaryotic initiation factor 3f deregulates translation and apoptosis in tumor cells

The eukaryotic initiation factor 3f (eIF3f) is the p47 subunit of the multi-subunit eIF3 complex. eIF3 plays an important role in translation initiation. In the present study, we investigate the biological function of eIF3f in translation and apoptosis in tumor cells. We demonstrated for the first time that eIF3f is downregulated in most human tumors using a cancer profiling array and confirmed by real-time reverse transcription PCR in melanoma and pancreatic cancer. Overexpression of eIF3f inhibits cell proliferation and induces apoptosis in melanoma and pancreatic cancer cells. Silencing of eIF3f protects melanoma cells from apoptosis. We further investigated the biological function of eIF3f. In vitro translation studies indicate that eIF3f is a negative regulator of translation and that the region between amino acids 170 and 248 of eIF3f is required for its translation regulatory function. Ectopic expression of eIF3f inhibits translation and overall cellular protein synthesis. Ribosome profile and ribosomal RNA (rRNA) fragmentation assays revealed that eIF3f reduces ribosomes, which may be associated with rRNA degradation. We propose that eIF3f may play a role in ribosome degradation during apoptosis. These data provide critical insights into the cellular function of eIF3f and in linking translation initiation and apoptosis.

Genetics of Risk Factors for Graft-Versus-Host Disease

Modern understanding of the genetic basis of graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (HSCT) involves knowledge of human leukocyte antigen (HLA), killer immunoglobulin-like receptors (KIR), cytokine genes, and their interactions. Insights into the immunogenetic basis of GVHD come from long-standing clinical experience in the use of myeloablative conditioning regimens and donor bone marrow as the grafting source. Under these circumstances, donor T-cell recognition of host HLA can cause GVHD. The recent elucidation of HLA class I as ligands for natural killer (NK) cell inhibitory KIR demonstrates that GVHD is the result of a complex interplay between the innate and adaptive immune responses. The extent to which T cells and NK cells contribute to clinical GVHD is a function of the host post-conditioning environment, immunosuppressive treatments, and the content of the graft source. The contribution of donor and host genetic differences in cytokine genes in modulating risks of GVHD has recently been recognized.

The cyclin-dependent kinase 11 interacts with NOT2

The caspase-processed cyclin-dependent kinase 11 (formerly known as PITSLRE) is implicated in apoptotic signaling. However, the mechanism of apoptotic signal transduction through CDK11(p46) is still unclear. We used a yeast two-hybrid screening strategy and identified NOT2 as an interacting partner of caspase-processed C-terminal kinase domain of CDK11 (CDK11(p46)). We demonstrate that CDK11(p46) directly interacts with NOT2 in vitro and in human cells. The NOT domain in the C-terminal part of NOT2 is responsible for the association between CDK11(p46) and NOT2. Both NOT2 and CDK11(p46) predominantly co-localized in the nucleus. Furthermore, we show that overexpression of NOT2 reduces luciferase mRNA and induces apoptosis. However, NOT2 is not phosphorylated by CDK11(p46). These findings suggest that CDK11 may contribute to apoptosis by regulating the activity of NOT2 independent of its kinase activity.

The effects of interleukin 10 and interferon gamma cytokine gene polymorphisms on survival after autologous bone marrow transplantation for patients with breast cancer

Several clinical trials evaluating the induction of autoimmune graft-versus-host disease (GVHD) after autologous bone marrow transplantation (BMT) as antitumor immunotherapy have shown that autologous GVHD is associated with increased production of interleukin (IL)-10. The induction of autologous GVHD also segregated with single nucleotide polymorphisms in the IL-10 promoter region (IL-10 -592 and IL-10 -1082 ) and with CA repeats in the first intron of the interferon (IFN)-gamma gene. Polymorphisms within these promoter regions can significantly modify the cytokine response because of differential transcription factor efficiency. This study evaluated the relationship between inheritance of polymorphisms within the IL-10 promoter and in the IFN-gamma gene and the overall survival of patients who received autologous BMT for metastatic breast cancer. Peripheral mononuclear cells from 87 women enrolled in 3 autologous BMT (plus induction of autologous GVHD) clinical trials were examined. By using a Cox proportional hazard model, trends in survival after autologous BMT were analyzed. The model included inheritance polymorphisms of IL-10 -592 , IL-10 -1082 , CA repeats within the first intron of the IFN-gamma gene, estrogen and progesterone receptor status, and stage of disease. Increased survival was significantly associated with patients having the IL-10 -592 promoter allele associated with high IL-10 production (hazard ratio, 0.23; 95% confidence interval, 0.09-0.55; P = .001). The effect of the strong IL-10 promoter allele on survival seems to be independent of the development of clinical autologous GVHD. However, decreased survival was significantly associated with patients having CA repeats associated with higher IFN-gamma transcription (hazard ratio, 2.34; 95% confidence interval, 1.21-4.54; P = .011). Inheritance of specific alleles that modify IL-10 and IFN-gamma production may have unexpected effects on the efficacy of immune-based strategies after autologous BMT. Additional studies are necessary to further define the influence of IL-10 and IFN-gamma on the immune response after BMT.

Genetic variation in the IL-10 pathway modulates severity of acute graft-versus-host disease following hematopoietic cell transplantation: synergism between IL-10 genotype of patient and IL-10 receptor beta genotype of donor

We have previously shown that the interleukin 10 (IL-10)/-592*A allele of the recipient is associated with less severe acute graft-versus-host disease (GVHD) and a lower risk of nonrelapse mortality after hematopoietic cell transplantation (HCT) from an HLA-identical sibling. In the present study, we examined variation in the IL-10 receptor beta gene as a further test of the hypothesis that the IL-10 pathway regulates the risk of acute GVHD. A single nucleotide polymorphism (A/G) at cDNA position 238 of the IL-10 receptor beta gene (IL10RB/c238) was genotyped in 953 HC transplant recipients and their HLA-identical sibling donors. IL-10/-592 and IL10RB/c238 genotypes were tested for association with GVHD by multivariable analysis. The IL-10/-592*A allele of the recipient and IL10RB/c238*G allele of the donor were significantly associated with a lower risk of grades III-IV acute GVHD (trend P < .001 and P = .02, respectively). The donor IL10RB/c238*G allele provided protection among patients with the IL-10/-592 A/C or A/A genotypes but not among patients with the high-risk IL-10/-592 C/C genotype. These data suggest an interaction of the patient IL-10/-592 and donor IL10RB/c238 genotypes on risk of GVHD, further supporting the hypothesis that the IL-10 pathway plays an important role in controlling the severity of acute GVHD.

CCR6 regulates CD4+ T-cell-mediated acute graft-versus-host disease responses

We studied the role of chemokine receptor CCR6 in acute graft-versus-host disease (GvHD), a pathology in which activated, host antigen-specific donor T cells selectively damage tissues such as skin, liver, and gut. GvHD incidence was reduced in major histocompatibility complex (MHC) class II-mismatched recipients of CD4+ T cells from CCR6-deficient donors. In MHC-matched/minor histocompatibility antigen-mismatched recipients of CD4+CD45RB(high) T cells from CCR6-deficient donors, infiltration of CD45+ and CD4+ cells to skin and gut, as well as lesion onset, were significantly delayed, and pathologic symptoms were milder. Consistent with this, in skin and gut of recipients of naive T cells from CCR6-deficient donors we observed lower levels of interferon gamma (IFN-gamma), interleukin 10 (IL-10), and the chemokines that control activated T-cell homing. We suggest a role for CCR6 in recruiting alloreactive CD4+ T cells to target tissues and identify CCR6 as a potential therapeutic target for GvHD.

Functionally divergent T lymphocyte responses induced by modification of a self-peptide from a tumor-associated antigen

The N- and C-terminal flanking domains of the invariant chain peptide, CLIP, have remarkable immunological properties. Addition of these flanking domains to a foreign peptide antigen increases its immunologic potency. The present studies evaluated whether altering a peptide ligand from the tumor-associated antigen c-neu with the flanking domains of CLIP could modify the systemic immune response. The results indicate that the immunogenicity of an MHC class II restricted peptide (NEU) derived from c-neu was significantly altered by addition of the flanking domains from CLIP. Interestingly, selective modification of the peptide with either the N- or the C-terminal flanking domains resulted in functionally divergent systemic immune responses. Immunization of normal F344 rats with the NEU peptide modified with the N-terminal domain of CLIP (N-NEU) resulted in an immune response primarily consisting of type 1 (IL-2, IFNgamma) cytokine producing T cells. On the other hand, type 2 (IL-4) cytokine responses were largely predominant following immunization with the self-peptide modified with the C-terminal flanking domain (NEU-C). The functionally divergent responses elicited by the modified self-peptides were accompanied by significant changes in the expression of the CD28/CTLA4/B7 family of co-stimulatory molecules. Immunization with the N-NEU peptide led to enhanced expression of CD28 in the antigen-specific, CD4+ T cell compartment while expression of B7.1 was dramatically reduced in antigen-specific CD8+ T cells. Comparatively, expression of CTLA4 was down-regulated in the antigen-specific CD4+ T cell compartment following immunization with NEU-C peptide. The N-NEU peptide also had a direct effect on dendritic cells leading to the up-regulation of B7.1 expression. Taken together, functionally divergent systemic immune responses can be elicited by strategically altering a self-peptide ligand with the N- and C-terminal flanking domains of CLIP. Moreover, changes in expression of co-stimulatory molecules that are required for T cell activation and T cell-T cell communication may account for the polarization of the immune response elicited by the chimeric peptides.

Cytokine Gene Polymorphisms in Patch‐stage Mycosis Fungoides

Cytokine production is under genetic control and certain allelic variants of cytokine genes are associated with lower or higher cytokine production in vitro and in vivo. The general concept is that a shift from a Th1 to a Th2 cytokine profile accompanies disease progression from patch-stage mycosis fungoides to tumour stage, although the results of the studies carried out have not been entirely conclusive. We aimed to investigate whether certain cytokine polymorphisms might represent a risk factor for developing patch-stage mycosis fungoides. Genotyping for IFN-gamma (Th1 cytokine), IL-6, IL-10 (Th2 cytokines), TNF-alpha and TGF-beta 1 was undertaken for 33 patients with patch-stage mycosis fungoides and the results were compared with those in a control group. Genotype distribution showed no significant differences between the patients and the controls for any of the five cytokines studied. Our study suggests that patch-stage mycosis fungoides is not determined by a specific genotype polymorphism. However, further studies on larger numbers of cases are needed before definite conclusions can be drawn.

Antigen-specific T-lymphocyte responses in acute and chronic syngeneic graft-versus-host disease

Administration of cyclosporine (CyA) following autologous bone marrow transplantation elicits a T-lymphocyte autoaggression syndrome with remarkable similarity to acute and chronic graft-versus-host disease (GVHD). This syndrome termed syngeneic (S) GVHD is mediated by a restricted repertoire of autoreactive T cells that promiscuously recognize major histocompatibility complex (MHC) class II determinants in association with a peptide from the invariant chain (CLIP). The present studies evaluated and compared antigen-specific autoreactive T cells during acute and chronic SGVHD isolated ex vivo with a soluble MHC class II-immunoglobulin (sMHC class II-Ig) molecular construct. Two major subsets were detected that had overlapping specificity recognizing the MHC class II binding domain of CLIP but were differentially dependent on the N- and C-terminal flanking domains of this peptide. Both subsets were detected in acute and chronic SGVHD. Interestingly, the cytokine profiles of the CLIP-reactive T cells closely correlated with the onset and progression of disease. Levels of type 1 cytokines, particularly IFN-gamma mRNA production assessed by quantitative polymerase chain reaction (PCR), were dominant during acute SGVHD, whereas chronic SGVHD was associated with type 2 cytokine mRNA production. Although there was a dramatic polarization with respect to cytokine production, only subtle changes in antigen specificity were detected. Of additional interest, autoreactive T cells producing IL-10 mRNA were detected in both acute and chronic SGVHD, suggesting that this cytokine may play an important but perhaps paradoxical role in both the onset and progression of this experimental autoaggression syndrome.

The safety of interferon-?-1b therapy for invasive fungal infections after hematopoietic stem cell transplantation

BACKGROUND

The restoration of normal immune responses, especially of the T-helper type 1 immune response, is an important predictor of fungal infection outcome in patients with malignant disease who undergo hematopoietic stem cell transplantation (HSCT). The authors sought to evaluate the safety of adjuvant recombinant interferon-gamma-1b as an immune-modulatory therapy HSCT recipients.

METHODS

Thirty-two patients received interferon-gamma-1b after undergoing HSCT at the author's institution between 1998 and 2003. A retrospective analysis was undertaken after obtaining permission from the Institutional Review Board.

RESULTS

Twenty-six of 32 patients (81%) received allogeneic stem cell grafts. All but 1 patient received interferon-gamma-1b and antifungals to treat infections; the other patients received interferon-gamma-1b to promote autologous graft-versus-tumor effect. Interferon-gamma-1b usually was administered at a dose of 50 mug subcutaneously every other day. The median duration (+/- standard deviation) of interferon-gamma-1b therapy was 6+/-6.5 doses (range, 1-29 doses), and the median cumulative dose was 487+/-453 mug (range, 35-2175 microg). During therapy with interferon-gamma-1b, fever was common (n=9 patients; 28%). In 1 patient (3%), new-onset lymphocytopenia occurred but resolved after cytokine therapy was discontinued; there were no interferon- gamma-1b-related episodes of neutropenia, thrombocytopenia, anemia, or liver dysfunction. Interferon-gamma-1b therapy did not precipitate or exacerbate acute or chronic graft-versus-host disease (GVHD). In fact, in 2 of 7 patients (29%) with acute GVHD and in 3 of 10 patients (30%) with chronic GVHD, significant improvements in GVHD were noted during therapy with interferon-gamma-1b. Among the 26 patients with aspergillosis, 14 patients (54%) died. However, 5 of 10 patients (50%) with presumed pulmonary aspergillosis, 3 of 9 patients (33%) with probable pulmonary aspergillosis, 1 of 2 patients (50%) with definite pulmonary aspergillosis, and 3 of 5 patients (60%) with disseminated aspergillosis responded to antifungals and adjuvant interferon-gamma-1b.

CONCLUSIONS

Recombinant interferon-gamma-1b was tolerated without serious adverse reactions in HSCT recipients. A large, prospective, randomized study will be needed to evaluate the efficacy of this cytokine in high-risk HSCT recipients who have invasive mycoses.

Cytolytic effector mechanisms and gene expression in autologous graft-versus-host disease: distinct roles of perforin and Fas ligand

The administration of cyclosporin A (CsA) after autologous stem cell transplantation (SCT) paradoxically elicits a systemic autoimmune syndrome that resembles graft-versus-host disease (GVHD); this is termed autologous GVHD (autoGVHD). Although dominated by activated CD8+ cytotoxic T lymphocytes, the complex cellular reaction also includes CD4+ T cells and involves multiple effector mechanisms. To determine the temporal development and relative importance of these mechanisms in autoGVHD, perforin/granzyme, Fas ligand (FasL), interferon-gamma (IFN-gamma), tumor necrosis factor (TNF)-alpha, and interleukin-18 gene expression in peripheral blood mononuclear cells was examined in 36 patients treated with CsA after SCT. Quantitative real-time polymerase chain reaction analysis revealed that perforin/granzyme B, TNF-alpha, and interleukin-18 messenger RNA (mRNA) levels in peripheral blood mononuclear cells from patients in whom autoGVHD developed were markedly higher (and temporally associated with the onset of autoaggression) compared with the levels detected in healthy individuals and in control, non-CsA-treated SCT patients. It is interesting to note that patients in whom autoGVHD did not develop also demonstrated increased mRNA levels for these cytokines: however, expression was substantially lower compared with that in patients with autoGVHD. It is important to note that IFN-gamma mRNA levels were selectively increased in CD8+ cells only from patients in whom autoGVHD developed. The development of autocytolytic T cells in autoGVHD correlated with increased expression of perforin, IFN-gamma, and TNF-alpha mRNA. Furthermore, enhanced autoreactive T-cell activity and the induction of autoGVHD was also concordant with perforin and TNF-alpha mRNA upregulation in CD4+ cells. Surprisingly, FasL mRNA levels were significantly decreased, with a progressive loss of FasL mRNA expression as autocytolytic activity increased. These findings suggest that IFN-gamma/perforin-based CD8+ cytotoxic T lymphocytes seem to play a dominant role in autoGVHD and that TNF-alpha/perforin-based CD4+ cells may amplify this autoaggressive syndrome. The FasL pathway may play an important role in the regulation of this immune syndrome.

Functional divergence of antigen-specific T-lymphocyte responses in syngeneic graft-versus-host disease

Administration of cyclosporine after autologous bone marrow transplantation elicits a T-lymphocyte autoaggression syndrome with remarkable similarity to graft-versus-host disease (GVHD). This syndrome, termed syngeneic GVHD (SGVHD), with both acute and chronic phases, is mediated by a restricted repertoire of autoreactive T cells that promiscuously recognize major histocompatibility complex (MHC) class II determinants in association with a peptide from the invariant chain (MHC class II-invariant chain peptide; CLIP). This study evaluated and compared antigen-specific autoreactive T cells during acute and chronic SGVHD ex vivo isolated with a soluble MHC class II immunoglobulin molecular construct. This approach allows for the direct assessment of the functional behavior of the effector T cells without potential modification by in vitro culture. Two major subsets were detected that had overlapping specificity recognizing the MHC class II-binding domain of CLIP but that were differentially dependent on the N- and C-terminal flanking domains of this peptide. The N- and C-terminal subsets were primarily associated with acute and chronic SGVHD, respectively. The cytokine profiles of the CLIP-reactive T cells, however, were most informative and closely correlated with the onset and progression of disease. Levels of type 1 cytokine, particularly interferon-gamma, messenger RNA (mRNA) production, assessed by quantitative polymerase chain reaction, were dominant during acute SGVHD, whereas chronic SGVHD was associated with type 2 cytokine mRNA production. Although there was a dramatic polarization with respect to cytokine production, only subtle changes in antigen specificity could be detected. Unexpectedly, the functional behavior within the antigen-specific effector cell populations is not fixed and seems to change as the disease progresses to the chronic phase. Concordant with the evolution of the effector T-cell response is a differential loss in B7.1 mRNA expression in the N-terminal CLIP-reactive T-cell subset that may reflect the regulation of this autoimmune response. Of additional interest, autoreactive T cells producing interleukin-10 mRNA were detected in both acute and chronic SGVHD, suggesting that this cytokine may play an important but perhaps paradoxical role in both the onset and progression of this experimental autoaggression syndrome.

Association of Foxp3 regulatory gene expression with graft-versus-host disease

Graft-versus-host disease (GVHD) is characterized by an impairment of mechanisms that underlie the development of immunologic tolerance. Although the cytokine storm associated with GVHD leads to expression of cell surface markers on both effector and regulatory T cells, regulatory CD4+ T cells that play an instrumental role in the maintenance of tolerance appear to uniquely express the Foxp3 transcriptional repressor. Foxp3 mRNA expression was significantly decreased in peripheral blood mononuclear cells from patients with either allogeneic GVHD or autologous GVHD compared with patients without GVHD. Expression of Foxp3 negatively correlated with the severity of GVHD but positively correlated with recent thymic emigrants. The results suggest that defective thymic function contributes to the impaired reconstitution of immune regulatory mechanisms following transplantation. The decrease in regulatory mechanisms after transplantation appears to provide an environment permissive to the development of GVHD.

Autologous peripheral blood stem cell transplantation with induction of autologous graft-versus-host disease in acute myeloid leukemia

We studied whether the induction of autologous graft-versus-host disease (GVHD) has an antileukemic effect and consequently increases the survival of patients undergoing autologous peripheral blood stem cell transplantation (PBSCT). In all, 22 acute myeloid leukemia patients with favorable and intermediate cytogenetic risk, in their first complete remission, were administered cyclosporine c.i.v. from day 0 to day +28 at a dose of 3.0 mg/kg per day and interferon-gamma (IFN-gamma) at 0.025 mg/m(2) s.c. every other day from day +14 to day +42 following autologous PBSCT. Natural-killer (NK)-cell activity assays and skin biopsies were performed. Successful engraftment was achieved in all patients at a median of 13 days without significant additional toxicity. Histologically confirmed cutaneous GVHD developed in 12 patients, and NK-cell activity was significantly augmented after autologous PBSCT in those patients (P=0.03). After a median follow-up duration of 37.7 months (range, 7.3-72.8), the 3-year disease-free survival (DFS) and overall survival (OS) rates were 64.4 and 73.1%, respectively, without significant correlation with GVHD status or augmentation of NK-cell activity. These data suggest that the administration of cyclosporine and IFN-gamma following autologous PBSCT improves OS and DFS, which may be attributable to the antileukemic effect, although no difference in survival could be demonstrated between cutaneous GVHD-positive and -negative groups.

Enhancement of cyclosporin A-induced autologous graft-versus-host disease after peripheral blood stem cell transplantation by utilizing selected CD34+ cells

Although autologous graft-versus-host disease (GVHD) can be induced by administration of cyclosporin A (CsA) after peripheral blood stem cell transplantation (PBSCT), the incidence appears to be remarkably lower compared to the incidence after bone marrow transplantation. The reduced incidence of autologous GVHD after PBSCT may be attributed to peripheral regulatory cells that are transferred with the stem cell inoculum. To determine whether transplantation of CD34-selected peripheral blood stem cells (PBSCs) leads to potentiation of autologous GVHD, five patients with malignant lymphoma were transplanted with CD34-selected PBSCs, followed by administration of CsA and interferon (IFN)-gamma. Inducibility of autologous GVHD and autocytotoxic activities of peripheral blood mononuclear cells (PBMCs) after transplantation were assessed. All patients demonstrated prompt hematologic recovery. Cytotoxic activity of PBMCs against autologous lymphocytes was detectable in four of four patients analyzed during a limited period from days 14 to 34 post-transplant. An erythematous rash compatible with GVHD, confirmed by skin biopsy, developed in three of five patients. One of the three patients developed not only skin, but also gut and liver GVHD. Transplantation of the CD34-selected stem cell graft that does not accompany transfusion of regulatory cells may potentiate the inducibility of autologous GVHD by the administration of CsA and IFN-gamma.

Pneumococcal septic shock is associated with the interleukin-10-1082 gene promoter polymorphism

Polymorphisms in the tumor necrosis factor and interleukin-10 genes, linked to cytokine inducibility, may influence the inflammatory response to infection. We studied the biallelic interleukin-10-1082 promoter, the tumor necrosis factor-alpha-308 promoter, and the lymphotoxin-alpha polymorphisms with regard to the development of septic shock in pneumococcal infection. Sixty-nine patients with pneumococcal disease (61 patients with community-acquired pneumonia, 5 patients with meningitis, and 3 patients with pneumonia and meningitis) and 50 age-matched control subjects were included. The polymorphisms were determined by the polymerase chain reaction. In patients with pneumococcal disease, the lipopolysaccharide-stimulated tumor necrosis factor and interleukin-10 release from whole blood were measured by ELISA. Sepsis severity was documented according to standard criteria. No significant genotypic differences were seen between patients and control subjects. Thirteen of 69 patients with pneumococcal disease developed septic shock. Interleukin-10 allele G homozygous patients had the highest risk for septic shock (odds ratio of 6.1; 95% confidence interval, 1.4-27.2; corrected p = 0.024). The stimulated interleukin-10 release was highest in interleukin-10 G homozygous patients (p = 0.04). In conclusion, interleukin-10 polymorphism, associated with high interleukin-10 inducibility, might influence the outcome of pneumococcal infection via induced immunosuppression and impaired bacterial clearance.

Unexpected T-cell diversity in syngeneic graft-versus-host disease revealed by interaction with peptide-loaded soluble MHC class II molecules

BACKGROUND

Administration of cyclosporine after syngeneic bone marrow transplantation elicits a systemic autoaggression syndrome termed syngeneic graft-versus-host disease (SGVHD). The effector T cells recognize a peptide from the invariant chain termed CLIP (MHC class II invariant chain peptide) presented on MHC class II molecules. Moreover, the N-terminal flanking region of CLIP interacts with the T-cell receptor (TcR) beta chain.

METHODS

The current study uses a novel approach to isolate and examine the responding T cells ex vivo. A soluble MHC class II molecule using immunoglobulin (Ig)G (MHC class II-Ig) as a scaffold was constructed. The MHC class II-Ig molecule loaded with different peptide variants of CLIP (lacking the N-terminal or C-terminal flanking regions of CLIP) was used to isolate antigen-specific T cells from animals with SGVHD by panning or by flow cytometric sorting.

RESULTS

Two subsets of antigen specific T cells restricted by the N- and C-terminal flanking regions of CLIP can be isolated during acute SGVHD that express the Vbeta8.5 TcR determinant but secrete different cytokines (interferon [IFN]-gamma, interleukin [IL]-10) as detected by real-time quantitative polymerase chain reaction (PCR). Spectratyping of the complementarity-determining region 3 regions reveals that the N-terminal CLIP reactive population has greater diversity in both the CDR3 and J regions than the C-terminal CLIP reactive subset. Interestingly, the N-terminal CLIP reactive cells can be preferentially detected in the target tissues during acute SGVHD. However, only IFN-gamma messenger (m)RNA was detected in the tissues.

CONCLUSION

The ability to isolate and examine antigen specific T cells ex vivo has revealed unexpected differences in TcR diversity and cytokine production in SGVHD.

The p34cdc2-related cyclin-dependent kinase 11 interacts with the p47 subunit of eukaryotic initiation factor 3 during apoptosis

Cyclin-dependent kinase 11 (CDK11; also named PITSLRE) is part of the large family of p34(cdc2)-related kinases whose functions appear to be linked with cell cycle progression, tumorigenesis, and apoptotic signaling. However, substrates of CDK11 during apoptosis have not been identified. We used a yeast two-hybrid screening strategy and identified eukaryotic initiation factor 3 p47 protein (eIF3 p47) as an interacting partner of caspase-processed C-terminal kinase domain of CDK11 (CDK11(p46)). We demonstrate that the eIF3 p47 can interact with CDK11 in vitro and in vivo, and the interaction can be strengthened by stimulation of apoptosis. EIF3 p47 contains a Mov34/JAB domain and appears to interact with CDK11(p46) through this motif. We show in vitro that the caspase-processed CDK11(p46) can phosphorylate eIF3 p47 at a specific serine residue (Ser(46)) and that eIF3 p47 is phosphorylated in vivo during apoptosis. Purified recombinant CDK11(p46) inhibited translation of a reporter gene in vitro in a dose-dependent manner. In contrast, a kinase-defective mutant CDK11(p46M) did not inhibit translation of the reporter gene. Stable expression of CDK11(p46) in vivo inhibited the synthesis of a transfected luciferase reporter protein and overall cellular protein synthesis. These data provide insight into the cellular function of CDK11 during apoptosis.