Study protocol: the OptiScreen-Study: optimized psycho-oncological care-from screening to intervention.

PURPOSE: Adequate, needs-oriented psycho-oncological care contributes to reducing psychological distress in cancer patients and their relatives and improving quality of life. Regarding the precise determination of objective and subjective needs, there are often discrepancies in practice between the screening instrument completed by patients, the clinical impression of the treatment team, and the judgment of the psycho-oncology team. METHODS: The present multicenter study "OptiScreen", involving three German Comprehensive Cancer Centers (Hannover, Leipzig, Dresden), aims to professionalize psychosocial screening to enable targeted and needs-based allocation to psycho-oncological support. Optimization and professionalization of the screening process will be achieved by training of oncological nursing staff to improve the targeted identification of distressed patients and provide them with needs-based psycho-oncological care. The non-randomized pre-post study will include inpatients with gastrointestinal cancers from the visceral oncology centers at the three sites. First, the comparison group (CG) will be assessed of N = 300. After completion of nursing training, the intervention group (IG) with N = 600 patients will be evaluated by validated questionnaires. RESULTS: The aim is to reduce barriers on both the patient and treatment side by promoting interdisciplinary dialogue and linking the screening with a personal consultation offer provided by the nurses, which should help to increase utilization and reduce patients' fears, shame and information deficits. CONCLUSION: It is not sufficient to establish a well-validated screening procedure, it also has to be feasible and useful in clinical practice. "OptiScreen" aims to improve the psycho-oncological care situation. In parallel, the study enables the professionalization of psycho-oncological care with the involvement of important professional groups (e.g. nursing) and thus aims to develop a "best practice model".

Psychological Distress in a Sample of Inpatients With Mixed Cancer-A Cross-Sectional Study of Routine Clinical Data.

BACKGROUND: The diagnosis and treatment of cancer are associated with psychological distress that often leads to a significant reduction in emotional and physical well-being and quality of life. Early detection of psychological distress is therefore important. This study aims to assess the psychological distress of inpatient cancer patients using routine clinical data. Furthermore, variables and problems most strongly associated with psychological distress should be identified. MATERIALS AND METHODS: N = 1,869 inpatients were investigated (mean age = 60.89 years; 35.94% female) using the National Comprehensive Cancer Network Distress Thermometer and problem checklist to assess distress as well as multiple possible problem areas. Visceral oncological cancer (31.6%) was the most common tumor diagnosis, followed by skin cancer (26.2%) and urological cancer (21.7%). RESULTS: 65.9% of the sample experienced high levels of distress (Distress Thermometer ≥ 5). Female sex, stage 4 of disease, and visceral and head and neck cancer emerged as risk factors for high distress. A younger age (<65 years) was significantly correlated with higher distress. The most frequently self-reported problems were fears (50.1%), worry (49.9%), and fatigue (49.1%). Patients with all 3 of these problems had 24 times higher risk [odds ratio (OR) = 23.9] for high levels of distress than patients without these problems. Women reported significantly more practical, emotional, and physical problems than men. Younger (<50 years) and middle-aged patients (50-64 years) reported increased levels of practical, family, and emotional problems compared with older patients (≥65 years). DISCUSSION: Almost two-thirds of the sample reported high levels of distress. The most frequently reported problem areas were emotional and physical problems. These results can help to identify patients with high risk for psychological distress and, therefore, be used to optimize psychosocial and psycho-oncological care for patients with cancer.

Clinical-grade regulatory T cells: Comparative analysis of large-scale expansion conditions.

Recent clinical trials have indicated the high potential of regulatory T cells (Tregs) in the prevention of acute and chronic graft-versus-host disease (GvHD) after hematopoietic stem cell transplantation, but immune interventions require large numbers of Tregs. With respect to their limited natural occurrence, development and optimization of protocols for large-scale expansion of clinical-grade Tregs are essential if considered for therapeutic use. We compared different clinical-grade large-scale expansion protocols for repetitive transfer of large numbers of Tregs in clinical trials for the prevention of acute and/or chronic GvHD. Donor Tregs were isolated using magnetic-activated cell sorting (MACS) technology with good manufacturing practice-compliant devices. CD8 and CD19 depletion followed by CD25 enrichment resulted in the isolation of CD4+CD25+CD127- Tregs with a mean purity of 77%. Cell populations were expanded ex vivo using X-Vivo 15 (±rapamycin), TexMACS (±rapamycin), and CellGro DC (±rapamycin) in the presence of interleukin-2. The highest rates of expansion of clinical-grade Tregs were observed for X-Vivo 15 and CellGro DC without rapamycin in compared with all other expansion media tested. The suppressive capacity of the expanded Treg population was maintained under all conditions investigated. Our data suggest that expansion with CellGro provides data comparable to those obtained with TexMACS or X-Vivo 15 with rapamycin, although all three conditions did not provide the same propagation rate as X-Vivo 15 alone. With respect to functionality, phenotype, and stability, CellGro DC medium represents a reasonable alternative for good manufacturing practice-compatible large-scale ex vivo expansion.

Granzyme A Is Required for Regulatory T-Cell Mediated Prevention of Gastrointestinal Graft-versus-Host Disease.

In our previous work we could identify defects in human regulatory T cells (Tregs) likely favoring the development of graft-versus-host disease (GvHD) following allogeneic stem cell transplantation (SCT). Treg transcriptome analyses comparing GvHD and immune tolerant patients uncovered regulated gene transcripts highly relevant for Treg cell function. Moreover, granzyme A (GZMA) also showed a significant lower expression at the protein level in Tregs of GvHD patients. GZMA induces cytolysis in a perforin-dependent, FAS-FASL independent manner and represents a cell-contact dependent mechanism for Tregs to control immune responses. We therefore analyzed the functional role of GZMA in a murine standard model for GvHD. For this purpose, adoptively transferred CD4+CD25+ Tregs from gzmA-/- mice were analyzed in comparison to their wild type counterparts for their capability to prevent murine GvHD. GzmA-/- Tregs home efficiently to secondary lymphoid organs and do not show phenotypic alterations with respect to activation and migration properties to inflammatory sites. Whereas gzmA-/- Tregs are highly suppressive in vitro, Tregs require GZMA to rescue hosts from murine GvHD, especially regarding gastrointestinal target organ damage. We herewith identify GZMA as critical effector molecule of human Treg function for gastrointestinal immune response in an experimental GvHD model.

Primary EBV-positive Hodgkin's lymphoma of the CNS under azathioprine treatment: case report and review of the literature.

BACKGROUND: Retrospective and prospective cohort studies suggest that central nervous system involvement occurs in approximately 0.5% of patients with advanced Hodgkin's lymphoma. The isolated primary intracranial manifestation of Hodgkin's lymphoma is an extremely rare finding, with few cases reported in the literature. Little is known about the optimal treatment and prognosis of these tumors. Here, we present a case report with a review of the literature. CASE PRESENTATION: A 47-year-old Caucasian man with persistent frontal headache and unspecific vertigo for half a month was diagnosed with nodular space-occupying lesions in the cerebellum. His medical history included multiple sclerosis, which was treated for 20 years with the immunosuppressive drug azathioprine. Further staging revealed no additional lesions suspected of being malignant. The patient underwent total tumor resection. Immunohistopathological examination showed Epstein-Barr virus-associated classic Hodgkin's lymphoma. Diagnostic bone marrow punction excluded lymphoma involvement of the bone marrow. The patient had no B symptoms. Consequently, the patient was classified as having stage IEA disease according to the Modified Ann Arbor Classification of Hodgkin Lymphoma and received systemic chemotherapy followed by radiation therapy for the former cerebellar tumor region. He was in complete clinical remission at the last follow-up 9 months after the initial diagnosis. CONCLUSION: This case report and literature review suggest that multimodal treatment leads to a remarkable clinical outcome in Hodgkin's lymphoma with intracranial involvement.

Immunological aspects of Candida and Aspergillus systemic fungal infections.

Patients with allogeneic stem cell transplantation (SCT) have a high risk of invasive fungal infections (IFIs) even after neutrophil regeneration. Immunological aspects might play a very important role in the IFI development in these patients. Some data are available supporting the identification of high-risk patients with IFI for example patients receiving stem cells from TLR4 haplotype S4 positive donors. Key defense mechanisms against IFI include the activation of neutrophils, the phagocytosis of germinating conidia by dendritic cells, and the fight of the cells of the innate immunity such as monocytes and natural killer cells against germlings and hyphae. Furthermore, immunosuppressive drugs interact with immune effector cells influencing the specific fungal immune defense and antimycotic drugs might interact with immune response. Based on the current knowledge on immunological mechanism in Aspergillus fumigatus, the first approaches of an immunotherapy using human T cells are in development. This might be an option for the future of aspergillosis patients having a poor prognosis with conventional treatment.

Characterization of granulocyte colony stimulating factor for in vitro induction of regulatory T cells for cellular immune intervention in transplant medicine.

OBJECTIVES: The application of regulatory T cells in the field of solid-organ and hematopoietic stem cell transplantation is under investigation to develop novel cellular strategies for tolerance induction. Establishing in vitro procedures to induce and expand regulatory T cells seeks to overcome the limiting small number of this rare T cell population. The present study is based on growing evidence that granulocyte colony stimulating factor exerts immune regulatory function in the adaptive immune system and may induce regulatory T cells in vivo. MATERIALS AND METHODS: We analyzed the effect of recombinant granulocyte colony stimulating factor to directly convert CD4+CD25- T cells into regulatory T cells in vitro. Marker molecules were analyzed by quantitative reverse transcriptase-polymerase chain reaction and fluorescent-activated cell sorter analyses. Functional assays were performed to investigate the suppressive capacity of granulocyte colony stimulating factor stimulated T cells. RESULTS: Kinetic analyses of Foxp3 gene expression uncovered increased levels early after in vitro stimulation with granulocyte colony stimulating factor. However, protein analyses for the master transcription factor Foxp3 and other regulatory T cells revealed that granulocyte colony stimulating factor did not directly induce a regulatory T cell phenotype. Moreover, functional analyses demonstrated that granulocyte colony stimulating factor stimulation in vitro does not result in a suppressive, immune regulatory T cell population. CONCLUSIONS: Granulocyte colony stimulating factor does not induce regulatory T cells with a specific phenotype and suppressive potency in vitro. Therefore, granulocyte colony stimulating factor does not qualify for developing protocols aimed at higher regulatory T cell numbers for adoptive transfer strategies in solid organ and hematopoietic stem cell transplantation.

Reconstitution and phenotype of Tregs in CMV reactivating patients following allogeneic hematopoietic stem cell transplantation.

In experimental and clinical settings Tregs prevent graft-versus-host disease (GvHD) by inhibiting the proliferation and function of conventional T cells (Tconv). The suppressive potency of Tregs might also lead to the inhibition of protective antiviral T cell responses. As the control of CMV reactivation is important to improve the clinical outcome in allogeneic HSCT, we analyzed the Treg reconstitution in CMV reactivating patients with and without GvHD (n=47) in the first 6 months following transplantation. Most importantly, CMV reactivation does not correlate with the numerical reconstitution of CD4(+)CD25(high)CD127(-) Tregs. During CMV reactivation the proportion of Tregs within the CD4(+) T cell population decreased significantly independent of GvHD manifestation. A comprehensive FACS analysis was performed in order to characterize the phenotype of Tregs and Tconv cells in greater detail for activation, co-stimulation, proliferation, suppressive function and migratory capability. Interestingly, Tregs of patients with CMV reactivation showed a significantly higher CXCR3 expression. CD4(+) Tconv cells expressed significantly higher protein levels of the proliferation marker Ki67 correlating with a numerical increase of CD4(+) T cells. Our results indicate that Tregs are not inhibiting pathogen clearance by Tconv following HSCT, which is of high relevance for future Treg cell-based clinical trials in allogeneic HSCT.

Human regulatory T cells of G-CSF mobilized allogeneic stem cell donors qualify for clinical application.

Recent clinical studies demonstrate the high potency of regulatory T cells (Tregs) to control graft-versus-host disease in hematopoietic stem cell transplantation (SCT). However, the adoptive transfer of Tregs is limited by their low frequency in unstimulated donors and considerable concerns that G-CSF induced SC mobilization might have negative effects on the stability and function of Tregs. The isolation of Tregs from the G-CSF mobilized SC grafts would extend this novel strategy for tolerance induction to the unrelated setting and simplify global clinical application. We characterized CD4(+)CD25(high)CD127(-) Tregs from SC donors before and after G-CSF mobilization for their phenotype, function, and stability. After G-CSF application the Treg cell yield increased significantly. Donor Tregs retained their cytokine profile, phenotypic characteristics and in vitro expansion capacity after SC mobilization. Most importantly, in vivo G-CSF stimulated Tregs remained highly suppressive on the proliferation of effector T cells, also after in vitro expansion, and displayed a stable phenotype in epigenetic studies. The surface expression of CXCR3 is transiently reduced. However, donor-derived Tregs maintain their migratory properties after G-CSF stimulation. Therefore, the adoptive transfer of Tregs from G-CSF mobilized SC donors seems to be a feasible and safe strategy for clinical application in allogeneic SCT.

Biomarkers for acute and chronic graft-versus-host disease in regulatory T cells.

Despite improvements in the prevention and treatment of graft-versus-host disease (GvHD) this allogeneic immune response is still one of major complications following allogeneic stem cell transplantation (SCT). Identification of patients at risk for the development of acute and chronic GvHD would facilitate early intervention and thus improve overall survival. Diagnostic biomarkers identified in plasma are largely associated with T cell immune responses. Whereas donor effector T cells promote allogeneic immune responses, regulatory T cells (Tregs) may prevent GvHD by suppression of these alloreactive donor T cells. Therefore, we analyzed molecules associated with Tregs with respect to their potential predictive and prognostic impact on the development of acute and chronic GvHD. For this purpose, the Treg transcriptomes of patients with and without acute/chronic GvHD resulting from dynamical whole genome profiles of CD4(+)CD25(hi)CD127(lo/-) Tregs have been studied for potential GvHD biomarkers. We could identify potential biomarkers for acute/chronic GvHD like the activation marker phosphatidyl-5-kinase-gamma PIP5Kγ, FAS, CD44, CD69, and cell cycle regulators like cyclin A2, B1 and E2. Most importantly, the IKAROS transcription factor Eos, relevant for suppressive Treg function, might be relevant for the prediction of GvHD development. In addition markers like ANK3 (ankyrin), S100A8 and VCAN are indicative for acute GvHD, while IFIT3, IFI44 and IFIT1 are potential biomarkers for chronic GvHD. The identified markers have to be validated prospectively and might help to monitor and guide preventive immune intervention studies, especially adoptive donor Treg cell transfer.

Isolation strategies of regulatory T cells for clinical trials: phenotype, function, stability, and expansion capacity.

Recent clinical results demonstrate the highly effective potency of regulatory T cells (Tregs) to control graft-versus-host disease (GvHD). In this presented study, we directly compared different Treg subpopulations in order to define the most promising Treg target cell population for cellular intervention studies with respect to their phenotype, functional properties, stability, and expansion capacity. Different Treg cell populations have been isolated from healthy donors and characterized by fluorescence activated cell sorting (FACS) analysis for their phenotypic marker and purity, functional properties by suppression assay, stability by Treg-specific demethylated region (TSDR) of the Foxp3 promoter and their in vitro expansion capacity. The direct comparison of the respective Treg target cell populations identified CD4(+)CD25(hi)CD127(-) and CD4(+)CD25(hi)ICOS(+) Tregs as the most promising Treg population for fresh cell infusions in clinical trials with respect to cell yield, phenotype, function, and stability. The CD4(+)CD25(hi) Tregs qualified as the best candidate for in vitro expansion combining a highly stable phenotype with strong suppressive potential and attractive cell yield after repetitive stimulation. The suppressive capacity of freshly isolated CD4(+)CD25(hi)CD45RA(+) and CD49d(-)CD127(-) Tregs is comparable to freshly isolated CD4(+)CD25(hi), but inferior to CD4(+)CD25(hi)CD127(-) and CD4(+)CD25(hi)ICOS(+) Tregs. In vitro expansion of CD4(+)CD25(hi)CD45RA(+) and CD49d(-)CD127(-) Tregs resulted in cell populations with less suppressive potency compared with CD4(+)CD25(hi) expanded Tregs correlating well with a higher TSDR demethylation level. In conclusion, future clinical trials should favor CD4(+)CD25(hi)CD127(-) and CD4(+)CD25(hi)ICOS(+) Tregs for direct Treg cell transfer, whereas CD4(+)CD25(hi) Tregs qualify as best candidate for in vitro expansion.

Human regulatory T cells in allogeneic stem cell transplantation.

GVHD is still one of the major complications after allogeneic stem cell transplantation. Whereas murine data have clearly shown the beneficial effects of regulatory T cells (Tregs) on the prevention of GVHD, data from the human system are rare. Here, we present a comparative dynamic analysis of CD4(+)CD25(hi)CD127(lo/-) Tregs from patients with and without GVHD analyzing the whole genome profile over the first 6 months after stem cell transplantation, representing the most sensitive time window for tolerance induction. The Treg transcriptome showed a high stability. However, the comparison of Treg transcriptomes from patients with and without GVHD uncovered regulated gene transcripts highly relevant for Treg cell function. The confirmative protein analyses demonstrated a significantly higher expression of granzyme A, CXCR3, and CCR5 in Tregs of immune tolerant patients. These results point to a reduced suppressive function of Tregs from GVHD patients with diminished migration capacity to the target organs.

Acute but not chronic graft-versus-host disease is associated with a reduction of circulating CD4(+)CD25 (high)CD127 (low/-) regulatory T cells.

Defects in central and peripheral tolerance are thought to contribute to life-threatening graft-versus-host disease (GvHD), a severe complication following allogeneic stem cell transplantation (SCT). Recent investigations have demonstrated regulatory T cells (Tregs) to suppress allogeneic immune reactions. Therefore, SCT patients with no or critically low numbers of Tregs may have an increased risk of GvHD. To address this hypothesis, we analyzed the recovery of CD4(+)CD25(high)CD127(low/-) Tregs in the peripheral blood of patients who have never developed GvHD (n = 6), patients who developed acute/chronic GvHD (n = 18), and patients who developed chronic GvHD without an earlier acute manifestation (n = 5) every 30 days for the first 6 months after peripheral blood SCT (PBSCT). The number of Tregs continuously improved in acute/chronic GvHD patients, but always remained lower than Tregs quantified in patients who never developed a GvHD. In contrast, chronic GvHD patients who did not develop acute GvHD earlier displayed significantly increased Treg cell numbers at the timepoint of chronic inflammation. These results indicate that numerically deficient Tregs following PBSCT are associated with the development of acute but not chronic GvHD.

Pre T-cell receptor alpha (pTalpha) expression patterns and functional analysis in human T-cell lymphoblastic leukemia.

BACKGROUND: The pTalpha/preTCR regulates the beta-selection, a crucial T-cell developmental checkpoint, providing a most potent survival advantage to thymocytes mediated by the src-kinase p56(Lck). METHODS: To define the relevance of pTalpha in human T-cell lymphoblastic leukemia (T-ALL), we analyzed in T-ALL cell lines (n=14) pTalpha and p56(Lck) mRNA and protein expression as also the tyrosine-phosphorylation. The p56(Lck) specific src-protein-tyrosine kinase inhibitor (PTK-I) PP1 was used in growth inhibition assays. IC(50) value determination, cell cycle- and apoptosis analyses were performed in T-ALL-, non-T-ALL- and murine transgenic cell lines. RESULTS: pTalpha expression patterns were markedly different in T-ALL cell lines as compared to those reported for normal lymphoid counterparts. PP1 induced in 6/11 T-ALL cell lines a survival disadvantage resulting from a cell cycle arrest in the G(1/0) phase in thymic lymphoblastic cells and apoptosis induction in the immature cell line HSB-2, respectively. PP1 sensitive cell lines expressed the target protein p56(Lck) and showed a corresponding P-Tyr signal. CONCLUSION: Sensitivity of thymic T-ALLs to PP1 clearly underlines the impact of pTalpha mediated proliferation in this leukemic sub-type. In addition, p56(Lck) represents also independently of pTalpha a promising therapeutical target for the src-kinase inhibitors in neoplastic lymphoid diseases.

Regulatory T cells as therapeutic target in Hodgkin's lymphoma.

BACKGROUND: The clinical and pathological features of Hodgkin's lymphoma (HL) reflect an abnormal immune response that results from cytokines and chemokines secreted by Hodgkin/Reed-Sternberg (H/R-S) cells and/or the surrounding tissue. OBJECTIVE: Increasing evidence indicates that H/R-S cells recruit and/or induce regulatory T (Treg) cells that contribute to an ineffective immune clearance of the malignant cell types and may also impair effects of adaptive cellular immunotherapy applied in HL. METHODS: In this review we highlight advances in the understanding of immune regulation in HL, and discuss implications for immunotherapy in this disease by targeting Treg cells. However, the origin, development, migration and functional mechanism of these Treg cells are under discussion. RESULTS/CONCLUSION: As studies demonstrate that the depletion and/or manipulation of Treg cells enhance antitumor immunity, these novel treatment approaches may improve the therapy especially for patients with refractory or relapsed HL.

Radioimmunotherapy with [188Re]-labelled anti-CD66 antibody in the conditioning for allogeneic stem cell transplantation for high-risk acute myeloid leukemia.

Between July 2000 and June 2003 a total of 21 patients with high-risk acute myeloid leukemia (AML; n = 14), AML after myelodysplastic syndrome (MDS; n = 6) or advanced MDS (n = 1) were treated with an 188-Re labelled anti-CD66 antibody in the conditioning regimen for allogeneic stem cell transplantation. Radioimmunotherapy (RIT) was followed by standard full-dose conditioning with busulfan and high-dose cyclophosphamide in 11 patients and reduced intensity conditioning regimen in 10 patients. All patients received an unmanipulated allogeneic graft from alternative donors (n = 15) or a HLA-identical familiy donor (n = 6). With a median follow up of 42 months (23-60) disease free survival for all patients was 43%. Nine patients are still alive and in ongoing complete hematological remission. The treatment related mortality was 28.6% (n = 6) and an equal number of patients died of relapsing disease within 30-385 days after transplantation. Late organ toxicity, monitored for more than 1 year, was mild and not clinically relevant. The combination of RIT with chemotherapeutic conditioning seems to be a therapy with an acceptable risk of treatment related morbidity and mortality as well as occurrence of severe acute GvHD.

Identification of novel regulators in T-cell differentiation of aplastic anemia patients.

BACKGROUND: Aplastic anemia (AA) is a bone marrow failure syndrome mostly characterized by an immune-mediated destruction of marrow hematopoietic progenitor/stem cells. The resulting hypocellularity limits a detailed analysis of the cellular immune response. To overcome this technical problem we performed a microarray analysis of CD3+ T-cells derived from bone marrow aspirates and peripheral blood samples of newly diagnosed AA patients and healthy volunteers. Two AA patients were additionally analyzed after achieving a partial remission following immunosuppression. The regulation of selected candidate genes was confirmed by real-time RT-PCR. RESULTS: Among more than 22,200 transcripts, 583 genes were differentially expressed in the bone marrow of AA patients compared to healthy controls. Dysregulated genes are involved in T-cell mediated cytotoxicity, immune response of Th1 differentiated T-cells, and major regulators of immune function. In hematological remission the expression levels of several candidate genes tend to normalize, such as immune regulators and genes involved in proinflammatory immune response. CONCLUSION: Our study suggests a pivotal role of Th1/Tc1 differentiated T-cells in immune-mediated marrow destruction of AA patients. Most importantly, immune regulatory genes could be identified, which are likely involved in the recovery of hematopoiesis and may help to design new therapeutic strategies in bone marrow failure syndromes.

Classical Hodgkin's lymphoma: molecular evidence for specific alterations in circulating T lymphocytes.

OBJECTIVE: Impairment in cell-mediated immunity has long been recognized in classical Hodgkin's lymphoma (cHL). The immunosuppressive environment at the tumor site and/or a primary T-cell defect may contribute to an ineffective immune clearance of Hodgkin/Reed-Sternberg (H/R-S) cells. Here, we analyzed whether circulating T lymphocytes of cHL patients show specific alterations in gene expression with possible impact on anti-tumor immunity. MATERIAL AND METHODS: Gene expression profiles were performed from CD3+ T cells isolated from peripheral blood samples of untreated patients with cHL versus two control groups consisting of healthy donors and patients with sarcoidosis. The regulation of gene expression was confirmed in additional patients for selected genes by real-time RT-PCR. RESULTS AND CONCLUSION: Circulating T cells of cHL show a Th1 immune response likely supporting anti-tumor immunity. However, the molecular profile reveals an association between cell cycle transition/proliferation and induction of immune regulatory genes which may limit an effective anti-tumor immune response of differentiated Th1 cells.

Signatures of human regulatory T cells: an encounter with old friends and new players.

BACKGROUND: Naturally occurring CD4+ CD25+ regulatory T cells (TReg) are involved in the control of autoimmune diseases, transplantation tolerance, and anti-tumor immunity. Thus far, genomic studies on TReg cells were restricted to murine systems, and requirements for their development, maintenance, and mode of action in humans are poorly defined. RESULTS: To improve characterization of human TReg cells, we compiled a unique microarray consisting of 350 TReg cell associated genes (Human TReg Chip) based on whole genome transcription data from human and mouse TReg cells. TReg cell specific gene signatures were created from 11 individual healthy donors. Statistical analysis identified 62 genes differentially expressed in TReg cells, emphasizing some cross-species differences between mice and humans. Among them, several 'old friends' (including FOXP3, CTLA4, and CCR7) that are known to be involved in TReg cell function were recovered. Strikingly, the vast majority of genes identified had not previously been associated with human TReg cells (including LGALS3, TIAF1, and TRAF1). Most of these 'new players' however, have been described in the pathogenesis of autoimmunity. Real-time RT-PCR of selected genes validated our microarray results. Pathway analysis was applied to extract signaling modules underlying human TReg cell function. CONCLUSION: The comprehensive set of genes reported here provides a defined starting point to unravel the unique characteristics of human TReg cells. The Human TReg Chip constructed and validated here is available to the scientific community and is a useful tool with which to study the molecular mechanisms that orchestrate TReg cells under physiologic and diseased conditions.

The role of G-CSF in adaptive immunity.

Granulocyte colony-stimulating factor (G-CSF) is a pleiotropic cytokine playing a major role as regulator of hematopoiesis and innate immune responses. There is growing evidence that G-CSF also exerts profound immunoregulatory effects in adaptive immunity. G-CSF mediates anti-inflammatory reactions accompanied by TH2 cell differentiation and promotes tolerogeneic cell populations at both poles of APC/T cell interaction. These recent findings have highlighted the novel impact of G-CSF in transplantation tolerance and autoimmunity. G-CSF represents a powerful and promising cytokine to promote T cell tolerance in pathological conditions associated with a TH1/TH2 imbalance.