LAG3 and PD1 Regulate CD8+ T Cell in Diffuse Large B-cell Lymphoma Patients

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a clinically and genetically heterogeneous lymphoid malignancy. The unsatisfactory outcome for refractory patients has prompted efforts to explore new therapeutic approaches for DLBCL. However, the mechanisms involved in treatment associated with immune checkpoints remain unclear. This study is aimed at investigating the potential roles of programmed cell death protein 1 (PD1) and lymphocyte activation gene 3 (LAG3) in CD8+ T cells for treatment in DLBCL.

METHODS

Utilizing flow cytometry, we examined the content of T cells, the levels of cytokines, and the expression of PD1 and LAG3 in patients with DLBCL as well as in healthy controls. Levels of cytokines in CD8+ T cells from DLBCL patients before and after treatment were compared by blocking of PD1 and LAG3 in magnetic bead-sorted CD8+ T cells.

RESULTS

We found that the proportion of CD4+ T cells and CD8+ T cells was increased in DLBCL patients after treatment. The levels of cytokines trended toward those of healthy controls in treatment. PD1 (+), LAG3 (+), or PD1 (+) LAG3 (+) were all expressed in lower amounts in CD4+ T cells and CD8+ T cells after treatment than in untreated DLBCL patients. In addition, blockade of PD1 and LAG3 in sorted CD8+ T cells markedly inhibited cytokine production in response to treatment.

CONCLUSION

PD1 and LAG3 in CD8+ T cells may be important targets of therapy and play therapeutic role in patients with DLBCL.

Use of an anti-CD200-blocking antibody improves immune responses to AML in vitro and in vivo

Treatment of relapsed/resistant acute myeloid leukaemia (AML) remains a significant area of unmet patient need, the outlook for most patients remaining extremely poor. A promising approach is to augment the anti-tumour immune response in these patients; most cancers do not activate immune effector cells because they express immunosuppressive ligands. We have previously shown that CD200 (an immunosuppressive ligand) is overexpressed in AML and confers an inferior overall survival compared to CD200low/neg patients. Here we show that a fully human anti-CD200 antibody (TTI-CD200) can block the interaction of CD200 with its receptor and restore AML immune responses in vitro and in vivo.

Evodiamine inhibits vasculogenic mimicry in HCT116 cells by suppressing hypoxia-inducible factor 1-alpha-mediated angiogenesis

Evodiamine (Evo), a quinazoline alkaloid and one of the most typical polycyclic heterocycles, is mainly isolated from Evodia rugulosa. Vasculogenic mimicry (VM) is a newly identified way of angiogenesis during tumor neovascularization, which is prevalent in a variety of highly invasive tumors. The purpose of this study was to investigate the effect and mechanism of Evo on VM in human colorectal cancer (CRC) cells. The number of VM structures was calculated by the three-dimensional culture of human CRC cells. Wound-healing was used to detect the migration of HCT116 cells. Gene expression was detected by reverse transcription-quantitative PCR assay. CD31/PAS staining was used to identify VM. Western blotting and immunofluorescence were used to detect protein levels. The results showed that Evo inhibited the migration of HCT116 cells, as well as the formation of VM. Furthermore, Evo reduced the expression of hypoxia-inducible factor 1-alpha (HIF-1α), VE-cadherin, VEGF, MMP2, and MMP9. In a model of subcutaneous xenotransplantation, Evo also inhibited tumor growth and VM formation. Our study demonstrates that Evo could inhibit VM in CRC cells HCT116 and reduce the expression of HIF-1α, VE-cadherin, VEGF, MMP2, and MMP9.

Dissecting the Cellular Mechanism of Prostacyclin Analog Iloprost in Reversing Vascular Dysfunction in Scleroderma

OBJECTIVE

Intravenous iloprost improves Raynaud's phenomenon (RP) and promotes healing of digital ulcers in systemic sclerosis (SSc; scleroderma). Despite a short half-life, its clinical efficacy lasts weeks. Endothelial adherens junctions, which are formed by VE-cadherin clustering between endothelial cells (ECs), regulate endothelial properties including barrier function, endothelial-to-mesenchymal transition (EndoMT), and angiogenesis. We undertook this study to investigate the hypothesis that junctional disruption contributes to vascular dysfunction in SSc, and that the protective effect of iloprost is mediated by strengthening of those junctions.

METHODS

Dermal ECs from SSc patients and healthy controls were isolated. The effect of iloprost on ECs was examined using immunofluorescence, permeability assays, Matrigel tube formation, and quantitative polymerase chain reaction.

RESULTS

Adherens junctions in SSc were disrupted compared to normal ECs, as indicated by reduced levels of VE-cadherin and increased permeability in SSc ECs (P < 0.05). Iloprost increased VE-cadherin clustering at junctions and restored junctional levels of VE-cadherin in SSc ECs (mean ± SD 37.3 ± 4.3 fluorescence units) compared to normal ECs (mean ± SD 29.7 ± 3.4 fluorescence units; P < 0.05), after 2 hours of iloprost incubation. In addition, iloprost reduced permeability of monolayers, increased tubulogenesis, and blocked EndoMT in both normal and SSc ECs (n ≥ 3; P < 0.05). The effects in normal ECs were inhibited by a function-blocking antibody that prevents junctional clustering of VE-cadherin.

CONCLUSION

Our data suggest that the long-lasting effects of iloprost reflect its ability to stabilize adherens junctions, resulting in increased tubulogenesis and barrier function and reduced EndoMT. These findings provide a mechanistic basis for the use of iloprost in treating SSc patients with RP and digital ulcers.

Rikkunshito attenuates induction of epithelial-mesenchymal switch via activation of Sirtuin1 in ovarian cancer cells

Rikkunshito, a traditional Japanese herbal medicine, improves appetite via activation of gastrointestinal hormone ghrelin pathway. The function of ghrelin is mediated by growth hormone secretagogue receptor (GHSR1a), and ghrelin has been known to possess diverse physiological functions including growth suppression of some cancer cells. Considering that increased ghrelin signaling by Rikkunshito could enhance sirtuin1 (SIRT1) activity in nervous system, we aimed to investigate the effect of Rikkunshito in ovarian cancer cells. Ovarian cancer cell lines were treated with Rikkunshito, and cellular viability, gene expressions and epithelial-mesenchymal transition (EMT) status were investigated. To investigate the involvement of SIRT1 by Rikkunshito in SKOV3 cancer cells, endogenous expression of SIRT1 was depleted using small interfering RNA (siRNA). Treatment with Rikkunshito elevated ghrelin, GHSR1a and SIRT1, while cellular viability was decreased. The treatment of Rikkunshito also inhibited cellular migration and invasion status in a dose-dependent manner, and these effects were translated to the enhanced EMT status, although the role of SIRT1 was not determined. Our study revealed a novel function of Rikkunshito in enhancing EMT status of ovarian cancer cells. Therefore, we would like to propose that Rikkunshito may be used as a novel adjunctive therapy in chemotherapy of ovarian cancer because platinum-based chemotherapy frequently used for the treatment of ovarian cancer inevitably impairs appetite.

An evolving paradigm of cancer stem cell hierarchies: therapeutic implications

Over a decade of research has confirmed the critical role of cancer stem-like cells (CSCs) in tumor initiation, chemoresistance, and metastasis. Increasingly, CSC hierarchies have begun to be defined with some recurring themes. This includes evidence that these hierarchies are 'flexible,' with both cell state transitions and dedifferentiation events possible. These findings pose therapeutic hurdles and opportunities. Here, we review cancer stem cell hierarchies and their interactions with the tumor microenvironment. We also discuss the current therapeutic approaches designed to target CSC hierarchies and initial clinical trial results for CSC targeting agents. While cancer stem cell targeted therapies are still in their infancy, we are beginning to see encouraging results that suggest a positive outlook for CSC-targeting approaches.

Effects of Cigarette Smoke and Opium on the Expression of CD9, CD36, and CD68 at mRNA and Protein Levels in Human Macrophage Cell Line THP-1

Cigarette smoking and opium use are risk factors for coronary artery disease (CAD). It has been known that scavenger receptors such as CD36 and CD68 play critical roles in the pathogenesis of CAD. CD9, as a member of the tetraspanin, has been shown to interact with scavenger receptors. The aim of this study was to investigate the effects of these risk factors on expression levels of CD9, CD36, and CD68 on the THP-1 cell line. The THP-1 cell line treated with cigarette smoke extract (CSE( and opium, both individually and combinatory, in 24 h incubation. The protein and mRNA levels of CD9, CD36, and CD68 were evaluated by flow cytometry and quantitative reverse transcription-Polymerase Chain Reaction (qRT-PCR) techniques, respectively. CD36 and CD68 mRNA and protein expression levels were significantly increased in the cells treated with cigarette smoke extract compared to the control (p<0.001 in mRNA expression levels and p=0.016 and p=0.012 in protein expression levels, respectively). The CSE increased the level of CD9 protein expression compared to the control group (p=0.041) on the human macrophage cell line THP-1. No significant differences were observed in the CD9, CD36, and CD68 gene expression and at the protein levels between opium-treated THP-1 cells and controls. In conclusion, cigarettes by increasing the levels of CD36, CD68, and CD9 can be a risk factor in the development of many inflammatory diseases, including cardiovascular diseases, chronic obstructive pulmonary disease (COPD) and lung carcinoma.

Butyrophilin3A proteins and Vγ9Vδ2 T cell activation

Despite playing critical roles in the immune response and having significant potential in immunotherapy, γδ T cells have garnered little of the limelight. One major reason for this paradox is that their antigen recognition mechanisms are largely unknown, limiting our understanding of their biology and our potential to modulate their activity. One of the best-studied γδ subsets is the human Vγ9Vδ2T cell population, which predominates in peripheral blood and can combat both microbial infections and cancers. Although it has been known for decades that Vγ9Vδ2T cells respond to the presence of small pyrophosphate-based metabolites, collectively named phosphoantigens (pAgs), derived from microbial sources or malignant cells, the molecular basis for this response has been unclear. A major breakthrough in this area came with the identification of the Butyrophilin 3A (BTN3A) proteins, members of the Butyrophilin/Butyrophilin-like protein family, as mediators between pAgs and Vγ9Vδ2T cells. In this article, we review the most recent studies regarding pAg activation of human Vγ9Vδ2T cells, mainly focusing on the role of BTN3A as the pAg sensing molecule, as well as its potential impact on downstream events of the activation process.

Lymphocyte Subpopulations in Patients with Advanced Breast Cancer Submitted to Neoadjuvant Chemotherapy

Aims and background

There is an enhanced immune response in patients with breast cancer after the use of chemotherapy. The objective of this study was therefore to investigate alterations in the number of peripheral lymphocytes in patients with breast cancer after neoadjuvant chemotherapy (NC) and the relationship with prognosis.

Methods

Thirty women were analyzed. Their UICC staging was IIb (only T3N0 included) and III (N3 not included). Sample analysis was performed using flow cytometry before the first cycle and 18 to 21 days after the last cycle of NC. The lymphocyte subsets studied were: T (CD3, CD4, CD8), B (CD19, CD23), natural killer (NK) (CD56, CD16), and interleukin-2 (CD25). CD3, CD56, CD8, and CD16 lymphocytes were analyzed with double marking. After x = 3.8 ± 1.3 cycles of 5-fluorouracil, epirubicin and cyclophosphamide (FEC), 16 patients showed a complete or partial response (group 1). After three cycles 14 showed no response or tumor progression (group 2). A control group of healthy women was used for pretreatment analysis.

Results

Before NC there was a significant increase in B lymphocytes and NK cells in comparison to the control group. After NC there was a significant percentage increase in CD3, CD4, CD8, CD25 and CD3+CD56+ cells and a decrease in CD19, CD23, CD56, CD16 and CD16+CD8+ cells. There was a significant fall in the absolute number of CD4, CD19, CD23, CD56, CD16 and CD16+CD8+ lymphocytes and an increase in GD3+CD56+ lymphocytes. Before NC the ratio CD4/CD8 in group 1 was 2.25 ± 0.5 and in group 2 it was 1.79 ± 0.5 (P <0.05).

Conclusions

Patients with advanced breast cancer showed increases in B and NK lymphocytes. Neoadjuvant chemotherapy (FEC) caused an increase in CD3+CD56+ and a decrease in B lymphocytes. Patients with an increased CD4/CD8 ratio have a better chance of responding to neoadjuvant chemotherapy.

Checkpoint inhibitors in hematological malignancies

Inhibitory molecules such as PD-1, CTLA-4, LAG-3, or TIM-3 play a role to keep a balance in immune function. However, many cancers exploit such molecules to escape immune surveillance. Accumulating data support that their functions are dysregulated in lymphoid neoplasms, including plasma cell myeloma, myelodysplastic syndrome, and acute myeloid leukemia. In lymphoid neoplasms, aberrations in 9p24.1 (PD-L1, PD-L2, and JAK2 locus), latent Epstein-Barr virus infection, PD-L1 3'-untranslated region disruption, and constitutive JAK-STAT pathway are known mechanisms to induce PD-L1 expression in lymphoma cells. Clinical trials demonstrated that PD-1 blockade is an attractive way to restore host's immune function in hematological malignancies, particularly classical Hodgkin lymphoma. Numerous clinical trials exploring PD-1 blockade as a single therapy or in combination with other immune checkpoint inhibitors in patients with hematologic cancers are under way. Although impressive clinical response is observed with immune checkpoint inhibitors in patients with certain cancers, not all patients respond to immune checkpoint inhibitors. Therefore, to identify best candidates who would have excellent response to checkpoint inhibitors is of utmost importance. Several possible biomarkers are available, but consensus has not been made and pursuit to discover the best biomarker is ongoing.

The Potential Role of Inhibitory Receptors in the Treatment of Psoriasis

Psoriasis is a common autoimmune disorder that affects the skin. Approximately 30% of individuals with psoriasis will develop inflammatory arthritis, often in the setting of human leukocyte antigen B27. Both forms of disease are thought to be the result of prolonged inflammation mediated by T lymphocytes, dendritic cells, and keratinocytes. While there are treatments aimed at immunomodulation, targeting T cell co-inhibitory receptors signaling pathways may provide therapeutic benefit. This review will discuss in detail four T cell co-inhibitory receptors and their potential application for the treatment of psoriasis and psoriatic arthritis.

Sitagliptin but not alpha glucosidase inhibitor reduced the serum soluble CD163, a marker for activated macrophage, in individuals with type 2 diabetes mellitus

AIMS

Dipeptidyl peptidase-4 inhibitor (DPP-4i) is commonly used worldwide for the treatment of type 2 diabetes mellitus. In addition to its hypoglycemic activity, DPP-4i might have anti-inflammatory effects. In this study we examined the effects of DPP-4i on the serum levels of soluble CD163 (sCD163), a marker for activated macrophages, in individuals with type 2 diabetes mellitus. We compared these anti-inflammatory effects with those of α glucosidase inhibitor (αGI).

METHODS

Japanese patients with type 2 diabetes mellitus who were stably maintained on ≤2mg/day glimepiride alone were recruited and randomly assigned to receive additional sitagliptin (n=37) or αGI (n=37). Levels of sCD163 were measured before the addition and after a 24-week treatment period.

RESULTS

Addition of sitagliptin significantly reduced the serum sCD163 (632 vs. 575ng/mL, p<0.05), while αGI did not display this effect (624 vs. 607ng/mL). The changes in levels of sCD163 were not related to changes in either HbA1c or body mass index (BMI).

CONCLUSIONS

Our results suggested that DPP-4i might exert anti-inflammatory effects in individuals with type 2 diabetes mellitus, which are independent of its effects on glycemia and BMI.

Characterization of hepcidin response to holotransferrin in novel recombinant TfR1 HepG2 cells

Hepcidin is the key regulator of systemic iron homeostasis. The iron-sensing mechanisms and the role of intracellular iron in modulating hepatic hepcidin secretion are unclear. Therefore, we created a novel cell line, recombinant-TfR1 HepG2, expressing iron-response-element-independent TFRC mRNA to promote cellular iron-overload and examined the effect of excess holotransferrin (5g/L) on cell-surface TfR1, iron content, hepcidin secretion and mRNA expressions of TFRC, HAMP, SLC40A1, HFE and TFR2. Results showed that the recombinant cells exceeded levels of cell-surface TfR1 in wild-type cells under basal (2.8-fold; p<0.03) and holotransferrin-supplemented conditions for 24h and 48h (4.4- and 7.5-fold, respectively; p<0.01). Also, these cells showed higher intracellular iron content than wild-type cells under basal (3-fold; p<0.03) and holotransferrin-supplemented conditions (6.6-fold at 4h; p<0.01). However, hepcidin secretion was not higher than wild-type cells. Moreover, holotransferrin treatment to recombinant cells did not elevate HAMP responses compared to untreated or wild-type cells. In conclusion, increased intracellular iron content in recombinant cells did not increase hepcidin responses compared to wild-type cells, resembling hemochromatosis. Furthermore, TFR2 expression altered within 4h of treatment, while HFE expression altered later at 24h and 48h, suggesting that TFR2 may function prior to HFE in HAMP regulation.

[Progress on anti-tumor molecular mechanisms of dihydroartemisinin]

Artemisinin is an anti-malarial drug with poor water solubility and oral absorption; so a variety of derivatives based on the parent nucleus have been developed. Compared with artemisinin, dihydroartemisinin (DHA) has a stronger anti-malaria activity, and has the advantages of high metabolic rate and better water solubility. Recent studies have discovered that DHA has a good inhibitory effect on tumor cells, which is closely related to the peroxide bridge in its molecular structure. Since tumor cells need more Fe³⁺ than normal cells, there are a large number of transferrin receptors on the tumor cell membrane. DHA can break the peroxide bridge in the presence of Fe²⁺, and the free radicals generated can play its lethal effect on tumor cells. In addition, DHA can promote endocytosis of transferrin receptor, and thus prevent cancer cells from taking Fe³⁺ from microenvironment. This article reviews the anti-tumor molecular mechanism of DHA, including accelerating oxidative damage, inducing apoptosis, inhibiting the growth, proliferation and invasion of tumor cells, reversing tumor multidrug resistance.

CB1R antagonist increases hepatic insulin clearance in fat-fed dogs likely via upregulation of liver adiponectin receptors

The improvement of hepatic insulin sensitivity by the cannabinoid receptor 1 (CB1R) antagonist rimonabant (RIM) has been recently been reported to be due to upregulation of adiponectin. Several studies demonstrated that improvement in insulin clearance accompanies the enhancement of hepatic insulin sensitivity. However, the effects of RIM on hepatic insulin clearance (HIC) have not been fully explored. The aim of this study was to explore the molecular mechanism(s) by which RIM affects HIC, specifically to determine whether upregulation of liver adiponectin receptors (ADRs) and other key genes regulated by adiponectin mediate the effects. To induce insulin resistance in skeletal muscle and liver, dogs were fed a hypercaloric high-fat diet (HFD) for 6 wk. Thereafter, while still maintained on a HFD, animals received RIM (HFD+RIM; n = 11) or placebo (HFD+PL; n = 9) for an additional 16 wk. HIC, calculated as the metabolic clearance rate (MCR), was estimated from the euglycemic-hyperinsulinemic clamp. The HFD+PL group showed a decrease in MCR; in contrast, the HFD+RIM group increased MCR. Consistently, the expression of genes involved in HIC, CEACAM-1 and IDE, as well as gene expression of liver ADRs, were increased in the HFD+RIM group, but not in the HFD+PL group. We also found a positive correlation between CEACAM-1 and the insulin-degrading enzyme IDE with ADRs. Interestingly, expression of liver genes regulated by adiponectin and involved in lipid oxidation were increased in the HFD+RIM group. We conclude that in fat-fed dogs RIM enhances HIC, which appears to be linked to an upregulation of the adiponectin pathway.

Response of Human T Cells to Tetanus Neurotoxin HCC Sub-Domain: T Cell Cytokine Production and Activation Marker Induced by HCC

Tetanus is caused by the tetanus neurotoxin (TeNT), a 150 kDa single polypeptide molecule which is cleaved into active two-chain molecules composed of a 50 kDa N-terminal light (L) and a 100 kDa C-terminal heavy (H) chains. Fragment C is further subdivided into two subdomains: the proximal HCN  subdomain and the extreme carboxy subdomain, HCC. HCC is considered as an immunodominant part of TeNT and is responsible for TeNT binding activity to neurons.In the present study, we investigated the ability of recombinant HCC(r HCC) to induce T cell activation. Our results showed that recombinant HCC has a stimulatory effect on IFN-γ secretion by T cells after 48h co-incubation in the presence of anti-TLR-2 Ab. Also, Hcc can induce the expression of CD69 on T cells.Our finding indicated that stimulatory effects of HCC on T cells are TLR-2 independent and anti-TLR-2 inhibitory antibody fails to neutralize HCC stimulatory effects on T cells.Furthermore, HCC  is critical for immunogenic activity of TeNT and is able to induce T cells through TLR-2 independent pathway.

Histomorphological and Immunophenotypic Features of Pill-Induced Esophagitis

The aim of this study was to investigate histomorphological and immunophenotypic features in pill-induced esophagitis. We comparatively evaluated the histomorphological, immunophenotypic features of pill-induced esophagitis vs. reflux esophagitis, as well as clinical information and endoscopic findings. Fifty-two tissue pieces from 22 cases of pill-induced esophagitis, 46 pieces from 20 reflux esophagitis, and 16 pieces from 14 control samples were subjected to immunohistochemistry for inflammatory infiltrates (CD3 for T lymphocyte, CD20 for B lymphocyte, CD56 for NK cell, CD68 for macrophage, CD117 for mast cell) and eosinophil chemotaxis-associated proteins (Erk, leptin, leptin receptor, pSTAT3, phospho-mTOR). As a result, Histomorphology showed that a diffuse pattern of dilated intercellular spaces was more frequently observed in pill-induced esophagitis, while reactive atypia and subepithelial papillary elongation were more often found in reflux esophagitis (P < 0.05, respectively). Interestingly, intraepithelial eosinophilic microabscess, intraepithelial pustule and diffuse pattern of dilated intercellular spaces were observed in 14% (3 cases), 9% (2 cases) and 32% (7 cases) of pill-induced esophagitis, respectively, but in no cases of reflux esophagitis. Regarding intraepithelial inflammatory infiltrates in pill-induced esophagitis, T lymphocytes were the most common cells, followed by eosinophil; 11 and 7 in one x400 power field, respectively. Intraepithelial pSTAT3-positive pattern was more frequently observed in pill-induced esophagitis than in reflux esophagitis, at 45% (10 cases) versus 10% (2 cases), respectively (P < 0.05). Considering the distal esophageal lesion only, intraepithelial pustule, diffuse dilated intercellular spaces and stromal macrophages were more frequently found in distal pill-induced esophagitis, whereas reactive atypia and intraepithelial mast cells in reflux esophagitis (P < 0.05, respectively). In conclusion, diffuse dilated intercellular spaces, intraepithelial eosinophil microabscess, pustule, T lymphocytes, eosinophils, and pSTAT3 positivity can be added to histopathological features of pill-induced esophagitis, other than non-specific ulcer. Besides, distal pill-induced esophagitis may be histopathologically differentiated from reflux esophagitis.

[Endoglin (CD105)--a target for visualization and anti-angiogenic therapy for malignant tumors]

Drugs currently used for anti-angiogenic therapy which are based on monoclonal antibodies to VEGF and its receptors are of limited efficiency. Endoglin (CD105) is a protein receptor of TGF-beta superfamily involved in ligand binding and signal transduction regulating VEGF-independent mechanisms of angiogenesis. CD105 is highly expressed on membranes of endothelial cells of vessels in growing tumors. It plays a crucial role in determination the state of activation or quiescence of endotheliocytes. CD105 is present also on membranes of tumor stromal cells (macrophages, fibroblasts, pericytes). High density of CD105-positive microvessels in tumors corresponds with its aggressivness, spreading to regional lymph nodes and poor prognosis. In patients with progressing tumors soluble form of endoglin in peripheral blood may be detected. Monoclonal antibodies to CD105 and their derivatives are regarded as a basis for creation of new generation of anti-angiogenic reagents for visualization of tumor vessels, for direct effect on endothelium or for targeted drugs delivery to growing tumors.

Hyperglycemia impairs cytotrophoblast function via stress signaling

OBJECTIVE

Diabetes mellitus is a risk factor for preeclampsia. Cytotrophoblast (CTB) invasion is facilitated from the conversion of plasminogen to plasmin by urokinase plasminogen activator (uPA), regulated by plasminogen activator inhibitor 1 (PAI-1), and may be inhibited in preeclampsia. This study assessed signaling mechanisms of hyperglycemia-induced CTB dysfunction.

STUDY DESIGN

Human CTBs were treated with 45, 135, 225, 495, or 945 mg/dL glucose for 48 hours. Some cells were pretreated with a p38 inhibitor (SB203580) or a peroxisome proliferator-activated receptor-gamma (PPAR-γ) ligand (rosiglitazone). Expression of uPA, PAI-1, and PPAR-γ levels and p38 mitogen-activated protein kinase phosphorylation were measured by Western blot in cell lysates. Messenger ribonucleic acid of uPA and PAI-1 was measured by quantitative polymerase chain reaction. Levels of interleukin-6, angiogenic (vascular endothelial growth factor [VEGF], placenta growth factor [PlGF]) and antiangiogenic factors (soluble fms-like tyrosine kinase-1 [sFlt-1], soluble endoglin [sEng]) were measured in the media by enzyme-linked immunosorbent assay kits. Statistical comparisons were performed using analysis of variance with a Duncan's post-hoc test.

RESULTS

Both uPA and PAI-1 protein and messenger ribonucleic acid were down-regulated (P < .05) in CTBs treated with 135 mg/dL glucose or greater compared with basal (45 mg/dL). The sEng, sFlt-1, and interleukin-6 were up-regulated, whereas the VEGF and PlGF were down-regulated by 135 mg/dL glucose or greater. p38 phosphorylation and PPAR-γ were up-regulated (P < .05) in hyperglycemia-treated CTBs. The SB203580 or rosiglitazone pretreatment showed an attenuation of glucose-induced down-regulation of uPA and PAI-1.

CONCLUSION

Hyperglycemia disrupts the invasive profile of CTB by decreasing uPA and PAI-1 expression; down-regulating VEGF and PlGF; and up-regulating sEng, sFlt-1, and interleukin-6. Attenuation of CTB dysfunction by SB203580 or rosiglitazone pretreatment suggests the involvement of stress signaling.

Initial transient accumulation of M2 macrophage-associated molecule-expressing cells after pulpotomy with mineral trioxide aggregate in rat molars

INTRODUCTION

M2 (alternatively activated) macrophages are known to participate in wound healing and tissue repair. This study aimed to analyze the temporospatial changes in the distribution and density of M2 macrophage-associated molecule-expressing cells after pulpotomy with mineral trioxide aggregate (MTA) in rat molars to ascertain the role played by M2 macrophages in the healing of MTA-capped pulp tissue.

METHODS

The maxillary first molars of 8-week-old Wistar rats were pulpotomized and capped with MTA. After 1-14 days, the teeth were examined after hematoxylin-eosin staining or immunoperoxidase staining of CD68 (a general macrophage marker) and M2 macrophage markers (CD163 and CD204). The density of positively stained cells was enumerated in the surface and inner regions (0-100 μm and 300-400 μm, respectively, from the wound surface).

RESULTS

MTA capping initially caused mild inflammatory changes and the formation of a degenerative layer followed by progressive new matrix formation and calcified bridging. At 1-2 days, CD68-, CD163-, and CD204-positive cells started to accumulate beneath the degenerative layer, and the density of these cells was significantly higher in the surface region than in the inner region (P < .05). From 7 days onward, the 3 types of cells displayed an almost normal distribution beneath the newly formed dentinlike matrix.

CONCLUSIONS

After the pulpotomy of rat molars with MTA, M2 macrophage-associated molecule-expressing cells transiently accumulated beneath the degenerative layer under the MTA. This suggests that M2 macrophages participate in the initial phases of the healing of MTA-capped pulp tissue.

Piperlonguminine downregulates endothelial protein C receptor shedding in vitro and in vivo

Endothelial cell protein C receptor (EPCR) plays an important role in coagulation and inflammation. EPCR can be shed from the cell surface, and this is mediated by tumor necrosis factor-α-converting enzyme (TACE). Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit antihyperlipidemic, antiplatelet, and antimelanogenesis activities. However, little is known about the effects of PL on EPCR shedding. Here, we investigated this issue by monitoring the effects of PL on phorbol-12-myristate 13-acetate (PMA) and on cecal ligation and puncture (CLP)-mediated EPCR shedding and underlying mechanisms. PL induced potent inhibition of PMA, and CLP induced EPCR shedding through suppression of TACE expression. And treatment with PL resulted in reduced PMA-stimulated phosphorylation of p38, extracellular regulated kinases (ERK) 1/2, and c-Jun N-terminal kinase (JNK). Given these results, PL might have potential as an anti-sEPCR shedding reagent against PMA- and CLP-mediated EPCR shedding.

[Morpho-functional reaction of spleen natural killer cells and macrophages to melatonin administration to the animals kept on different illumination regimens]

The aim this investigation was to study the changes in the numbers of spleen CD57+ and CD68+ cells (natural killer cells and macrophages respectively) after melatonin administration to the animals kept on different illumination regimens. The experimental animals were given melatonin in dose of 0.03 mg per day for 2 and 4 weeks under conditions of natural illumination or artificial darkening. Spleen paraffin sections were stained using immunohistochemical methods for detection of CD57+ and CD68+ cells. It was shown that long-term administration of melatonin under conditions of natural illumination had an immunosuppressive effect, that was manifested by the depopulation of the marginal zones, white pulp and all the zones of the red pulp, parenchyma loosening and denudation of the reticular stroma of the organ. However, long-term hormone administration under conditions of artificial darkening had an immunostimulatory effect as evidenced by the increased inflow of immunocompetent cells into the spleen, their migration from the white pulp into the marginal zones and emigration into peripheral blood flow, concomitant with the increase in the number of lymphoid nodules. The number of CD57+ and CD68+ cells was increased in splenic periarterial lymphoid sheaths and decreased in B-dependent zones of the organ.

[Melanoma: a new therapeutic era]

Melanoma is the cancer with the fastest incidence increase in Switzerland. 30% of the cases arise before the age of 50 years. Once metastatic, the median survival under current systemic therapies is about 8 months, with less than 5% of patients alive at 5 years. Many efforts in the understanding of cellular biology, intracellular signaling pathways, as well as the role of cellular immunity have been made in the recent years. This has resulted in the development of novel and very promising therapies. In this review, we will cover the results obtained with targeted therapies such as "tyrosin kinase inhibitors" (TKI), as well as those obtained with a monoclonal antibody directed against the CTLA-4 receptor of lymphocytes.

XIAP antisense oligonucleotide (AEG35156) achieves target knockdown and induces apoptosis preferentially in CD34+38- cells in a phase 1/2 study of patients with relapsed/refractory AML

XIAP, a potent caspase inhibitor, is highly expressed in acute myeloid leukemia (AML) cells and contributes to chemoresistance. A multi-center phase 1/2 trial of XIAP antisense oligonucleotide AEG35156 in combination with idarubicin/cytarabine was conducted in 56 patients with relapsed/refractory AML. Herein we report the pharmacodynamic studies of the patients enrolled at M. D. Anderson Cancer Center. A total of 13 patients were enrolled in our institution: five in phase 1 (12-350 mg/m² AEG35156) and eight in phase 2 (350 mg/m² AEG35156) of the protocol. AEG35156 was administered on 3 consecutive days and then weekly up to a maximum of 35 days. Blood samples were collected from patients on days 1 through 5 and on day 28-35 post-chemotherapy for detection of XIAP levels and apoptosis. AEG35156 treatment led to dose-dependent decreases of XIAP mRNA levels (42-100% reduction in phase 2 patients). XIAP protein levels were reduced in all five samples measured. Apoptosis induction was detected in 1/4 phase 1 and 4/5 phase 2 patients. Importantly, apoptosis was most pronounced in CD34+38- AML stem cells and all phase 2 patients showing apoptosis induction in CD34+38- cells achieved response. We conclude that at 350 mg/m², AEG35156 is effective in knocking down XIAP in circulating blasts accompanied by the preferential induction of apoptosis in CD34+38- AML stem cells.

Diesel exhaust particle exposure causes redistribution of endothelial tube VE-cadherin

Whether diesel exhaust particles (DEPs) potentially have a direct effect on capillary endothelia was examined by following the adherens junction component, vascular endothelial cell cadherin (VE-cadherin). This molecule is incorporated into endothelial adherens junctions at the cell surface, where it forms homodimeric associations with adjacent cells and contributes to the barrier function of the vasculature (Dejana et al., 2008; Venkiteswaran et al., 2002; Villasante et al., 2007). Human umbilical vein endothelial cells (HUVECs) that were pre-formed into capillary-like tube networks in vitro were exposed to DEPs for 24h. After exposure, the integrity of VE-cadherin in adherens junctions was assessed by immunofluorescence analysis, and demonstrated that increasing concentrations of DEPs caused increasing redistribution of VE-cadherin away from the cell-cell junctions toward intracellular locations. Since HUVEC tube networks are three-dimensional structures, whether particles entered the endothelial cells or tubular lumens was also examined. The data indicate that translocation of the particles does occur. The results, obtained in a setting that removes the confounding effects of inflammatory cells or blood components, suggest that if DEPs encounter alveolar capillaries in vivo, they may be able to directly affect the endothelial cell-cell junctions.

Onionin A from Allium cepa inhibits macrophage activation

Onionin A (1), a new, stable, sulfur-containing compound, was isolated from acetone extracts of bulbs of onion (Allium cepa), and its structure was characterized as 3,4-dimethyl-5-(1E-propenyl)-tetrahydrothiophen-2-sulfoxide-S-oxide, on the basis of the results of spectroscopic analysis. This compound showed the potential to suppress tumor-cell proliferation by inhibiting the polarization of M2 alternatively activated macrophages.

The human cancer antigen mesothelin is more efficiently presented to the mouse immune system when targeted to the DEC-205/CD205 receptor on dendritic cells

To develop a tumor vaccine directly targeting tumor antigen to dendritic cells in situ, we engineered human mesothelin (MSLN) into an antibody specific for mouse DEC-205, a receptor for antigen presentation. We then characterized both T cell and humoral responses to human MSLN and compared immunizing efficacy of DEC-205-targeted MSLN to nontargeted protein after a single-dose immunization. Targeting human MSLN to DEC-205 receptor induced stronger CD4(+) T-cell responses compared to high doses of mesothelin protein. Approximately 0.5% CD4(+) T cells were primed to produce IFN-gamma, tumor necrosis factor-alpha, and IL-2 via intracellular cytokine staining, and the T cells also could proliferate rapidly. The immune response exhibited breadth because the primed CD4(+) T cells responded to at least three epitopes in the H-2(b) background. Targeting MSLN protein to DEC-205 receptor also resulted in cross-presentation to CD8(+) T cells. Antibody responses against human MSLN were also detected in serum from primed mice by ELISA assays. In summary, targeting of MSLN to DEC-205 improves the induction of CD4(+) and CD8(+) T-cell immunity accompanied by an antibody response. DEC-205-targeting could be valuable for enhancing immunity to MSLN in cancers where this nonmutated protein is expressed.

Exposure to cigarette smoke suppresses IL-15 generation and its regulatory NK cell functions in poly I:C-augmented human PBMCs

Both NK cells and IL-15 play crucial roles in innate immunity against viral infections and cancer. Cigarette smoke is known to increase susceptibility to infections and certain cancers. Interleukin (IL)-15 plays an important role in immune responses by regulating proliferation, survival and functions of NK cells. Here, we examined the impact of cigarette smoke on IL-15 production and IL-15 mediated NK cell functions in human PBMCs. We report that cigarette smoke significantly suppresses the induction of IL-15 by poly I:C in human PBMCs. Serum IL-15 levels among smokers was significantly lower than non-smokers. In contrast to a profound increases in intracellular IL-15/IL-15Ralpha in poly I:C-treated PBMCs, exposure of PBMCs to smoke-conditioned media (SCM) diminished the IL-15/IL-15Ralpha production. We examined if inhibition of IL-15 production could lead to less NK cell activation. Interestingly, SCM-treated PBMCs had diminished up-regulation of NK cell activation marker, CD69, but not NKG2D compared with controls after poly I:C stimulation. We then confirmed by using IL-15 neutralizing antibody as well as exogenous IL-15 that the ploy I:C-induced NK cells activation was IL-15 mediated. More importantly, cigarette smoke significantly impaired NK cell cytolytic potential to kill K562 cancer cells which was found to be IL-15 mediated. The inhibition of IL-15 and its regulatory NK cell activities were linked to attenuated STAT3 and STAT5, but not ERK1/2 phosphorylations. We demonstrate, for the first time, that cigarette smoke compromises IL-15 production and as a result NK cell function which could link to the higher incidence of cancers or viral infections observed among smokers.

Retinoic Acid Receptor Antagonist Inhibits CD38 Antigen Expression on Human Hematopoietic CellsIn Vitro

The CD34+ CD38- subset of human hematopoietic stem cells are crucial for long-term ex-vivo expansion; conditions that decreased this specific sub-population reduced the self-renewal capacity and shortened the duration of the proliferative phase of the culture. Retinoids, such as all-trans retinoic acid (ATRA), have been shown to induce CD38 expression. ATRA present in serum may be responsible for the high CD38 of cells grown in serum-containing medium. In the present study we analyzed the effects of AGN 194310, a retinoic acid receptor pan-antagonist, on CD38 expression of human hematopoietic cells. Normal cells (cord blood derived CD34+ cells) and abnormal cells (myeloid leukemic lines) were studied when grown in either serum-containing or serum-free media. The results showed that both serum and ATRA enhanced differentiation and, thereby, reduced the proportion of CD34+ CD38- cells and total CD34+ cell expansion. AGN reversed these effects of serum and ATRA: it delayed differentiation and increased CD34+ CD38- cells. These results suggest that physiological ATRA levels in serum may prevent efficient cell expansion. AGN, by neutralizing ATRA, improves cell expansion in serum-containing cultures, thus making AGN a useful agent for ex vivo expansion of stem cells and other specific sub-populations for research and clinical use.

Targeted treatment of acute myeloid leukemia in older adults: role of gemtuzumab ozogamicin

As the overall prognosis and treatment response rate to standard chemotherapy for acute myeloid leukemia (AML) remains poor in the older adult population, there is a need for more effective therapeutic agents with lower toxicity profiles that can be offered to these patients. Gemtuzumab ozogamicin (GO) is an anti-CD33 monoclonal antibody that was approved by the US Food and Drug Administration for use as monotherapy in patients 60 years of age and older with relapsed AML. GO consists of a humanized anti-CD33 antibody (hP67.6) which is linked to N-acetyl-gamma calicheamicin 1,2-dimethyl hydrazine dichloride. Once the antibody attaches to the surface antigen, it is rapidly internalized. Calicheamicin, a potent enediyne, is subsequently released and acts as a cytotoxic anti-tumor agent. In this population, GO has an acceptable toxicity and yields response rates approaching 30%. The efficacy of GO as monotherapy and in combination therapy for treatment of both de novo and relapsed AML continues to be investigated.

Translating costimulation blockade to the clinic: lessons learned from three pathways

SUMMARY

As the recognition that costimulatory signals are critical for optimal T-cell activation, proliferation, and differentiation, there has been an explosion in the study of costimulatory molecules and their roles in enhancing anti-donor T-cell responses following transplantation. Here, we focus on the bench-to-beside translation of blocking agents designed to target three critical costimulatory pathways: the CD28/CD80/CD86 pathway, the CD154/CD40 pathway, and the lymphocyte function associated antigen-1/intercellular adhesion molecule pathway. While blockade of each of these pathways proved promising in inhibiting donor-reactive T-cell responses and promoting long-term graft survival in murine models of transplantation, the progression of development of therapeutic agents to block these pathways has each taken a slightly different course. Both logistical and biological pitfalls have accompanied the translation of blockers of all three pathways into clinically applicable therapies, and the development of costimulatory blockade as a substitute for current standard-of-care calcineurin inhibitors has by no means reached completion. Collaboration between both the basic and clinical arenas will further propel the development of costimulation blockers currently in the pipeline, as well as of novel methods to target these critical pathways during transplantation.

Effect of oral erythromycin therapy in patients with aseptic loosening of joint prostheses

There is currently no cure for aseptic loosening (AL) of total joint replacement (TJR) except surgical revision. The purpose of this study was to determine whether oral EM could improve the periprosthetic tissue profiles and reduce serum cytokine production in AL patients who are candidates for surgical revision. We recruited 32 AL patients. AL patients were treated with either EM (600 mg/day, n=18) or placebo (n=14) daily, started one month before surgery and ending on the day of surgery. Blood samples were obtained before EM treatment and during surgery. Periprosthetic tissues and joint fluids were collected during surgery. Our results demonstrate that oral EM reduces the inflammation of periprosthetic tissues, as manifested by the reduction of the numbers of infiltrating cells, CD68+ macrophages, RANKL+ cells, and TRAP+ cells. Remarkable decreases of TNFalpha (9.6-fold), IL-1beta (21.2-fold), and RANKL (76-fold) gene transcripts were observed in periprosthetic tissues of patients treated with oral EM. Serum levels of both TNFalpha and (to a lesser extent) IL-1beta were significantly reduced following EM treatment (p<0.05). Our results suggest that EM represents a biological cure or prevention for those patients who might need repeated revision surgeries and/or show the early signs of progressive osteolysis after TJR.

[Effect of enterosorption on immunologic parameters of patients with colorectal cancer in the postoperative period]

Our investigation was carried out on an assumption that end results among patients radically-treated for colorectal cancer might be improved by use of enteroabsorption. The study group included 17, controls--13 patients with diagnostically verified stage I-III tumors. Mixed sorbent (microcellulose + polysorb) (6g) was administered, once a week, on the average of 20 days after operation. Immunological vigor was assayed 3 weeks after surgery: immunoglobulin levels--by turbodimetric method, cellular profile of lymphocytes--monoclonal antibodies to cell markers CD3, CD4, CD8, CD16 and CD22. As a result of adjuvant treatment CD22 (B-lymphocytes) concentration increased significantly--from 17.70 to 21.66 (22%), while CD16 (innate killers) both in absolute numbers (19%) and by percentage points (9%). Circulating immunocomplex levels in the sorbent-treatment group were significantly lower (37.44 ths units) than in control (48 ths units) (average 28%). No relapse or metastases were reported in either group.

Phosphorylation of the HuR ligand APRIL by casein kinase 2 regulates CD83 expression

Fully mature DC and, to a lesser extent, activated T and B cells express CD83, a surface molecule that appears to fulfil an important role in efficient T-cell activation. Recently, it has been shown that CD83 mRNA is transported from the nucleus to the cytoplasm by an uncommon route, involving the cellular RNA-binding protein HuR and the nuclear export receptor CRM1. Moreover, the shuttle phosphoprotein APRIL (ANP32B) has been shown to be required for HuR-mediated nucleocytoplasmic translocation of the CD83 mRNA by acting as an adaptor that links HuR and CRM1. Here, we are able to report that casein kinase 2 (CK2) phosphorylates APRIL on residue threonine244 (Thr(244)) and demonstrate that the CK2-specific inhibitor 4,5,6,7-tetrabromo-2-azabenzimidazole abolishes CD83 expression in activated Jurkat T cells by interfering with the nucleocytoplasmic translocation of CD83 mRNA. Depletion and knockdown studies demonstrate that the CK2 alpha' subunit is necessary for this regulation, whereas the CK2 alpha subunit seems to be dispensable. Taken together, the data presented significantly extend our knowledge of the complex regulation of CD83 mRNA processing and provides a novel strategy to interfere with CD83 expression.

Regulatory T cells as targets for immunotherapy of autoimmunity and inflammation

Regulatory T (Treg) cells are emerging as key players in the regulation of different immune responses, thereby representing potential candidates for therapeutic interventions in a broad variety of immunological disorders. While the reduction or loss in function would be of benefit during the treatment of cancer, induction and/or expansion of Treg cell function might be helpful to interfere with unwanted immune responses in transplantation medicine, during autoimmunity, allergy and inflammation. However, a better understanding of Treg cell biology is a prerequisite to specifically modulate its function during immune responses in vivo. In the present review we will discuss current concepts on different cell types, components and some novel surface receptors expressed by Treg cells, namely Neuropilin-1, CD83 and G protein-coupled receptor 83 which might represent promising targets for the modulation of Treg cell function in human disease.

Effects of bee venom on the maturation of murine dendritic cells stimulated by LPS

AIM OF STUDY

This study was performed to elicit the effectiveness of bee venom (BV), a traditional immunosuppressive Korean acupuncture agent, on the maturation of dendrtic cells (DCs).

MATERIALS AND METHODS

Immature dendritic cells (iDCs) were generated from mouse bone marrow cells with GM-CSF. After 10 days of initial differentiation, DCs were activated with lipopolysaccharides (LPS) for another 48h in the presence or absence of BV. Surface molecule analysis, intracytoplasmic staining of cytokines, FITC-conjugated antigen uptake, and transwell migration assays were conducted with iDCs and activated DCs.

RESULTS

Up-regulation of costimulatory molecules, typical of mature DCs (mDCs) was inhibited by addition of BV. Pro-inflammatory cytokines were also found to be reduced with BV treatment in LPS-stimulated DC. A decrease in antigen uptake upon the maturation of DC was reversed in low dose BV treated mDC. In addition, BV treated mDC demonstrated reduced directional migration in response to CCL21, a lymphoid chemokine which directs mDC.

CONCLUSIONS

BV may have a therapeutic effect an on abnormally activated immune status, such as autoimmune rheumatoid arthritis, through an immune-modulatory effect on DC.

The B cell in systemic lupus erythaematosus: a rational target for more effective therapy

Current treatment options for systemic lupus erythaematosus (SLE) are diverse and poorly defined, and aggressive therapy can be associated with serious toxicity and tolerability issues. There is, therefore, a need for new and improved treatments to be studied thoroughly in well-designed controlled trials. B Cell dysfunction has emerged as a key pathophysiological component of SLE and is a prime target for the development of new agents for a wide range of lupus severity, including advanced disease. Although many current drugs appear to modify B cell function, the advent of new, targeted therapies offers the hope of improved efficacy and a better long-term tolerability profile.

Armillariella mellea induces maturation of human dendritic cells without induction of cytokine expression

ETHNOPHARMACOLOGICAL RELEVANCE

Armillariella mellea, an edible and medicinal mushroom possessing immuno-modulating potential, has been frequently used for the treatment of infectious diseases or cancers.

AIM OF THE STUDY

In order to elucidate immune-regulatory mechanisms of Armillariella mellea, we investigated the effect of water-soluble components from Armillariella mellea (AME) on the regulation of human dendritic cell (DC) maturation and activation.

MATERIALS AND METHODS

Immature DCs (iDCs) were prepared by differentiating human peripheral blood CD14-positive cells with GM-CSF and IL-4. Then, iDCs were treated with AME at 2-20 microg/ml for 48 h and subjected to flow cytometry to analyze the expression of DC markers. Dextran-FITC uptake assay and enzyme-linked immunosorbent assay were performed to examine the endocytic capacity of AME-stimulated DC and their production of cytokines, respectively.

RESULTS

iDCs stimulated with AME showed representative features during DC maturation such as up-regulated expression of CD80, CD83, CD86, both MHC class I and II molecules, and CD205, with a simultaneous decrease in the expression of CD206 and the endocytic capacity. Interestingly, AME was not able to induce the production of TNF-alpha, IL-12p40, or IL-10, whereas lipopolysaccharides induced a substantial increase of all of the cytokines.

CONCLUSION

Armillariella mellea induces maturation of human DCs through a unique mechanism without inducing cytokine expression.

Recovery of IFN-gamma levels in PBMCs from lepromatous leprosy patients through the synergistic actions of the cytokines IL-12 and IL-18

The shift to the production of a Th1 cytokine profile during an intracellular infection has been shown to depend on antigen presenting cells-derived IL-12 and T-cell-derived IFN-gamma production. IL-18 facilitates Th1 priming in synergy with IL-12 through the stimulation of IFN-gamma production by T cells, B cells, NK cells, macrophages and DCs. A low level of IFN-gamma production in PBMC cultures from lepromatous leprosy patients (LL) has been previously reported by several groups. We evaluated the synthesis of this cytokine after exogenous addition of recombinant IL-12 and IL-18 (IL12/IL18) in order to induce recovery of the IFN-gamma levels with Mycobacterium leprae antigenic stimulation. The aim of this study was to investigate if exogenous addition of IL12/IL18 to PBMC cell cultures in the presence of M. leprae antigens could induce recovery of IFN-gamma levels. We found that IFN-gamma levels in PBMCs cultured from LL patients were reestablished after exogenous addition of exogenous IL12/IL18 and we also observed a diminished IL-18R expression. Although the molecular mechanisms of IL12/IL18 synergy have not been clearly elucidated, we assume that recombinant cytokines can activate several transcription factors that induce IFN-gamma synthesis.

Atherosclerosis development in apolipoprotein E-null mice deficient for CD69

AIMS

Atherosclerosis is a chronic inflammatory disease regulated by immune mechanisms. CD69 is a cell surface receptor rapidly induced after leukocyte activation at sites of chronic inflammation. Genetic disruption of CD69 in the mouse aggravates collagen-induced arthritis (CIA), and partial depletion of CD69-expressing cells with anti-CD69 monoclonal antibody (mAb) prevents CIA development in wild-type mice, suggesting that this receptor negatively modulates immune and inflammatory responses. It has been recently reported that CD69 is upregulated in a large subset of T cells in atherosclerosis-prone apolipoprotein E-null mice (apoE(-/-)). In this study, we investigated whether altering CD69 function affects atherosclerosis development.

METHODS AND RESULTS

We studied native and diet-induced atherosclerosis in apoE(-/-) and doubly deficient apoE(-/-)CD69(-/-) mice and performed expression studies in tissues and primary cells derived from these animals. Plasma cholesterol level was unaffected by CD69 genetic inactivation. Although this genetic manipulation led to an elevated production of interferon gamma and interleukin 10 by activated T cells, apoE(-/-) and apoE(-/-)CD69(-/-) mice fed control and high-fat diet exhibited atheromas of similar size and composition when analysed at different stages of the disease. Likewise, anti-CD69 mAb treatment had no effect on plasma cholesterol and atherosclerosis burden in fat-fed apoE(-/-) mice.

CONCLUSION

In contrast to previous studies highlighting the protective function of CD69 against CIA, an autoimmune inflammatory disease, our results rule out a significant role for CD69 against atherosclerosis in apoE(-/-) mice, an experimental disease model featuring a local inflammatory response triggered and sustained by alterations in lipid homeostasis.

Targeting the tetraspanin CD81 blocks monocyte transmigration and ameliorates EAE

Leukocyte infiltration is a key step in the development of demyelinating lesions in multiple sclerosis (MS), and molecules mediating leukocyte-endothelial interactions represent prime candidates for the development of therapeutic strategies. Here we studied the effects of blocking the integrin-associated tetraspanin CD81 in in vitro and in vivo models for MS. In an in vitro setting mAb against CD81 significantly reduced monocyte transmigration across brain endothelial cell monolayers, both in rodent and human models. Interestingly, leukocyte as well as endothelial CD81 was involved in this inhibitory effect. To assess their therapeutic potential, CD81 mAb were administered to mice suffering from experimental autoimmune encephalomyelitis (EAE). We found that Eat2, but not 2F7 mAb directed against mouse CD81 significantly reduced the development of neurological symptoms of EAE when using a preventive approach. Concomitantly, Eat2 treated animals showed reduced inflammation in the spinal cord. We conclude that CD81 represents a potential therapeutic target to interfere with leukocyte infiltration and ameliorate inflammatory neurological damage in MS.

Dehydroepiandrosterone in adrenal insufficiency and ageing

PURPOSE OF REVIEW

The physiological role of dehydroepiandrosterone remains unclear, and there is continuing controversy on whether dehydroepiandrosterone treatment benefits adrenal-deficient and elderly people with an age-related decline in dehydroepiandrosterone. The objective of this study is to critically review published results and determine whether there is a valid case for dehydroepiandrosterone treatment with advancing age and hypoadrenalism.

RECENT FINDINGS

Oral dehydroepiandrosterone therapy in both elderly and hypoadrenal subjects achieves dehydroepiandrosterone levels comparable to young subjects. Long-term dehydroepiandrosterone replacement in elderly people demonstrated no improvement in body composition, physical performance or any metabolic parameters; however, a modest but inconsistent improvement in bone mineral density occurred at certain sites. Dehydroepiandrosterone replacement in hypoadrenalism modestly improved insulin sensitivity and altered the lipid profile, but it remains uncertain whether these changes improve any patient-important outcomes. Dehydroepiandrosterone replacement in adrenal deficiency inconsistently improves some aspects of mental health.

SUMMARY

Dehydroepiandrosterone replacement increases bone mineral density in elderly subjects; however, the effect is relatively small compared with established therapies for osteoporosis. No additional benefits have been identified for long-term dehydroepiandrosterone replacement, when used in the elderly to prevent or delay ageing. Dehydroepiandrosterone replacement may improve some metabolic variables and measures of psychological well-being in adrenal deficiency, but these benefits are not consistently sustained in long-term therapy. Long-term studies are needed to confirm sustained benefits in adrenal deficiency and establish long-term safety.

Review: anti-CTLA-4 antibody ipilimumab: case studies of clinical response and immune-related adverse events

The immune system is a powerful natural agent against cancer. Cytotoxic T lymphocyte antigen 4 (CTLA-4), a key negative regulator of T-cell responses, can restrict the antitumor immune response. Ipilimumab (MDX-010) is a fully human, monoclonal antibody that overcomes CTLA-4-mediated T-cell suppression to enhance the immune response against tumors. Preclinical and early clinical studies of patients with advanced melanoma show that ipilimumab promotes antitumor activity as monotherapy and in combination with treatments such as chemotherapy, vaccines, or cytokines. Emerging data on the kinetics of response to ipilimumab and associated adverse events are increasing our understanding about how to manage patients treated with this therapy. For example, short-term tumor progression prior to delayed regression has been observed in ipilimumab-treated patients, and objective responses may be of prolonged duration. In some patients clinical improvement manifests as stable disease, which may also extend for months or years. Immune-related adverse events (IRAEs) have been observed in patients after CTLA-4 blockade and most likely reflect the drug mechanism of action and corresponding effects on the immune system. Early clinical data suggest a correlation between IRAEs and response to ipilimumab treatment. This paper briefly reviews the results from several ongoing and completed ipilimumab clinical trials, provides a synopsis of current trials, and presents several cases that demonstrate the kinetics of antitumor responses and the relationship to IRAEs in patients receiving ipilimumab.

Differential suppression of dendritic cell cytokine production by anti-inflammatory drugs

BACKGROUND

Various anti-inflammatory drugs are available for the treatment of skin disorders. In these diseases, untoward immune responses to endogenous and/or environmental antigens are initiated by maturation and polarization of dendritic cells (DC).

OBJECTIVE

To explore the suppressive effects of anti-inflammatory drugs on DC maturation and, in particular, polarization.

METHODS

Exposure of DC to nickel in vitro results in DC maturation and secretion of both type 1 and type 2 cytokines, thereby providing a model to study the effects of anti-inflammatory drugs on DC responses. The inhibitory effects of anti-inflammatory drugs (ciclosporin, dexamethasone, diclofenac, dimethylfumarate, hydrocortisone, lactoferrin, 1-alpha,25-dihydroxyvitamin D3) on DC maturation (CD83, CD86, HLA-DR, CXCL8) and polarization (type 1: IL-12p70, TNF-alpha; type 2: IL-10, CCL17) were studied.

RESULTS

All anti-inflammatory drugs, except for lactoferrin, had inhibitory effects on DC maturation. Hydrocortisone and dexamethasone exclusively suppressed the release of type 1 cytokines. A less pronounced, but similar profile was observed for dimethylfumarate and 1-alpha,25-dihydroxyvitamin D3. Ciclosporin suppressed both type 1 and 2 cytokines. In contrast, diclofenac suppressed only type 2 DC cytokine secretion.

CONCLUSION

The present results give more insight into the pharmacological effects of immunosuppressive drugs on the immune system, and can thereby contribute to a more rational selection of anti-inflammatory drugs for the treatment of inflammatory skin disorders.

Sphingosine-1-phosphate reduces CD4+ T-cell activation in type 1 diabetes through regulation of hypoxia-inducible factor short isoform I.1 and CD69

OBJECTIVES

Non-obese diabetic (NOD) mice develop spontaneous type 1 diabetes. We have shown that sphingosine-1-phosphate (S1P) reduces activation of NOD diabetic endothelium via the S1P1 receptor. In the current study, we tested the hypothesis that S1P could inhibit CD4(+) T-cell activation, further reducing inflammatory events associated with diabetes.

RESEARCH DESIGN AND METHODS

CD4(+) T-cells were isolated from diabetic and nondiabetic NOD mouse splenocytes and treated in the absence or presence of S1P or the S1P1 receptor-specific agonist, SEW2871. Lymphocyte activation was examined using flow cytometry, cytokine bead assays, and a lymphocyte:endothelial adhesion assay.

RESULTS

Diabetic T-cells secreted twofold more gamma-interferon (IFN-gamma) and interleukin-17 than nondiabetic lymphocytes. Pretreatment with either S1P or SEW2871 significantly reduced cytokine secretion by approximately 50%. Flow cytometry analysis showed increased expression of CD69, a marker of lymphocyte activation, on diabetic T-cells. Both S1P and SEW2871 prevented upregulation of CD69 on CD4(+) cells. Quantitative RT-PCR showed that lymphocytes from diabetic NOD mice had 2.5-fold lower hypoxia-inducible factor (HIF)-1alpha short isoform I.1 (HIF1alphaI.1) mRNA levels than control. HIF1alphaI.1 is a negative regulator of lymphocyte activation. S1P significantly increased HIF1alpha I.1 mRNA levels in both control and diabetic groups. IFN-gamma production and surface CD69 expression was significantly increased in lymphocytes of HIF1alphaI.1-deficient mice. S1P did not reduce either CD69 or IFN-gamma expression in lymphocytes from HIF1alphaI.1-deficient mice.

CONCLUSIONS

S1P acts through the S1P1 receptor and HIF1alpha I.1 to negatively regulate T-cell activation, providing a potential therapeutic target for prevention of diabetes and its vascular complications.

[Efficacy of local use of recombinant interferon alpha-2 preparations in combined treatment of recurrent respiratory papillomatosis]

Clinical-immunological examination of 41 patients with recurrent respiratory papillomatosis (RRP) included determination of phenotype CD3, CD4, CD8, CD16, CD25, CD56, HLA-DR in peripheral blood by flow cytofluorimetry, the levels of IFN-gamma, TNF-alpha, GM-CSF, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13 in the laryngeal secretion by multiplex immunoassay. Interferon inhalation therapy was conducted to prevent recurrence in 23 patients after surgical treatment and in 18 patients as monotherapy. The efficacy of the monotherapy was 45.5%. Treatment with IFN-alpha raised the levels of cytokines modulating an immune response by Th1-type (IFN-gamma, IL-12, IL-2) and GM-CSF, and reduced the levels of IL-4, IL-10 and IL-13. Local treatment with recombinant IFN-alpha is effective in aggressive RRP. As prognostic markers of the treatment efficacy may serve baseline high levels of TNF-alpha and IL-4/IFN-gamma index in laryngeal secretion. Treatment efficacy can be assessed by raise of IFN-gamma, IL-2 and IL-12 in combination with reduction of IL-4/IFN-gamma index.

The B7 family and cancer therapy: costimulation and coinhibition

The activation and development of an adaptive immune response is initiated by the engagement of a T-cell antigen receptor by an antigenic peptide-MHC complex. The outcome of this engagement is determined by both positive and negative signals, costimulation and coinhibition, generated mainly by the interaction between the B7 family and their receptor CD28 family. The importance of costimulation and coinhibition of T cells in controlling immune responses is exploited by tumors as immune evasion pathways. Absence of the expression of costimulatory B7 molecules renders tumors invisible to the immune system, whereas enhanced expression of inhibitory B7 molecules protects them from effective T cell destruction. Therefore, the manipulation of these pathways is crucial for developing effective tumor immunotherapy. Translation of our basic knowledge of costimulation and coinhibition into early clinical trials has shown considerable promise.