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Aspergillus fumigatus is the most common cause for invasive fungal infections, a disease associated with high mortality in immune-compromised patients. CD1d-restricted invariant Natural Killer T (iNKT) cells compose a small subset of T cells known to impact the immune response towards various infectious pathogens. To investigate the role of human iNKT cells during A. fumigatus infection, we studied their activation as determined by CD69 expression and cytokine production in response to distinct fungal morphotypes in the presence of different CD1d⁺ antigen presenting cells using flow cytometry and multiplex ELISA. Among CD1d⁺ subpopulations, CD1d⁺CD1c⁺ mDCs showed the highest potential to activate iNKT cells on a per cell basis. The presence of A. fumigatus decreased this effect of CD1d⁺CD1c⁺ mDCs on iNKT cells and led to reduced secretion of TNF-α, G-CSF and RANTES. Production of other Th1 and Th2 cytokines was not affected by the fungus, suggesting an immune-modulating function for human iNKT cells during A. fumigatus infection.
European Myeloma Network Guidelines for the Management of Multiple Myeloma-related Complications
(2015)
The European Myeloma Network provides recommendations for the management of the most common complications of multiple myeloma. Whole body low-dose computed tomography is more sensitive than conventional radiography in depicting osteolytic disease and thus we recommend it as the novel standard for the detection of lytic lesions in myeloma (grade 1A). Myeloma patients with adequate renal function and bone disease at diagnosis should be treated with zoledronic acid or pamidronate (grade 1A). Symptomatic patients without lytic lesions on conventional radiography can be treated with zoledronic acid (grade 1B), but its advantage is not clear for patients with no bone involvement on computed tomography or magnetic resonance imaging. In asymptomatic myeloma, bisphosphonates are not recommended (grade 1A). Zoledronic acid should be given continuously, but it is not clear if patients who achieve at least a very good partial response benefit from its continuous use (grade 1B). Treatment with erythropoietic-stimulating agents may be initiated in patients with persistent symptomatic anemia (hemoglobin < 10g/dL) in whom other causes of anemia have been excluded (grade 1B). Erythropoietic agents should be stopped after 6-8 weeks if no adequate hemoglobin response is achieved. For renal impairment, bortezomib-based regimens are the current standard of care (grade 1A). For the management of treatment-induced peripheral neuropathy, drug modification is needed (grade 1C). Vaccination against influenza is recommended; vaccination against streptococcus pneumonia and hemophilus influenza is appropriate, but efficacy is not guaranteed due to suboptimal immune response (grade 1C). Prophylactic aciclovir (or valacyclovir) is recommended for patients receiving proteasome inhibitors, autologous or allogeneic transplantation (grade 1A).
Patients with refractory or relapsed and refractory multiple myeloma who no longer receive benefit from novel agents have limited treatment options and short expected survival. del(17p) and t(4;14) are correlated with shortened survival. The phase 3 MM-003 trial demonstrated significant progression-free and overall survival benefits from treatment with pomalidomide plus low-dose dexamethasone compared to high-dose dexamethasone among patients in whom bortezomib and lenalidomide treatment had failed. At an updated median follow-up of 15.4 months, the progression-free survival was 4.0 versus 1.9 months (HR, 0.50; P<0.001), and median overall survival was 13.1 versus 8.1 months (HR, 0.72; P=0.009). Pomalidomide plus low-dose dexamethasone, compared with high-dose dexamethasone, improved progression-free survival in patients with del(17p) (4.6 versus 1.1 months; HR, 0.34; P < 0.001), t(4;14) (2.8 versus 1.9 months; HR, 0.49; P=0.028), and in standard-risk patients (4.2 versus 2.3 months; HR, 0.55; P<0.001). Although the majority of patients treated with high-dose dexamethasone took pomalidomide after discontinuation, the overall survival of patients treated with pomalidomide plus low-dose dexamethasone or highdose dexamethasone was 12.6 versus 7.7 months (HR, 0.45; P=0.008) in patients with del(17p), 7.5 versus 4.9 months (HR, 1.12; P=0.761) in those with t(4;14), and 14.0 versus 9.0 months (HR, 0.85; P=0.380) in standard-risk subjects. The overall response rate was higher in patients treated with pomalidomide plus low-dose dexamethasone than in those treated with high-dose dexamethasone both among standard-risk patients (35.2% versus 9.7%) and those with del(17p) (31.8% versus 4.3%), whereas it was similar in patients with t(4; 14) (15.9% versus 13.3%). The safety of pomalidomide plus low-dose dexamethasone was consistent with initial reports. In conclusion, pomalidomide plus low-dose dexamethasone is efficacious in patients with relapsed/refractory multiple myeloma and del(17p) and/or t(4;14).
Die invasive Aspergillose (IA) z¨ ahlt zu den seltenen, bei immunsupprimierten Patienten
jedoch mit einer hohen Letalit¨ at verbundenen Infektionskrankheiten. Sie wird, wie alle
Aspergillosen, durch den humanpathogenen Schimmelpilz Aspergillus fumigatus ausgel¨ ost.
Bis heute ist die oft nicht effektive Therapie einer IA mit hohen Nebenwirkungen und
Kosten verbunden. Die Entwicklung von Pathogen-spezifischen Immuntherapien soll durch
die Forschung im Bereich der immunologischen Infektionsbiologie vorangetrieben werden.
Fur neuen Erkenntnisse wird die Interaktion von humanen Immunzellen mit ¨ A. fumigatus
analysiert.
In der vorliegenden Studie wurde mit dendritischen Zellen (DCs) gearbeitet, da diese
Pilzmorphologien von A. fumigatus phagozytieren k¨ onnen und uber Antigenpr ¨ ¨ asentation
das adaptive Immunsystem aktivieren. Es wurden aus humanen Monozyten differenzierte DCs (moDCs) verwendet, mit welchen viele Forschergruppen aufgrund ihrer verfugbar ¨
großen Anzahl arbeiten. Allerdings dauert die Generierung von moDCs funf Tage. Aus ¨
dem peripheren Blut entstammende CD1c-positive myeloide DCs (mDCs) oder CD303-
positive plasmazytoide DCs (pDCs) k¨ onnen dagegen direkt nach der Isolation verwendet
werden. Die beiden DC-Populationen werden aus verschiedenen Vorl¨ auferzellen des h¨ amatopoetischen Systems im Knochenmark gebildet. Ihr Ph¨ anotyp und ihre Immunfunktionen
unterscheiden sich untereinander und auch von denen der moDCs.
In Interaktionsstudien konnte analysiert werden, dass die drei verwendeten DC-Subtypen
(moDCs, mDCs, pDCs) unterschiedlich auf A. fumigatus reagieren. moDCs und mDCs reiften in direktem Kontakt zu Aspergillus, sie sekretierten ein relativ ¨ ahnliches Zytokinprofil
und exprimierten die bekannten Aspergillus-Rezeptoren Dectin-1, TLR2 und TLR4. Im
Kontrast dazu verblieben pDCs trotz Aspergillus-Kontakt unreif und sekretierten nahezu
keine Zytokine. Da moDCs und mDCs eine Immunreaktion auf den Pilz zeigten, wurden
sie mit verschiedenen Aspergillus-Antigenen beladen und n¨ aher untersucht.
Bevor verschiedene Aspergillus-Antigene zur Beladung der DCs eingesetzt werden konnten, wurden diese analysiert und aufgereinigt. Hierfur wurde ein routinierter Arbeitsprozess ¨
etabliert. Zwei der vier verfugbaren Proteinantigene waren mit Endotoxin kontaminiert. ¨
Da schon geringe Mengen an Endotoxinen auf DCs einen stimulatorischen Effekt ausubten, ¨
wurden die Proteine mittels Affinit¨ atschromatografie von den verunreinigenden Endotoxinen befreit.
In den Stimulationsexperimenten wirkten die beiden Proteinantigene CcpA und SHMT
immunogen auf moDCs und mDCs. CcpA induzierte eine st¨ arkere Maturierung und Zytokinfreisetzung als SHMT. Auff¨ allig war, dass mDCs im Vergleich zu moDCs die Expression
von MHC Klasse II st¨ arker erh¨ ohten und mehr IL18 freisetzten. Die mit CcpA oder SHMT
beladenen moDCs und mDCs aktivierten autologe T-Zellen zur IFNg Sekretion und zur
Proliferation. Zudem wurden durch die beiden Proteine Aspergillus-spezifische, CD154-
positive T-Zellen induziert. Diese Aspergillus-spezifische Immunogenit¨ at von CcpA und
SHMT macht die beiden Proteine zu interessanten Kandidaten fur einen Vakzinierungs- ¨
Cocktail einer DC-Immuntherapie. Aspergillus Lysat induzierte als weiteres Antigen eine
T-Zell Immunantwort mit CD154-positiven T-Zellen. Zudem war die Proliferation und
IFNg Sekretion von T-Zellen induziert, obwohl moDCs und mDCs nicht reiften und nur
wenige Zytokine sekretierten. Die beiden Aspergillus-Proteine CpcB und fg-gap induzierten die Reifung und Zytokinsekretion von moDCs und mDCs nicht. Demzufolge sind CpcB
und fg-gap fur eine DC-Immuntherapie nicht empfehlenswert. ¨
Ein Vakzinierungs-Cocktail enth¨ alt in der Regel Adjuvantien, welche die Immunreaktion
verst¨ arken. Adjuvante Effekte auf moDCs konnten die getesteten Aspergillus-RezeptorLiganden Zymosan, Pam3CSK4, LPS ultrapur und R848 ausl¨ osen. Hyalurons¨ aure konnte keine Verbesserung der Reifung oder Vitalit¨ at von moDCs und mDCs bewirken. Die
Antigen-bedingte Reifung der DCs fur n ¨ ¨ otige Restimulationen w¨ ahrend der Therapie konnte mittels einer tiefgekuhlten Lagerung in CryoStor Einfriermedium stabil beibehalten ¨
werden.
Die beiden immunogenen Aspergillus-Proteine, die adjuvanten Rezeptor-Agonisten und
die stabile Lagerung in CryoStor k¨ onnen als elementare Grundsteine fur einen Vakzinierungs- ¨
Cocktail einer anti-fungalen DC-Immuntherapie mit moDCs oder mDCs angesehen werden.
Multiple myeloma (MM) is a generally fatal plasma cell cancer that often shows activation of the phosphoinositide 3-kinase/Akt (PI3K/Akt) pathway. Targeted pharmacologic therapies, however, have not yet progressed beyond the clinical trial stage, and given the complexity of the PI3K/Akt signalling system (e.g. multiple protein isoforms, diverse feedback regulation mechanisms, strong variability between patients) it is mandatory to characterise its ramifications in order to better guide informed decisions about the best therapeutic approaches. Here we explore whether serum and glucocorticoid-regulated kinase 3 (SGK3), a potential downstream effector of PI3K, plays a role in oncogenic signalling in MM cells-either in concert with or independent of Akt. SGK3 was expressed in all MM cell lines and in all primary MM samples tested. Four MM cell lines representing a broad range of intrinsic Akt activation (very strong: MM. 1s, moderate: L 363 and JJN-3, absent: AMO-1) were chosen to test the effects of transient SGK3 knockdown alone and in combination with pharmacological inhibition of Akt, PI3K-p110\(\alpha\), or in the context of serum starvation. Although the electroporation protocol led to strong SGK3 depletion for at least 5 days its absence had no substantial effect on the activation status of potential downstream substrates, or on the survival, viability or proliferation of MM cells in all experimental contexts tested. We conclude that it is unlikely that SGK3 plays a significant role for oncogenic signalling in multiple myeloma.
Farnesol, produced by the polymorphic fungus Candida albicans, is the first quorum-sensing molecule discovered in eukaryotes. Its main function is control of C. albicans filamentation, a process closely linked to pathogenesis. In this study, we analyzed the effects of farnesol on innate immune cells known to be important for fungal clearance and protective immunity. Farnesol enhanced the expression of activation markers on monocytes (CD86 and HLA-DR) and neutrophils (CD66b and CD11b) and promoted oxidative burst and the release of proinflammatory cytokines (tumor necrosis factor alpha [TNF-\(\alpha\)] and macrophage inflammatory protein 1 alpha [MIP-1 \(\alpha\)]). However, this activation did not result in enhanced fungal uptake or killing. Furthermore, the differentiation of monocytes to immature dendritic cells (iDC) was significantly affected by farnesol. Several markers important for maturation and antigen presentation like CD1a, CD83, CD86, and CD80 were significantly reduced in the presence of farnesol. Furthermore, farnesol modulated migrational behavior and cytokine release and impaired the ability of DC to induce T cell proliferation. Of major importance was the absence of interleukin 12 (IL-12) induction in iDC generated in the presence of farnesol. Transcriptome analyses revealed a farnesol-induced shift in effector molecule expression and a down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor during monocytes to iDC differentiation. Taken together, our data unveil the ability of farnesol to act as a virulence factor of C. albicans by influencing innate immune cells to promote inflammation and mitigating the Th1 response, which is essential for fungal clearance.
Objectives
Liver biopsies are the current gold standard in non-alcoholic steatohepatitis (NASH) diagnosis. Their invasive nature, however, still carries an increased risk for patients' health. The development of non-invasive diagnostic tools to differentiate between bland steatosis (NAFL) and NASH remains crucial. The aim of this study is the evaluation of investigated circulating microRNAs in combination with new targets in order to optimize the discrimination of NASH patients by non-invasive serum biomarkers.
Methods
Serum profiles of four microRNAs were evaluated in two cohorts consisting of 137 NAFLD patients and 61 healthy controls. In a binary logistic regression model microRNAs of relevance were detected. Correlation of microRNA appearance with known biomarkers like ALT and CK18-Asp396 was evaluated. A simplified scoring model was developed, combining the levels of microRNA in circulation and CK18-Asp396 fragments. Receiver operating characteristics were used to evaluate the potential of discriminating NASH.
Results
The new finding of our study is the different profile of circulating miR-21 in NASH patients (p<0.0001). Also, it validates recently published results of miR-122 and miR-192 to be differentially regulated in NAFL and NASH. Combined microRNA expression profiles with CK18-Asp396 fragment level scoring model had a higher potential of NASH prediction compared to other risk biomarkers (AUROC = 0.83, 95% CI = 0.754-0.908; p<0.001). Evaluation of score model for NAFL (Score = 0) and NASH (Score = 4) had shown high rates of sensitivity (91%) and specificity (83%).
Conclusions
Our study defines candidates for a combined model of miRNAs and CK18-Asp396 levels relevant as a promising expansion for diagnosis and in turn treatment of NASH.
Introduction
Enhanced B cell activity, particularly memory B cells have gained interest in evaluating response during therapies with biologics. CD27-IgD- double-negative (DN) B cells lacking the conventional memory marker CD27 are reported to be part of the memory compartment, however, only scarce data is available for rheumatoid arthritis (RA). We therefore focused on DN B cells in RA, studied their isotypes and modulation during interleukin-6 receptor (IL-6R) inhibition by tocilizumab (TCZ).
Methods
DN B cells were phenotypically analyzed from 40 RA patients during TCZ at baseline week 12, week 24 and 1 year. A single B cell polymerase chain reaction (PCR) approach was used to study Ig receptors, VH gene rearrangements and specific isotypes.
Results
Phenotypic analysis showed a significantly expanded population of DN B cells in RA which contain a heterogeneous mixture of IgG-, IgA- and IgM-expressing cells with a clear dominance of IgG+ cells. DN B cells carry rearranged heavy chain gene sequences with a diversified mutational pattern consistent with memory B cells. In contrast to tumor necrosis factor alpha (TNF-α) inhibition, a significant reduction in mutational frequency of BCR gene rearrangements at week 12, 24 and 1 year (P <0.0001) was observed by in vivo IL-6R inhibition. These changes were observed for all BCR isotypes IgG, IgA and IgM at week 12, 24 and 1 year (P <0.0001). IgA-RF, IgA serum level and IgA+ DN B cells decreased significantly (P <0.05) at week 12 and week 24 during TCZ. Patients with a good European League Against Rheumatism (EULAR) response to TCZ had less DN B cells at baseline as compared to moderate responders (P = 0.006). Univariate logistic regression analysis revealed that the frequency of DN B cells at baseline is inversely correlated to a subsequent good EULAR response (P = 0.024) with an odds ratio of 1.48 (95% confidence interval as 1.05 to 2.06).
Conclusions
In RA, the heterogeneous DN B cell compartment is expanded and dominated by IgG isotype. TCZ can modulate the mutational status of DN Ig isotype receptors over 1 year. Interestingly, the frequency of DN B cells in RA may serve as a baseline predictor of subsequent EULAR response to TCZ.
B-Zellen spielen eine wichtige Rolle in der Pathogenese der Rheumatoiden Arthritis. Seit dem Jahr 2006 ist der Anti-CD20-Antikörper Rituximab, welcher eine passagere B-Zell-Depletion induziert, zur Therapie der Rheumatoiden Arthritis zugelassen. In dieser Arbeit wurde das variable Kappa- und Lambda-Leichtkettenrepertoire der CD19+CD27+ B-Gedächtniszellen bei einer Patientin mit aktiver Rheumatoider Arthritis vor und nach B-Zell-Depletion durch Rituximab verglichen. Hierzu wurden nach der Einzelzellsortierung von mononuklären Zellen des peripheren Blutes die Rearrangements des Kappa- und Lambda-Leichtkettenrepertoires amplifiziert, sequenziert und analysiert. Die gefundenen Daten sprechen für die Neubildung eines diversen, polyklonalen und hochmutierten Kappa- und Lambda-Leichtkettenrepertoires. Somit ist davon auszugehen, dass nach der CD20+ B-Zell-Depletion ein funktionsfähiges Repertoire entsteht, welches keine Restriktion für die Infektabwehr aufweist.
ZUSAMMENFASSUNG
Obwohl diverse Mutationen des NF-κB Systems in Myelomzelllinien und primären Myelomzellen eine pathogenetische Beteiligung andeuten, ist die Relevanz des IKK Komplexes als molekularer Angriffspunkt für die Entwicklung medikamentöser Therapieoptionen noch nicht ausreichend geklärt. Zwar führte die Applikation des IKK-β Inhibitors MLN120b dosisabhängig und längerfristig zu einer Reduktion der Zellviabilität in einer Vielzahl von Myelomzelllinien, doch kann nicht ausgeschlossen werden, dass bei höheren Konzentrationen unspezifische Wirkungen für die beobachteten Effekte (mit-) verantwortlich sind.
Aus diesem Grund erfolgte in der vorliegenden Arbeit eine spezifische Suppression von
IKK-α, IKK-β oder IKK-γ mittels transienter Transfektion von shRNA Expressionsvektoren oder Stealth-siRNA. Es folgte die Charakterisierung der verminderten Zielproteinspiegel mittels Western-Blot und die Messung der Viabilität der Zellen mittels FACS Analysen. Darüber hinaus wurde in TNF-α Stimulationsexperimenten der Effekt der Suppression von IKK-β mittels Stealth-siRNA auf (Phospho-)IκB-α analysiert. Schließlich erfolgte die Applikation des IKK-β Inhibitors
TPCA, dessen Wirkung auf die Zellviabilität und auf die TNF-α-vermittelte Phosphorylierung und Degradation von IκB-α in MM.1S Zellen untersucht wurde.
Die Experimente mit Stealth-siRNA zeigten, dass weder die Suppression von IKK-β, noch die Suppression von IKK-α oder IKK-γ in AMO-1, L363 oder MM.1S eine Verminderung der Zellviabilität bewirken konnte. Auch eine kombinierte Suppression von IKK-α zusammen mit IKK-β in L363 und MM.1S Zellen bewirkte keinen vermehrten Zelltod. Dagegen zeigte die Behandlung von MM.1S Zellen mit hohen Konzentrationen von TPCA einen geringen Effekt auf das Überleben dieser Zellen. Die Suppression von IKK-β mittels Stealth-siRNA in MM.1S konnte nicht die TNF-α vermittelte IκB-α
Phosphorylierung und Degradation verhindern. Sowohl die hohe TNF-α Konzentration von 100ng/ml, als auch eine unvollständige Suppression von IKK-β könnte dazu beigetragen haben. In analogen Experimenten mit TPCA konnte die TNF-α vermittelte IκB-α Phosphorylierung und Degradation dagegen effektiv unterdrückt werden.
In der Zusammenschau der Ergebnisse konnte somit eine potenzielle therapeutische Relevanz des IKK-Komplexes als molekularer Angriffspunkt für eine Myelomtherapie nicht gefunden werden.
Eine noch detailliertere Analyse der Funktionalität des Signalwegs (insbesondere eine Messung der Aktivität der NF-κB Transkriptionsfaktoren im Zellkern) und die Etablierung stabiler und induzierbarer Expressionssysteme für längerfristige Untersuchungen der RNAi Wirkungen in Myelomzellen, stellen weiterführende Wege zu einer umfangreicheren Beurteilung der pathobiologischen und therapeutischen Bedeutung des NF-κB Systems dar. Darüber hinaus sind die das NF-κB System betreffenden Mutationen genauer hinsichtlich ihrer potenziellen Wirkung auf NF-κB unabhängige Signalwege zu untersuchen.