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result(s) for
"Coch, Christoph"
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Monocyte-dependent co-stimulation of cytokine induction in human γδ T cells by TLR8 RNA ligands
2021
Human Vγ9Vδ2 T cells recognize pyrophosphates produced by microbes and transformed cells and play a role in anti-infective immunity and tumor surveillance. Toll-like receptors (TLR) are pattern recognition receptors in innate immune cells which sense microbial structures including nucleic acids. Given that γδ T cells are in clinical development for application in cellular cancer immunotherapy and TLR ligands have potent adjuvant activity, we investigated the co-stimulatory role of selected TLR ligands in γδ T-cell activation. Here we have used recently described RNA ligands for TLR7 and TLR8 together with Vγ9Vδ2 T-cell specific pyrophosphate antigens to analyze the rapid cytokine induction in Vδ2 T cells as well as the accessory cell requirements. While TLR8- as well as TLR7/8-specific RNA did not induce IFN-γ in Vδ2 T cells on their own, they provided strong co-stimulation for Vδ2 T cells within peripheral blood mononuclear cells in the presence of additional T-cell receptor activation. In contrast, TLR7 ligands were ineffective. Purified γδ T cells did not directly respond to TLR8 co-stimulation but required the presence of monocytes. Further experiments revealed a critical role of IL-1β and IL-18, and to a slightly lesser extent of IL-12p70, in the co-stimulation of Vδ2 T cells by TLR8 and TLR7/8 RNA ligands. Results of intracellular cytokine expression were validated by ELISA analysis of cytokines in cell culture supernatants. The cell context-dependent adjuvant activity of TLR8 and TLR7/8 RNA ligands described here might be important for the future optimization of γδ T-cell based cancer immunotherapy.
Journal Article
Sequence-specific activation of the DNA sensor cGAS by Y-form DNA structures as found in primary HIV-1 cDNA
2015
Truncated reverse transcription of HIV RNA produces a single-stranded DNA intermediate with a unique Y-DNA stem-loop structure flanked by unpaired guanines. Schlee and colleagues show this Y-DNA activates cGAS to elicit the production of type I interferon.
Cytosolic DNA that emerges during infection with a retrovirus or DNA virus triggers antiviral type I interferon responses. So far, only double-stranded DNA (dsDNA) over 40 base pairs (bp) in length has been considered immunostimulatory. Here we found that unpaired DNA nucleotides flanking short base-paired DNA stretches, as in stem-loop structures of single-stranded DNA (ssDNA) derived from human immunodeficiency virus type 1 (HIV-1), activated the type I interferon–inducing DNA sensor cGAS in a sequence-dependent manner. DNA structures containing unpaired guanosines flanking short (12- to 20-bp) dsDNA (Y-form DNA) were highly stimulatory and specifically enhanced the enzymatic activity of cGAS. Furthermore, we found that primary HIV-1 reverse transcripts represented the predominant viral cytosolic DNA species during early infection of macrophages and that these ssDNAs were highly immunostimulatory. Collectively, our study identifies unpaired guanosines in Y-form DNA as a highly active, minimal cGAS recognition motif that enables detection of HIV-1 ssDNA.
Journal Article
Aflibercept for choroidal neovascularizations secondary to pseudoxanthoma elasticum: a prospective study
2020
PurposeTo evaluate the use of 2 mg intravitreal aflibercept for treatment of choroidal neovascularization (CNV) secondary to angioid streaks in patients with pseudoxanthoma elasticum (PXE).MethodsIn this 12-month prospective, open-label, uncontrolled, non-randomized interventional clinical trial, 15 PXE patients with CNV (mean age: 53 years, range 22–65) received one initial intravitreal injection of 2 mg aflibercept. Further injections were based on CNV activity at monthly examinations. The primary endpoint was change of best corrected visual acuity (BCVA) after 12 months. Secondary outcomes were change of central retinal thickness (CRT), leakage from CNV, retinal sensitivity, and vision-related quality of life.ResultsBCVA improved from 75.0 ± 10.8 (± SD, Snellen equivalent 20/32) to 79.3 ± 7.3 ETDRS letters (20/32) at final visit (p = 0.083). CRT decreased from 317 ± 81 to 279 ± 51 μm (p = 0.004). Retinal sensitivity on microperimetry changed from 17.8 ± 4.5 to 18.5 ± 4.3 dB (p = 0.103) and vision-related quality of life from a VQF-25 score of 80.7 ± 10.4 to 83.5 ± 14.5 (p = 0.554). The mean number of injections was 6.7 ± 2.6, and 5 participants had persistent or reactivated CNV activity at final visit. The observed adverse events were comparable with studies on aflibercept for other indications.ConclusionThe results of this study indicate that intravitreal aflibercept is a treatment option for CNV secondary to PXE.
Journal Article
Health-related quality of life and neurocognitive functioning with lomustine–temozolomide versus temozolomide in patients with newly diagnosed, MGMT-methylated glioblastoma (CeTeG/NOA-09): a randomised, multicentre, open-label, phase 3 trial
by
Goldbrunner, Roland
,
Stummer, Walter
,
Tzaridis, Theophilos
in
Brain cancer
,
Chemoradiotherapy
,
Chemotherapy
2019
The CeTeG/NOA-09 trial showed significantly longer overall survival with combined lomustine–temozolomide therapy compared with standard temozolomide for patients with glioblastoma with methylated MGMT promoter. The trial also aimed to investigate the effect of lomustine–temozolomide therapy on health-related quality of life (HRQOL) and neurocognitive function, which we report here.
In this randomised, multicentre, open-label, phase 3 trial, newly diagnosed, chemoradiotherapy-naive patients with MGMT-methylated glioblastoma, aged 18–70 years, with a Karnofsky performance score of 70% or higher, were recruited and enrolled at 17 university hospitals in Germany. Patients received standard radiotherapy (60 Gy) and were randomly assigned (1:1, stratified by centre by allocating complete blocks of six to a centre, without masking) to either six 6-week courses of oral combined lomustine (100 mg/m2 on day 1) plus temozolomide (100–200 mg/m2 on days 2–6) or standard oral temozolomide (75 mg/m2 daily during radiotherapy plus six 4-week courses of temozolomide [150–200 mg/m2] on days 1–5, every 4 weeks). The primary endpoint was overall survival. HRQOL, assessed using the European Organisation for Research and Treatment of Cancer (EORTC) quality of life questionnaire core-30 and the EORTC brain cancer module (BN20); and neurocognitive function, assessed using the Mini Mental State Examination (MMSE), plus a neurocognitive test battery (NOA-07), including Trail Making Test A and B (TMT-A and B), working memory tests, and tests for lexical (Controlled Oral Word Association [COWA]) and semantic verbal fluency, were secondary endpoints analysed in the modified intention-to-treat population (mITT; all randomly assigned patients who received at least one dose of study chemotherapy). We used linear mixed-model analyses to investigate differences between treatment groups regarding HRQOL (clinically relevant ≥10 points) and MMSE scores (clinically relevant ≥3 points). The trial is registered with ClinicalTrials.gov, NCT01149109.
Between June 17, 2011 and April 8, 2014, 141 patients were randomly assigned and 129 patients began treatment and were included in the mITT population (63 in the temozolomide and 66 in the lomustine–temozolomide group). Median follow-up for HRQOL (the item global health) was 19·4 months (IQR 7·8–38·6), for MMSE was 15·3 months (4·1–29·6), and for COWA was 11·0 months (0–27·5). We found no significant impairment regarding any item of HRQOL in the lomustine–temozolomide group (difference between the groups for global health 0·30 [95% CI −0·23 to 0·83]; p=0·26). Differences in MMSE were in favour of the temozolomide group (difference −0·11 [95% CI −0·19 to −0·03]; p=0·0058) but were not clinically relevant (1·76/30 points over 4 years). We found no significant difference between the groups in any subtest of the neurocognitive test battery (difference for COWA 0·04 [95% CI −0·01 to 0·09]; p=0·14).
The absence of systematic and clinically relevant changes in HRQOL and neurocognitive function combined with the survival benefit of lomustine–temozolomide versus temozolomide alone suggests that a long-term net clinical benefit exists for patients with newly diagnosed glioblastoma with methylation of the MGMT promoter and supports the use of lomustine–temozolomide as a treatment option for these patients.
German Federal Ministry of Education and Research.
Journal Article
Human Beta Papillomavirus Type 8 E1 and E2 Proteins Suppress the Activation of the RIG-I-Like Receptor MDA5
by
Hufbauer, Martin
,
Akgül, Baki
,
Hagen, Christian
in
Acids
,
Analysis
,
Betapapillomavirus - genetics
2022
Persistent infections of the skin with the human papillomavirus of genus beta (β-HPV) in immunocompetent individuals are asymptomatic, but in immunosuppressed patients, β-HPV infections exhibit much higher viral loads on the skin and are associated with an increased risk of skin cancer. Unlike with HPV16, a high-risk α-HPV, the impact of β-HPV early genes on the innate immune sensing of viral nucleic acids has not been studied. Here, we used primary skin keratinocytes and U2OS cells expressing HPV8 or distinct HPV8 early genes and well-defined ligands of the nucleic-acid-sensing receptors RIG-I, MDA5, TLR3, and STING to analyze a potential functional interaction. We found that primary skin keratinocytes and U2OS cells expressed RIG-I, MDA5, TLR3, and STING, but not TLR7, TLR8, or TLR9. While HPV16-E6 downregulated the expression of RIG-I, MDA5, TLR3, and STING and, in conjunction with HPV16-E7, effectively suppressed type I IFN in response to MDA5 activation, the presence of HPV8 early genes showed little effect on the expression of these immune receptors, except for HPV8-E2, which was associated with an elevated expression of TLR3. Nevertheless, whole HPV8 genome expression, as well as the selective expression of HPV8-E1 or HPV8-E2, was found to suppress MDA5-induced type I IFN and the proinflammatory cytokine IL-6. Furthermore, RNA isolated from HPV8-E2 expressing primary human keratinocytes, but not control cells, stimulated a type I IFN response in peripheral blood mononuclear cells, indicating that the expression of HPV8-E2 in keratinocytes leads to the formation of stimulatory RNA ligands that require the active suppression of immune recognition. These results identify HPV8-E1 and HPV8-E2 as viral proteins that are responsible for the immune escape of β-HPV from the innate recognition of viral nucleic acids, a mechanism that may be necessary for establishing persistent β-HPV infections.
Journal Article
Modulating Placebo Effects in Clinical Trials: Study Team Briefing to Optimize Drug–Placebo Differences
2025
Clinical trials often face challenges with placebo effects that can mask actual drug effects. We evaluated whether briefing the study team members on placebo mechanisms influenced analgesia. In this study, we compared the analgesic effects of oxycodone and placebo in three groups of 32 subjects. The groups were treated by an untrained study team (Arm A), a team trained to maximize (Arm B) and a team trained to minimize placebo effects (Arm C). The primary outcome was the reduction of pain during the cold pressor test, assessed by the area under the pain curve of the visual analog scale before and after blinded administration of oxycodone or placebo. Oxycodone and placebo demonstrated the expected differences in pain reduction across all study arms. Briefing the study team did not significantly affect pain reduction or treatment expectation, regardless of treatment. However, treatment expectations were more pronounced with oxycodone compared to placebo, showing a positive correlation of expectation and treatment effect only in the oxycodone group, possibly reflecting the influence of unblinding due to adverse effects. These findings suggest that a brief training of the study team may not be sufficient to alter treatment expectations and placebo analgesia. This insight will inform future efforts to apply placebo research to optimize blinded trial design and drug treatments in clinical settings. Trial Registration: DRKS 00013586 (German Clinical Trials Register), registered on December, 22nd 2017; URL: https://www.drks.de/drks_web/setLocale_EN.do
Journal Article
Elevated baseline C-reactive protein levels predict poor progression-free survival in sporadic vestibular schwannoma
by
Güresir, Erdem
,
Wach, Johannes
,
Hölzel, Michael
in
2-Methylisoborneol
,
C-reactive protein
,
C-Reactive Protein - metabolism
2022
Background
Recent investigations showed emerging evidence of the role of inflammation in the growth of sporadic vestibular schwannoma (VS). The present retrospective study investigated the impact of systemic inflammation on tumor progression using serum C-reactive protein (CRP) levels in a series of 87 surgically treated sporadic VS patients.
Methods
The optimal cut-off value for CRP was defined as 3.14 mg/dl according to the receiver operating characteristic curve (AUC: 0.70, 95% CI 0.47–0.92). Patient cohort was dichotomized into normal (n = 66; < 3.14 mg/dl) and high baseline (n = 21; ≥ 3.14 mg/dl) CRP groups.
Results
No significant differences in age, sex, comorbidities influencing the systemic inflammatory state, Karnofsky performance status (KPS), tumor size, extent of resection, or MIB-1 index were identified between the two groups defined by the baseline CRP levels. Univariable analysis demonstrated that a high CRP level (≥ 3.14 mg/dl) is significantly associated with a shortened progression-free survival (PFS) (hazard ratio (HR): 6.05, 95% CI 1.15–31.95,
p
= 0.03). Multivariable Cox regression analysis considering age, extent of resection, KPS, tumor size, and baseline CRP confirmed that an elevated CRP level (≥ 3.14 mg/dl) is an independent predictor of shortened PFS (HR: 7.20, 95% CI 1.08–48.14,
p
= 0.04).
Conclusions
The baseline CRP level thus serves as an independent predictor of PFS. Further investigations of the role of inflammation and tumor inflammatory microenvironment in the prediction of prognosis in sporadic VS are needed.
Graphical abstract
Journal Article
PrImary decompressive Craniectomy in AneurySmal Subarachnoid hemOrrhage (PICASSO) trial: study protocol for a randomized controlled trial
by
Güresir, Erdem
,
Brandecker, Simon
,
Mielke, Dorothee
in
Aneurysms
,
Biomedicine
,
Care and treatment
2022
Background
Poor-grade aneurysmal subarachnoid hemorrhage (SAH) is associated with poor neurological outcome and high mortality. A major factor influencing morbidity and mortality is brain swelling in the acute phase. Decompressive craniectomy (DC) is currently used as an option in order to reduce intractably elevated intracranial pressure (ICP). However, execution and optimal timing of DC remain unclear.
Methods
PICASSO resembles a multicentric, prospective, 1:1 randomized standard treatment-controlled trial which analyzes whether primary DC (pDC) performed within 24 h combined with the best medical treatment in patients with poor-grade SAH reduces mortality and severe disability in comparison to best medical treatment alone and secondary craniectomy as ultima ratio therapy for elevated ICP. Consecutive patients presenting with poor-grade SAH, defined as grade 4–5 according to the World Federation of Neurosurgical Societies (WFNS), will be screened for eligibility. Two hundred sixteen patients will be randomized to receive either pDC additional to best medical treatment or best medical treatment alone. The primary outcome is the clinical outcome according to the modified Rankin Scale (mRS) at 12 months, which is dichotomized to favorable (mRS 0–4) and unfavorable (mRS 5–6). Secondary outcomes include morbidity and mortality, time to death, length of intensive care unit (ICU) stay and hospital stay, quality of life, rate of secondary DC due to intractably elevated ICP, effect of size of DC on outcome, use of duraplasty, and complications of DC.
Discussion
This multicenter trial aims to generate the first confirmatory data in a controlled randomized fashion that pDC improves the outcome in a clinically relevant endpoint in poor-grade SAH patients.
Trial registration
DRKS DRKS00017650. Registered on 09 June 2019.
Journal Article
RIG-I Detects Triphosphorylated RNA of Listeria monocytogenes during Infection in Non-Immune Cells
by
Jakobs, Christopher
,
Schlee, Martin
,
Higgins, Paul G.
in
Adaptor Proteins, Signal Transducing - antagonists & inhibitors
,
Adaptor Proteins, Signal Transducing - genetics
,
Adaptor Proteins, Signal Transducing - metabolism
2013
The innate immune system senses pathogens by pattern recognition receptors in different cell compartments. In the endosome, bacteria are generally recognized by TLRs; facultative intracellular bacteria such as Listeria, however, can escape the endosome. Once in the cytosol, they become accessible to cytosolic pattern recognition receptors, which recognize components of the bacterial cell wall, metabolites or bacterial nucleic acids and initiate an immune response in the host cell. Current knowledge has been focused on the type I IFN response to Listeria DNA or Listeria-derived second messenger c-di-AMP via the signaling adaptor STING. Our study focused on the recognition of Listeria RNA in the cytosol. With the aid of a novel labeling technique, we have been able to visualize immediate cytosolic delivery of Listeria RNA upon infection. Infection with Listeria as well as transfection of bacterial RNA induced a type-I-IFN response in human monocytes, epithelial cells or hepatocytes. However, in contrast to monocytes, the type-I-IFN response of epithelial cells and hepatocytes was not triggered by bacterial DNA, indicating a STING-independent Listeria recognition pathway. RIG-I and MAVS knock-down resulted in abolishment of the IFN response in epithelial cells, but the IFN response in monocytic cells remained unaffected. By contrast, knockdown of STING in monocytic cells reduced cytosolic Listeria-mediated type-I-IFN induction. Our results show that detection of Listeria RNA by RIG-I represents a non-redundant cytosolic immunorecognition pathway in non-immune cells lacking a functional STING dependent signaling pathway.
Journal Article
Human TLR8 Senses RNA From Plasmodium falciparum-Infected Red Blood Cells Which Is Uniquely Required for the IFN-γ Response in NK Cells
2019
During blood-stage malaria, the innate immune system initiates the production of pro-inflammatory cytokines, including IFN-γ, that are critical to host defense and responsible for severe disease. Nonetheless, the innate immune pathways activated during this process in human malaria remain poorly understood. Here, we identify TLR8 as an essential sensor of
-infected red blood cells (iRBC). In human immune cells, iRBC and RNA purified from iRBC were detected by TLR8 but not TLR7 leading to IFN-γ induction in NK cells. While TLR7 and 9 have been shown to lead to IFN-γ in mice, our data demonstrate that TLR8 was the only TLR capable of inducing IFN-γ release in human immune cells. This unique capacity was mediated by the release of IL-12p70 and bioactive IL-18 from monocytes, the latter via a hitherto undescribed pathway. Altogether, our data are the first reported activation of TLR8 by protozoan RNA and demonstrate both the critical role of TLR8 in human blood-stage malaria and its unique functionality in the human immune system. Moreover, our study offers important evidence that mouse models alone may not be sufficient to describe the human innate immune response to malaria.
Journal Article