Outcome of COVID-19 in Patients With Mantle Cell Lymphoma-Report From the European MCL Registry

Data on outcome of patients with mantle cell lymphoma (MCL) and COVID-19 infection are limited. The European MCL (EMCL) registry is a centralized registry of the EMCL network, collecting real-world information about treatments and disease courses. During the COVID-19 pandemic, additional data on MCL patients with COVID-19 infection were collected, aiming to identify risk factors for mortality from COVID-19. In our retrospective, multicenter, international study, we collected data from 63 MCL patients with a median age of 64 years (range, 44–84) in 9 countries with evidence of a COVID-19 infection between February 2020 and October 2021. The overall mortality rate was high (44.4%), especially in hospitalized patients (61%) and in patients with need for intensive care unit care (94%). Patients receiving rituximab had significantly poorer survival than patients not receiving rituximab (P = 0.04). Our data highlight the importance of prevention strategies and underline the need for effective vaccination in this vulnerable cohort

Aktivität der humanen Meprin-Metalloproteasen unter Berücksichtigung potentieller Aktivatoren

Die Metalloproteasen Meprin α und Meprin β sind an essentiellen (patho)physiologischen Prozessen beteiligt. Um die Funktion dieser Proteasen zu verstehen, ist es von Bedeutung, sie nicht isoliert, sondern im gesamten proteolytischen Netzwerk zu betrachten.rnDie Meprine werden in einer Vielzahl von Geweben, in Leukozyten, aber auch in Krebszellen exprimiert. In der Haut konnten die beiden Enzyme in unterschiedlichen dermalen Schichten detektiert werden, wo sie u.a. an der Kollagenassemblierung durch Abspaltung der Propeptide beteiligt sind. rnIm Zuge von Proteomics Analysen konnten mehr als 3000 proteolytische Schnittstellen von fünf Astacin-Metalloproteasen (Meprin α, Meprin β, Astacin, LAST und LAST_MAM) in Peptiden und nativen Substraten identifiziert werden und somit eine Aussage über die Spaltspezifität getroffen werden. In der vorliegenden Arbeit konnten diese Spaltspezifitäten mit Hilfe von fluorogenen Substraten in vitro verifiziert werden. Bemerkenswert hierbei ist die starke Präferenz der beiden Meprine und LAST_MAM für die Aminosäuren Aspartat und Glutamat in der P1‘ Position. rnMeprine werden als Zymogene exprimiert und müssen durch proteolytische Prozessierung einer tryptischen Protease aktiviert werden. Ein Schwerpunkt der vorliegenden Arbeit waren Aktivitätsbestimmungen beider Meprine unter Berücksichtigung potentieller Aktivatoren und Substrate. Es konnten die kallikrein-related peptidases (KLK) 4, 5 und 8 als spezifische Aktivatoren identifiziert werden, wobei nur KLK5 beide Proteasen aktiviert. Sowohl KLK4 als auch KLK8 sind lediglich in der Lage, das Propeptid von Meprin β abzuspalten. Außerdem konnte biochemisch und mittels Proteomics gezeigt werden, dass proKLK7 von Meprin β prozessiert wird. Durch N-terminale Sequenzierung wurde eine Schnittstelle zwei Aminosäuren N-terminal der eigentlichen Aktivierungsstelle identifiziert. Dieser Schritt beschleunigt die Aktivierung von KLK7, wenn durch Trypsin noch das verbliebene Dipeptid abgespalten wird. rnDa einige Vertreter der humanen kallikrein-related peptidases (KLK) als Meprin-Aktivatoren identifiziert werden konnten, sollten diese im Zuge dieser Arbeit im Modellorganismus Danio rerio untersucht werden. Durch in silico und RT-PCR Analysen konnte gezeigt werden, dass keine funktionellen KLK-Homologe im Zebrafisch codiert sind. Da somit andere tryptische Proteasen an der Aktivierung der Meprine beteiligt sein müssen, wurde die Transmembran-Serinprotease TMPRSS4 analysiert. In der Tat zeigte die Reduktion des Expressionslevels von TMPRSS4 durch Morpholino-Injektion drastische Störungen in der embryonalen Entwicklung von Zebrabärblingen. Mittels Licht- und Rasterelektronenmikroskopie ließ sich eine Fehlbildung der epidermalen Haut bis zu einem Ablösen der Keratinozyten von dem darunter liegenden Gewebe feststellen. rnThe metalloproteases Meprin α and Meprin β are essential players in (patho)physiological processes. To understand their function in health and disease, it is crucial to study not only the individual proteases but also their relations within the entire proteolytic web. rnMeprins are expresses in several tissues, leucocytes and a variety of cancer cells. In skin, they are located in separate layers of human epidermis, and in dermal fibroblasts, being involved in collagen assembly by propeptide cleavage.rnUsing degradomics approaches more than 3,000 cleavage sites were proteomically identified for five astacin metalloproteases (Meprin α, Meprin β, Astacin, LAST und LAST_MAM), revealing their cleavage specificities. In this work, we were able to validate these cleavage specificities using fluorogenic peptide substrates. Remarkably, Meprin α, Meprin β and LAST_MAM proteases exhibit a strong preference for aspartate and glutamate in the P1’ position, unique amongst all extracellular proteases.rnMeprins are secreted as zymogens that are activated by tryptic proteolytical processing. Here we identified human kallikrein-related peptidases (KLKs) 4, 5 and 8 to be specific activators of Meprins. KLK5 is capable of activating both metalloproteases. Interestingly, KLK4 and 8 cleave off the propeptide of meprin β only. Moreover, biochemical analysis and proteomics tools show that proKLK7 is processed by meprin β. N-terminal sequencing revealed cleavage two amino acids N-terminal to mature KLK7. Interestingly, this triggering led to an accelerated activation of the serine protease in the presence of trypsin. rnSince human KLKs could be identified as potential activators for meprins our aim was to investigate meprin activation in the suitable model organism Danio rerio. However, in situ and RT-PCR analysis revealed no functional KLK homologues in zebrafish. Hence, other tryptic proteases must be involved in meprin activation, and therefore we analysed the transmembrane serine protease TMPRSS4. Indeed, the in vivo gene silencing by morpholino injection caused severe defects of zebrafish embryonic development. Using light microscopy and scanning electron microscopy a disturbed epidermal skin organization, with clearly altered cell-cell-contacts, resulting in the detachment of keratinocytes from the underneath tissue, could be observed. r

Cure rate in the elderly patients with diffuse large B cell lymphoma deteriorates after the age of 80—results from a single-center survey

The prognosis of elderly patients diagnosed with diffuse large B cell lymphoma (DLBCL) is considered to be clearly inferior to that of younger patients. Besides tumor biology and comorbidities, treatment selection due to an assumed reduced tolerability may contribute to this difference. With increasingly more patients diagnosed at advanced age, current treatment selections need to be reviewed carefully. Hence, we analyzed the results of patients above the age of 70 in whom a diagnosis of DLBCL was made. Whereas patients up to 80 were frequently selected for and were able to tolerate standard treatment (86% intended use, 74% completion), patients above the age of 80 years were not only treated more cautiously (67 and 60%, respectively) but did show inferior response to treatment with standard treatment (CR rate for intended R-CHOP use 64% vs. 43%). However, on an individual level, patients receiving and completing standard treatment obtained results that resemble the results of younger patients, irrespective if aged more than 80 and impose superior to prior reports in this age cohort. Median PFS for the entire group of patients was 3.44 years, with 4.83 years for patients below 80 and only 1.09 years for patients above the age of 80. The corresponding figures for OS were 7.38 years (estimated); after 2 years, OS was 81% in the younger cohort in contrast to 68% in patients > 80 years. However, for patients not planned to receive or not tolerating R-CHOP, results remain poor; tailored approaches for these patients are required

The substrate degradome of meprin metalloproteases reveals an unexpected proteolytic link between meprin β and ADAM10.

The in vivo roles of meprin metalloproteases in pathophysiological conditions remain elusive. Substrates define protease roles. Therefore, to identify natural substrates for human meprin α and β we employed TAILS (terminal amine isotopic labeling of substrates), a proteomics approach that enriches for N-terminal peptides of proteins and cleavage fragments. Of the 151 new extracellular substrates we identified, it was notable that ADAM10 (a disintegrin and metalloprotease domain-containing protein 10)-the constitutive α-secretase-is activated by meprin β through cleavage of the propeptide. To validate this cleavage event, we expressed recombinant proADAM10 and after preincubation with meprin β, this resulted in significantly elevated ADAM10 activity. Cellular expression in murine primary fibroblasts confirmed activation. Other novel substrates including extracellular matrix proteins, growth factors and inhibitors were validated by western analyses and enzyme activity assays with Edman sequencing confirming the exact cleavage sites identified by TAILS. Cleavages in vivo were confirmed by comparing wild-type and meprin(-/-) mice. Our finding of cystatin C, elafin and fetuin-A as substrates and natural inhibitors for meprins reveal new mechanisms in the regulation of protease activity important for understanding pathophysiological processes

Structure of Molybdenum Oxide Supported on Silica SBA-15 Studied by Raman, UV-Vis and X-Ray Absorption Spectroscopy

The structure of molybdenum oxide supported by silica SBA-15 has been studied by visible Raman spectroscopy, diffuse reflectance UV–Vis spectroscopy and X-ray absorption spectroscopy in the dehydrated state obtained after thermal treatment at elevated temperatures (≥350 °C). No dependence of the molybdenum oxide structure on preparation procedure or loading has been observed within the range of loadings studied in detail (0.2–0.8 Mo/nm2). X-ray absorption spectroscopy (XAS) reveals that the dehydrated state consists of a mixture of monomeric and connected molybdenum oxide centres. While the presence of crystalline MoO3 can be excluded by Raman spectroscopy, tetrahedrally and octahedrally coordinated MoO4 and MoO6 units are identified by XAS. The MoO6 units possess connectivity similar to that of MoO3 building blocks, whereas the MoO4 units are isolated or connected to other MoxOy units. These results are supported by UV–Vis spectra showing intensity at wavelengths (>300 nm) typical for dimeric and/or oligomeric species

The substrate degradome of meprin metalloproteases reveals an unexpected proteolytic link between meprin beta and adam10

The in vivo roles of meprin metalloproteases in pathophysiological conditions remain elusive. Substrates define protease roles. Therefore, to identify natural substrates for human meprin alpha and beta we employed TAILS (terminal amine isotopic labeling of substrates), a proteomics approach that enriches for N-terminal peptides of proteins and cleavage fragments. Of the 151 new extracellular substrates we identified, it was notable that ADAM10 (a disintegrin and metalloprotease domain-containing protein 10)-the constitutive alpha-secretase-is activated by meprin beta through cleavage of the propeptide. To validate this cleavage event, we expressed recombinant proADAM10 and after preincubation with meprin beta, this resulted in significantly elevated ADAM10 activity. Cellular expression in murine primary fibroblasts confirmed activation. Other novel substrates including extracellular matrix proteins, growth factors and inhibitors were validated by western analyses and enzyme activity assays with Edman sequencing confirming the exact cleavage sites identified by TAILS. Cleavages in vivo were confirmed by comparing wild-type and meprin(-/-) mice. Our finding of cystatin C, elafin and fetuin-A as substrates and natural inhibitors for meprins reveal new mechanisms in the regulation of protease activity important for understanding pathophysiological processes

Indirect treatment comparison of brexucabtagene autoleucel (ZUMA-2) versus standard of care (SCHOLAR-2) in relapsed/refractory mantle cell lymphoma

The SCHOLAR-2 retrospective study highlighted poor overall survival (OS) with standard of care (SOC) regimens among patients with relapsed/refractory (R/R) mantle cell lymphoma (MCL) who failed a covalent Bruton tyrosine kinase inhibitor (BTKi). In the ZUMA-2 single-arm trial, brexucabtagene autoleucel (brexu-cel; autologous anti-CD19 CAR T-cell therapy) demonstrated high rates of durable responses in patients with R/R MCL who had previous BTKi exposure. Here, we compared OS in ZUMA-2 and SCHOLAR-2 using three different methods which adjusted for imbalances in prognostic factors between populations: inverse probability weighting (IPW), regression adjustment (RA), and doubly robust (DR). Brexu-cel was associated with improved OS compared to SOC across all unadjusted and adjusted comparisons. Hazard ratios (95% confidence intervals) were 0.38 (0.23, 0.61) for IPW, 0.45 (0.28, 0.74) for RA, and 0.37 (0.23, 0.59) for DR. These results suggest a substantial survival benefit with brexu-cel versus SOC in patients with R/R MCL after BTKi exposure.</p

Altered and allele-specific open chromatin landscape reveals epigenetic and genetic regulators of innate immunity in COVID-19

SARS-CoV-2 infection causes severe COVID-19 in some patients and mild in others. Dysfunctional innate immune responses have been identified to contribute to COVID-19 severity, but the key regulators are still unknown. Here, we present an integrative single-cell multi-omics analysis of peripheral blood mononuclear cells from hospitalized and convalescent COVID-19 patients. In classical monocytes, we identified genes that were potentially regulated by differential chromatin accessibility. Then, sub-clustering and motif-enrichment analyses reveals disease condition-specific regulation by transcription factors and their targets, including an interaction between (C/EBPs) and a long-noncoding RNA (LUCAT1), which we validated through loss-of-function experiments. Finally, we investigated genetic risk variants that exhibit allele-specific open chromatin (AsoC) in COVID-19 patients and identified a SNP rs6800484-C, which is associated with lower expression of (CCR2) and may contribute to higher viral loads and higher risk of COVID-19 hospitalization. Altogether, our study highlights the diverse genetic and epigenetic regulators that contribute to COVID-19