Novel NKG2D-directed bispecific antibodies enhance antibody-mediated killing of malignant B cells by NK cells and T cells

The activating receptor natural killer group 2, member D (NKG2D) represents an attractive target for immunotherapy as it exerts a crucial role in cancer immunosurveillance by regulating the activity of cytotoxic lymphocytes. In this study, a panel of novel NKG2D-specific single-chain fragments variable (scFv) were isolated from naïve human antibody gene libraries and fused to the fragment antigen binding (Fab) of rituximab to obtain [CD20×NKG2D] bibodies with the aim to recruit cytotoxic lymphocytes to lymphoma cells. All bispecific antibodies bound both antigens simultaneously. Two bibody constructs, [CD20×NKG2D#3] and [CD20×NKG2D#32], efficiently activated natural killer (NK) cells in co-cultures with CD20+ lymphoma cells. Both bibodies triggered NK cell-mediated lysis of lymphoma cells and especially enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) by CD38 or CD19 specific monoclonal antibodies suggesting a synergistic effect between NKG2D and FcγRIIIA signaling pathways in NK cell activation. The [CD20×NKG2D] bibodies were not effective in redirecting CD8+ T cells as single agents, but enhanced cytotoxicity when combined with a bispecific [CD19×CD3] T cell engager, indicating that NKG2D signaling also supports CD3-mediated T cell activation. In conclusion, engagement of NKG2D with bispecific antibodies is attractive to directly activate cytotoxic lymphocytes or to support their activation by monoclonal antibodies or bispecific T cell engagers. As a perspective, co-targeting of two tumor antigens may allow fine-tuning of antibody cancer therapies. Our proposed combinatorial approach is potentially applicable for many existing immunotherapies but further testing in different preclinical models is necessary to explore the full potential.

Antibody bivalency improves antiviral efficacy by inhibiting virion release independently of Fc gamma receptors

Across the animal kingdom, multivalency discriminates antibodies from all other immunoglobulin superfamily members. The evolutionary forces conserving multivalency above other structural hallmarks of antibodies remain, however, incompletely defined. Here, we engineer monovalent either Fc-competent or -deficient antibody formats to investigate mechanisms of protection of neutralizing antibodies (nAbs) and non-neutralizing antibodies (nnAbs) in virus-infected mice. Antibody bivalency enables the tethering of virions to the infected cell surface, inhibits the release of virions in cell culture, and suppresses viral loads in vivo independently of Fc gamma receptor (FcγR) interactions. In return, monovalent antibody formats either do not inhibit virion release and fail to protect in vivo or their protective efficacy is largely FcγR dependent. Protection in mice correlates with virus-release-inhibiting activity of nAb and nnAb rather than with their neutralizing capacity. These observations provide mechanistic insights into the evolutionary conservation of antibody bivalency and help refining correlates of nnAb protection for vaccine development.

Pan-tropical Sentinel-2 cloud-free annual composite datasets

Sentinel-2 MSI is one of the core missions of the Copernicus Earth Observation programme of the European Union. This mission shows great potential to map the regional high-resolution spatio-temporal dynamics of land use and land cover. In tropical regions, despite the high revisiting time of 5 days including both Sentinel-2A and 2B satellites, the frequent presence of clouds, cloud-shadows, haze and other atmospheric contaminants are precluding the visibility of the Earth surface up to several months. In this paper we present four annual pan-tropical cloud-free composites computed and exported from Google Earth Engine (GEE) by making use of available Sentinel-2 L1C collection for the period spanning from 2015 to 2020. We furthermore propose empirical approaches to reduce the BRDF effect over tropical forest areas by showing pros and cons of image-based versus swath-based methodologies. Additionally, we provide a dedicated web-platform offering a fast and intuitive way to browse and explore the proposed annual composites as well as layers of potential annual changes as a ready-to-use means to visually identify and verify degradation and deforestation activities as well as other land cover changes.

Patients with acute myocardial infarction and severe target lesion calcifications undergoing percutaneous coronary intervention have poor long-term prognosis

BACKGROUND

To assess the influence of severe target lesion calcification (TLC) on the outcomes of patients undergoing percutaneous coronary interventions (PCI) due to acute myocardial infarction (AMI).

AIM

Contemporary data concerning coronary artery calcifications (CAC) are based on pooled analyses from randomised trials with short follow-up. We still lack the knowledge on how CAC in target lesions affect long-term prognosis of patients with AMI in everyday practice.

METHODS

We evaluated clinical and laboratory data of 206 consecutive patients who underwent coronary angiography and PCI due to AMI. Primary endpoints were all-cause death and recurrent hospitalisations due to acute coronary syndrome (ACS).

RESULTS

Severe TLC lesions were present in 17% of patients. These patients were older (71 vs. 65 years, p = 0.02) and more often diagnosed with non-ST segment elevation myocardial infarction (77% vs. 58%, p = 0.03). Patients with severe TLC had lower rates of PCI success (80% vs. 97%, p < 0.0001) and less often achieved full revascularisation during index procedure (14% vs. 41%, p = 0.003). During 30 months follow-up patients with severe TLC more often suffered from another ACS (37% vs. 13%, p = 0.0005) and had higher all-cause mortality (31% vs. 16%, p = 0.04). Multivariate Cox regression model showed severe TLC to be an independent predictor of another ACS (HR 2.8; 95% CI 1.4-5.6; p = 0.004).

CONCLUSIONS

Severe TLC are not uncommon in patients with ACS. The presence of severe TLC is a prognostic factor of another ACS in AMI patients undergoing PCI.

Superexchange-mediated ferromagnetic coupling in two-dimensional Ni-TCNQ networks on metal surfaces

We investigate the magnetic coupling of Ni centers embedded in two-dimensional metal-coordination networks self-assembled from 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules on Ag(100) and Au(111) surfaces. X-ray magnetic circular dichroism measurements show that single Ni adatom impurities assume a spin-quenched configuration on both surfaces, while Ni atoms coordinating to TCNQ ligands recover their magnetic moment and exhibit ferromagnetic coupling. The valence state and the ferromagnetic coupling strength of the Ni coordination centers depend crucially on the underlying substrate due to the different charge state of the TCNQ ligands on the two surfaces. The results suggest a superexchange coupling mechanism via the TCNQ ligands.

Fabrication of quasiperiodic nanostructures with EUV interference lithography

We demonstrate the fabrication and analysis of well-ordered high-resolution quasiperiodic nanostructures with feature sizes down to a few tens of nanometers using extreme ultraviolet interference lithography. A well-controlled mask manufacturing process for producing high quality transmission diffraction masks enables simple and fast fabrication of highly ordered 2D quasiperiodic structures using 5- and 8-beam interference setups.

Concentric Metallic-Piezoelectric Microtube Arrays

Trilayer concentric metallic-piezoelectric-metallic microtubes are fabricated by infiltrating porous Si templates with sol precursors. LaNiO3 (LNO) is used as the inner and outer electrode material and PbZrTiO3 (PZT) is the middle piezoelectric layer. Structure of the microtubes is characterized in details using scanning and transmission electron microscopy which are equipped with energy dispersive X-ray spectroscopy for elemental mapping. The hysteresis of a trilayered thin film structure of LNO-PZT-LNO is shown. This trilayered tubes might find applications in inkjet printing.

Picosecond time resolved photoluminescence spectroscopy of a tetracene film on highly oriented pyrolytic graphite: Dynamical relaxation, trap emission, and superradiance

A detailed time resolved investigation of the photoluminescence of a thin tetracene film deposited on highly oriented pyrolytic graphite is presented. In agreement with Lim et al. [Phys. Rev. Lett. 92, 107402 (2004)], we find strong evidence for superradiance: an increase of the relative intensity of the pure electronic transition with respect to the vibronic sideband and a concomitant decrease of the radiative lifetime from 10 to 1.83 ns upon cooling from 300 to 4 K. For lower temperatures, a redshift (approximately 200 cm(-1)) of the free exciton is observed. Previously, this shift was attributed to a structural phase transition. Our time resolved spectra reveal that the spectral shift is related to a dynamical relaxation process which occurs within the first 50 ps.

A randomized, single-blind comparison of topical clindamycin + benzoyl peroxide (Duac) and erythromycin + zinc acetate (Zineryt) in the treatment of mild to moderate facial acne vulgaris

BACKGROUND

Antibiotics are often combined with other agents to provide topical acne treatments that are effective against both inflammatory and non-inflammatory lesions and minimize the development of antibiotic resistance.

OBJECTIVES

To compare the clinical effectiveness of two combination treatments for facial acne: a ready mixed, once daily gel containing clindamycin phosphate (1%) plus benzoyl peroxide (5%) (CDP + BPO) and a twice daily solution of erythromycin (4%) plus zinc acetate (1.2%) (ERY + Zn).

METHODS/PATIENTS

In this assessor-blind, randomized study, 73 patients were treated with CDP + BPO once daily and 75 patients with ERY + Zn twice daily. The treatment period was 12 weeks and lesion counts and global improvement were assessed at weeks 1, 2, 4, 8 and 12.

RESULTS

CDP + BPO showed an earlier onset of action with a faster significant reduction in total lesion counts than ERY + Zn. The proportion of patients with at least a 30% improvement in non-inflammatory lesions at week 1 was 31.5% for CDP + BPO and 17.3% for ERY + Zn; the corresponding percentages for inflammatory lesions were 39.7% and 29.3%. A difference was also observed at week 2 (53.4% vs. 36.0% for non-inflammatory lesions and 72.6% vs. 53.3% for inflammatory lesions). The trend in favour of CDP + BPO, although less marked, continued to the end of the study, with reductions in the total lesion count at endpoint of 69.8% for CDP + BPO group and 64.5% for ERY + Zn group. Both treatments were well tolerated.

CONCLUSIONS

CDP + BPO and ERY + Zn are effective treatments for acne but CDP + BPO has an earlier onset of action that should improve patient compliance.

Biophysical and biochemical properties of a binary lipid mixture for DNA transfection

The phase and miscibility behavior of a triple-chain phosphatidylcholine (TPHPC) and a single-chain surfactant (CTAB) were investigated in aqueous dispersions and in monolayers at the air/water interface. CTAB can be incorporated in the TPHPC monolayer because of its complementary molecule shape and reduces the tilt angle of TPHPC. The type of phases and the phase sequence (L2 - LS) are the same in the pure TPHPC monolayer and in the TPHPC/CTAB (80:20 mol:mol) mixture. No indication of any ordering of adsorbed DNA was observed. In the aqueous dispersions, TPHPC exhibits an inverted hexagonal phase above the chain melting. The addition of 30 mol% CTAB leads to the appearance of a lamellar Lalpha phase. The binding of DNA to the mixture is obvious but this is accompanied by a separation of the two lipids what is supported by monolayer experiments. The system has no long-term stability. The main reason seems to be not only the stronger interaction of DNA with CTAB, but also especially the unexpected weak interaction between CTAB and TPHPC. The transfection efficiency is lower compared with lipofectamine. The main disadvantage of this system is the cytotoxicity of CTAB, which could not be lowered by incorporation of CTAB in the TPHPC bilayer.

Long-term safety of topical calcitriol 3 microg g(-1) ointment

To assess the topical and systemic safety and tolerance of twice-daily application of 3 microg g(-1) 1alpha25-dihydroxyvitamin D3 (calcitriol) ointment (Silkis ointment, Galderma Laboratories) in the long-term treatment of patients suffering from chronic plaque psoriasis, we performed an open-design, multicentre study. Two hundred and fifty-three patients (155 males, 98 females) treated all their psoriatic lesions, except for those on the head and scalp, for up to 78 weeks. No serious adverse events were reported: 37 patients (14.6%) had a transient skin irritation reaction on one or more occasions during the study that resulted in study withdrawal for seven of them. The baseline/endpoint analyses showed no clinically relevant changes in measures of calcium and phosphorus homeostasis and renal function. Slight hypercalcaemia was observed in five (2%) patients: in four of these patients, serum albumin-adjusted total calcium levels normalized during treatment. In conclusion, twice-daily calcitriol 3 microg g(-1) ointment is safe and well tolerated in the long-term treatment of chronic plaque psoriasis.

Cytochrome P450 1A1 and 4A activities in isolated rat spleen lymphocytes

In this study the activity of Cytochrome P 450 (CYP) enzymes in isolated spleen lymphocytes of Wistar rats was estimated. 7-Ethoxyresorufin-O-deethylase was analysed to determine the activity of CYP 1A1/2. The activity was increased 2.2-fold by pretreating the animals with 3-methylcholanthrene, and 1.3-fold after the addition of the mitogen concanavalin A to the lymphocyte culture. Pretreatment of the rats with phenobarbitone did not enhance the basal enzyme activity. To estimate reductive activities the azoreduction of 4-(N,N-dimethyl-amino)azobenzene was analysed. Again detectable turnovers were found which could be increased 4-fold after the addition of concanavalin A. Azo-reductase activity could also be increased 2-fold after clofibrate was added to the lymphocyte cultures, and was decreased by adding metyrapone so that it was concluded that azoreduction may be partly due to the CYP 4A-family.

Efficacy and tolerance of topical calcitriol 3 microg g(-1) in psoriasis treatment: a review of our experience in Poland

Although topical vitamin D3 derivatives have been used in the treatment of patients with psoriasis for the past 15 years, questions remain about the indications and limitations of application. Extensive personal experience gained during the development of calcitriol (1alpha25-dihydroxyvitamin D3) is therefore reviewed. Three double-blind, vehicle-controlled trials have revealed that calcitriol 3 microg g(-1) ointment (Silkis ointment, Galderma Laboratories) has very good clinical efficacy. In a left-right comparison with vehicle ointment, complete clearance of psoriatic lesions was achieved in 48% of sites treated with calcitriol and a further 41% showed considerable or definite improvement. The clinical response to calcitriol in another study was as good as, or even better than, that achieved with betamethasone valerate 0.1% ointment. A preparation containing calcitriol 15 microg g(-1) did not show any clinical superiority to the lower dose but was associated with a higher risk of hypercalciuria, particularly when applied to extensive skin lesions. These results suggest that calcitriol 3 microg g(-1) ointment is an effective and safe treatment for chronic plaque psoriasis.

Bioanalysis of syn dimeric HIV-1 protease inhibitor N-benzyl 4-aryl-1,4-dihydropyridine H19: metabolic and cytotoxic properties in Hep G2 cells

Syn dimeric N-benzyl 4-aryl-1,4-dihydropyridine H19 is a nonpeptidic HIV-1 protease inhibitor of the dihydroxyethylene type representing novel C2-symmetric inhibitors. Great interest was focussed on the extent of metabolism of these novel inhibitory structures as their functional groups are similar to certain peptidic and non-peptidic HIV-1 protease inhibitors with poor bioavailability due to extensive metabolism. Thus, early characterization of metabolic and toxic properties decisively determines the future prospects of those novel HIV-1 protease inhibitors. Both metabolism and toxicity were evaluated in Hep G2 monolayers. While no phase-I metabolites were found the extent of conjugation in phase-II of biotransformation was poor. Moreover, cytotoxic evaluation of protein and DNA decrease and, furthermore, of membrane toxicity characterized the novel inhibitors as non-toxic. Consequently, the favourable poor metabolism and non-toxic properties encourage further development of these novel HIV-1 protease inhibitors.

First bioanalytical evaluation of nonpeptidic cage dimeric HIV-1 protease inhibitor N-benzyl 4-aryl-1,4-dihydropyridine H17: biotransformation and toxicity on Hep G2 cells

Cage dimeric N-benzyl 4-aryl-1,4-dihydropyridine H17 is a moderate inhibitor of HIV-1 protease. As representative of an innovative and promising class of nonpeptidic HIV-1 protease inhibitors H17 was selected for the characterization of the biochemical profile of the cage dimers concerning metabolic and toxic aspects. In the first bioanalytical evaluation of H17 on Hep G2 monolayers no phase-I metabolites were found and the extent of conjugation on phase-II of biotransformation was poor due to steric hindrance of the hydroxymethylene groups. H17 was found to be nearly non-toxic. A slight noticeable influence on cell proliferation, however, did not result from apoptotic activities. Thus, first biochemical evaluation of H17 practically suggests no decrease of an in-vivo bioavailability by metabolization.

Nitroxide metabolism in the human keratinocyte cell line HaCaT

Metabolism of different nitroxides with piperidine structure used as spin labels in electron spin resonance (ESR) studies in vitro and in vivo was investigated in human keratinocytes of the cell line HaCaT by GC and GC-MS technique combined with S-band ESR. Besides the well known reduction of the nitroxyl radicals to the ESR silent hydroxylamines as primary products our results indicate the formation of the corresponding secondary amines. These reductions are inhibited by the thiol blocking agent N-ethylmaleimide and by the strong inhibitors of the thioredoxin reductase (TR) 2-chloro-2,4-nitrobenzene and 2,6-dichloroindophenol. The competitive inhibitor TR inhibitor azelaic acid and the cytochrome P-450 inhibitor metyrapone lack any effects. The rates of reduction to the hydroxylamines and secondary amines were dependent on the lipid solubility of the nitroxides. Therefore, it can be assumed that the nitroxides must enter the cells for their bioreduction. The mostly discussed intracellular nitroxide reducing substances ascorbic acid and glutathione were unable to form the secondary amines. In conclusion, our results suggest that the secondary amine represents one of the major metabolites of nitroxides besides the hydroxylamine inside keratinocytes formed via the flavoenzyme thioredoxin reductase most probably. Further metabolic conversions were detected with 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl and the benzoate of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl as substrates.

Biotransformation and toxicity of the lipoxygenase inhibitor 2-hydroxy-5-methyllaurophenone oxime (FLM 5011) on Hep G2 cells

2-Hydroxy-5-methyllaurophenone oxime (FLM 5011) is an inhibitor of lipoxygenase with antiinflammatory and antiallergic actions. We incubated FLM 5011 on the human immortal cell line Hep G2 and found a similar metabolite spectrum as in rat urine and faeces. We also measured the cytotoxicity of FLM 5011 on Hep G2 monolayers by the amido black assay and found that the influence of cell proliferation is partly due to apoptotic activities. Although the metabolic activity of Hep G2 cells is lower compared to rat hepatocyte cultures they are a suitable test system for biotransformation studies. Their higher proliferation rate allows toxicity to be characterised more exactly.

A long-term multicentre assessment of the safety and tolerability of calcitriol ointment in the treatment of chronic plaque psoriasis

Calcitriol (1 alpha,25-dihydroxyvitamin D3), applied topically in an ointment base, has been shown to be effective in the treatment of chronic plaque psoriasis. This open study was designed to assess the safety and tolerability of 3 micrograms/g calcitriol ointment applied twice daily over treatment periods of up to 78 weeks. In the 253 evaluable patients with chronic plaque psoriasis no clinically relevant changes were observed in the baseline/end-point analyses of mean serum levels of total calcium, albumin-adjusted total calcium, phosphorus and creatinine, and plasma calcitriol levels. Mean values of 24-h urinary calcium, phosphorus, creatinine and hydroxyproline excretions, creatinine clearance and mean urinary calcium/creatinine ratio also did not show clinically relevant changes in the baseline/end-point analyses. The treatment was well tolerated, with no serious adverse events occurring during the course of the study. Eight patients withdrew from the study due to adverse events which, although not serious, were thought to be treatment-related: in seven patients skin irritation reactions and in one case a transient asymptomatic slight hypercalcaemia was observed. In addition, assessments of global severity, global improvement and Psoriasis Area and Severity Index scores confirmed the therapeutic efficacy of twice daily 3 micrograms/g calcitriol ointment demonstrated in an earlier controlled study. In conclusion, this study demonstrated that twice daily application of 3 micrograms/g calcitriol ointment is safe and well-tolerated in the treatment of chronic plaque psoriasis.

[Biotransformation of the lipoxygenase inhibitor 2-hydroxy-5-methyl-laurophenone-oxime (FLM 5011)]

2-Hydroxy-5-methyl-laurophenone-oxime (FLM 5011, 1) is an inhibitor of the lipoxygenase with antiinflammatory and antiallergic actions. The studies on the biotransformation using in vivo investigations and in vitro test systems resulted in finding of at least eight metabolites. Four of these compounds have been detected and identified in urine and faeces after p.o. administration in male Wistar rats. By means of cultures of hepatocytes, lymphocytes and myeloma cells additional metabolites were found and the main pathways of metabolism could be suggested. Furthermore it was possible to confirm the sequence of the metabolic reactions. First of all, 1 is hydroxylated in the omega-position of the lauryl side chain by the cytochrome P-450 system. The further oxidation to the carboxylated compound is followed by the stepwise degradation of the side chain by beta-oxidation similarly to the pathways of fatty acid metabolism. Simultaneously the oxime group is converted to the keto group. The metabolites and 1 partly occur as sulfate or glucuronide conjugates. Additionally all compounds produced by beta-oxidation are conjugated with other partners, probably amino acids. By omega-oxidation, compounds with higher inhibitory potency on the lipoxygenase than the parent compound are formed. These results suggest that the activity of 1 is partly caused by the initial metabolites.

[The use of lymphocyte cultures for the investigation of drug biotransformation]

In the present paper the rat lymphocytes and mouse myeloma cell culture are developed as in vitro test systems and used for the investigation on the biotransformation of drugs. The rat lymphocyte culture was established as a suspension culture after the isolation of the cells from the spleen of male wistar rats by mechanical disaggregation and density gradient centrifugation with a yield of 10(7) cells per spleen and a viability of 80%. The addition of the mitogens PHA and Con A to the culture stimulated the proliferation of the lymphocytes leading to a doubling of the number of cells comparing with control cultures. Myeloma cells are a permanent cell line of B-lymphocytes. The cultivation was carried out as stationary suspension. The marked proliferation of the cells could be increased by addition of Con A. The biochemical properties of both kinds of cells are qualitatively comparable. Cytochrome P-450 mediated demethylase activities could be detected, which were 5-10 fold higher in myeloma cells. The pretreatment with the enzyme inductors phenobarbitone and 3-methylcholanthrene as well as the addition of the mitogens PHA and Con A increased these turnover rates. Reductive and conjugating activities were not present in the cultures. The established and characterized in vitro systems were applied for the investigation on the biotransformation of 4 potential drugs. The cardiac effective Trapidil (Rocornal) derivative AR 12463 (5-piperidino-7-[N-pentyl-N-(beta-hydroxyethyl)]- amino-s-triazolo[1,5-a]pyrimidine) is transformed in lymphocyte and myeloma cell cultures in two compounds. These substances revealed as the hydroxypentyl- and the hydroxypyrimidine derivative.(ABSTRACT TRUNCATED AT 250 WORDS)

[The biotransformation of the immunostimulant 3-(2-mercaptoethyl)quinazoline-2,4(1H,3H)-dione (AWD 100-041)]

3-(2-Mercaptoethyl)quinazoline-2,4(1 H,3 H)-dione (1; AWD 100-041) is a substance with immunomodulating and immunorestorative activity. After p.o. administration in male Wistar rats at least 7 metabolites are formed and excreted in urine and faeces. The compounds were isolated and identified on the basis of UV and mass spectra. They are S-methylated structures in which sulfoxidation and ring-hydroxylation have been taken place. Four metabolites are also present as sulfate or glucuronide conjugates. The quantity ratio of the phase I to phase II metabolites amounts to 4:1. In the isolated perfused rat liver and rat hepatocyte culture 6 and 5 of the in vivo identified compounds are formed. The sequence of the metabolic pathways could be confirmed by in vitro experiments in which the incubation of synthetically prepared metabolites and the identification of generated biotransformation products were performed. In the lymphocyte and myeloma cell culture solely the disulfide of 1 is formed. After incubation of the S-methyl compound metabolites originate detectable also in vivo. Regarding the main ways of metabolism firstly 1 is attacked by methyltransferases forming the initial metabolite. After that oxidative processes take place leading to the formation of sulfoxides, sulfones as well as ring-hydroxylated compounds. A part of the ring-hydroxylated metabolites are conjugated.