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mRNA technologies have recently proven clinical efficacy against coronavirus disease 2019 and are among the most promising technologies to address the current pandemic. Here, we show preclinical data for our clinical candidate CVnCoV, a lipid nanoparticle-encapsulated mRNA vaccine that encodes full-length, pre-fusion stabilised severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike protein. In contrast to previously published approaches, CVnCoV is exclusively composed of naturally occurring nucleotides. Immunisation with CVnCoV induced strong humoral responses with high titres of virus-neutralising antibodies and robust T-cell responses. CVnCoV vaccination protected hamsters from challenge with wild-type SARS-CoV-2, demonstrated by the absence of viral replication in the lungs. Hamsters vaccinated with a suboptimal dose of CVnCoV leading to breakthrough viral replication exhibited no evidence of vaccine-enhanced disease. Overall, data presented here provide evidence that CVnCoV represents a potent and safe vaccine candidate against SARS-CoV-2.

Imaging techniques such as positron emission tomography need radionuclides that can be produced with cyclotrons. The involved nuclear reactions mostly produce neutron and gamma radiation, which must be shielded. In order to be able to determine the required thickness of the shielding for a newly bought medical cyclotron, corresponding radiation protection calculations were carried out. The necessary neutron source term was supplied by the manufacturer. To verify this source term, additional source terms were calculated with the MCNP6 and the FLUKA code packages. The results with the source, on base of code internal nuclear models, produced comparable results, but the neutron yield with the source supplied by the manufacturer turned out to be lower by a factor of about 5. To validate the results, experiments were carried out on an already existing cyclotron. Neutron fluence was measured with standard monitors which are used in reactor dosimetry. The experiments were performed during regular 18 F production. Activities of the nuclides were measured by gamma spectroscopy and compared with the calculated activities.

The CVnCoV (CureVac) mRNA vaccine for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was recently evaluated in a phase 2b/3 efficacy trial in humans 1 . CV2CoV is a second-generation mRNA vaccine containing non-modified nucleosides but with optimized non-coding regions and enhanced antigen expression. Here we report the results of a head-to-head comparison of the immunogenicity and protective efficacy of CVnCoV and CV2CoV in non-human primates. We immunized 18 cynomolgus macaques with two doses of 12 μg lipid nanoparticle-formulated CVnCoV or CV2CoV or with sham ( n  = 6 per group). Compared with CVnCoV, CV2CoV induced substantially higher titres of binding and neutralizing antibodies, memory B cell responses and T cell responses as well as more potent neutralizing antibody responses against SARS-CoV-2 variants, including the Delta variant. Moreover, CV2CoV was found to be comparably immunogenic to the BNT162b2 (Pfizer) vaccine in macaques. Although CVnCoV provided partial protection against SARS-CoV-2 challenge, CV2CoV afforded more robust protection with markedly lower viral loads in the upper and lower respiratory tracts. Binding and neutralizing antibody titres were correlated with protective efficacy. These data demonstrate that optimization of non-coding regions can greatly improve the immunogenicity and protective efficacy of a non-modified mRNA SARS-CoV-2 vaccine in non-human primates. CV2CoV, a second-generation mRNA COVID-19 vaccine with non-modified nucleosides but optimized non-coding regions, is demonstrated to be effective against SARS-CoV-2 challenge when tested in non-human primates.

The ongoing SARS-CoV-2 pandemic necessitates the fast development of vaccines. Recently, viral mutants termed variants of concern (VOC) which may escape host immunity have emerged. The efficacy of spike encoding mRNA vaccines (CVnCoV and CV2CoV) against the ancestral strain and the VOC B.1.351 was tested in a K18-hACE2 transgenic mouse model. Naive mice and mice immunized with a formalin-inactivated SARS-CoV-2 preparation were used as controls. mRNA-immunized mice develop elevated SARS-CoV-2 RBD-specific antibody and neutralization titers which are readily detectable, but significantly reduced against VOC B.1.351. The mRNA vaccines fully protect from disease and mortality caused by either viral strain. SARS-CoV-2 remains undetected in swabs, lung, or brain in these groups. Despite lower neutralizing antibody titers compared to the ancestral strain BavPat1, CVnCoV and CV2CoV show complete disease protection against the novel VOC B.1.351 in our studies. Emerging SARS-CoV-2 variants with mutations in the spike protein raise concerns regarding vaccine efficacy. Here, the authors show that two spike encoding mRNA vaccines in preclinical and clinical development protect human ACE2 mice from the B.1.351 variant of concern and ancestral B BavPat1.

Combining optimized spike (S) protein-encoding mRNA vaccines to target multiple SARS-CoV-2 variants could improve control of the COVID-19 pandemic. We compare monovalent and bivalent mRNA vaccines encoding B.1.351 (Beta) and/or B.1.617.2 (Delta) SARS-CoV-2 S-protein in a transgenic mouse and a Wistar rat model. The blended low-dose bivalent mRNA vaccine contains half the mRNA of each respective monovalent vaccine, but induces comparable neutralizing antibody titres, enrichment of lung-resident memory CD8 + T cells, antigen-specific CD4 + and CD8 + responses, and protects transgenic female mice from SARS-CoV-2 lethality. The bivalent mRNA vaccine significantly reduces viral replication in both Beta- and Delta-challenged mice. Sera from bivalent mRNA vaccine immunized female Wistar rats also contain neutralizing antibodies against the B.1.1.529 (Omicron BA.1 and BA.5) variants. These data suggest that low-dose and fit-for-purpose multivalent mRNA vaccines encoding distinct S-proteins are feasible approaches for extending the coverage of vaccines for emerging and co-circulating SARS-CoV-2 variants. Here the authors show efficacy of a low-dose, unmodified, bivalent mRNA vaccine against SARS-CoV-2 variants in two female rodent models and find that combination of mRNA encoding Beta and Delta Spike sequences induces broadly neutralizing antibodies and robust T-cell responses.

Limited experimental tools are available to study the consequences of collisions between DNA-bound molecular machines. Here, we repurpose a catalytically inactivated Cas9 (dCas9) construct as a generic, novel, targetable protein–DNA roadblock for studying mechanisms underlying enzymatic activities on DNA substrates in vitro . We illustrate the broad utility of this tool by demonstrating replication fork arrest by the specifically bound dCas9–guideRNA complex to arrest viral, bacterial and eukaryotic replication forks in vitro .

Efficient and faithful replication of the genome is essential to maintain genome stability. Replication is carried out by a multiprotein complex called the replisome, which encounters numerous obstacles to its progression. Failure to bypass these obstacles results in genome instability and may facilitate errors leading to disease. Cells use accessory helicases that help the replisome bypass difficult barriers. All eukaryotes contain the accessory helicase Pif1, which tracks in a 5′–3′ direction on single-stranded DNA and plays a role in genome maintenance processes. Here, we reveal a previously unknown role for Pif1 in replication barrier bypass. We use an in vitro reconstituted Saccharomyces cerevisiae replisome to demonstrate that Pif1 enables the replisome to bypass an inactive (i.e., dead) Cas9 (dCas9) R-loop barrier. Interestingly, dCas9 R-loops targeted to either strand are bypassed with similar efficiency. Furthermore, we employed a singlemolecule fluorescence visualization technique to show that Pif1 facilitates this bypass by enabling the simultaneous removal of the dCas9 protein and the R-loop. We propose that Pif1 is a general displacement helicase for replication bypass of both R-loops and protein blocks.

Purpose Recent studies indicate that circulating microRNAs in serum/plasma are a novel class of non-invasive biomarkers with diagnostic and prognostic information. So far, circulating microRNAs have not been analyzed in patients with bladder cancer. Methods We collected serum from patients with non-muscle invasive bladder cancer (NMIBC), muscle invasive bladder cancer (MIBC) and non-malignant urological disease. Total RNA was isolated from 400 μl of serum using the mirVana PARIS Kit; the artificial cel-miR-39 was spiked-in prior to RNA isolation to control different RNA isolation efficiencies. Quantitative real-time PCR was applied to measure the levels of 22 microRNAs upregulated in BCA tissue (miR-15a, miR-18a, miR-21, miR-93, miR-96, miR-103, miR-130b, miR-135b, miR-141, miR-182, miR-183, miR-190, miR-191, miR-200b, miR-422b, miR-425, miR-449b, miR-601, miR-639, miR-644, miR-649 and miR-1233) in the marker identification cohort (NMIBC, n  = 11, MIBC, n  = 10; controls, n  = 10). The most promising serum microRNAs were tested in a validation cohort (NMIBC, n  = 65, MIBC, n  = 61; controls, n  = 105). Results The RNA recovery was similar in patients with NMIBC, MIBC and control subjects. The analysis of serum microRNA levels in the marker identification cohort indicated that serum miR-141 and miR-639 levels were increased in bladder cancer patients compared to CTRL. The analysis of these miR-141 and miR-639 in the validation cohort demonstrated that microRNA levels were similar in bladder cancer patients and control subjects. Furthermore, microRNA levels were not correlated with clinicopathological parameters (pT-stage, metastasis, grading). Conclusions The analysis of serum miR-141 and miR-639 levels does not seem to be helpful in the diagnosis or prognosis of BCA.

Epigenetic alterations play an important role in carcinogenesis. Recent studies have suggested that global histone modifications are predictors of cancer recurrence in various tumor entities. Global histone acetylation levels (histone H3 lysine 9 acetylation [H3K9Ac], histone H3 lysine 18 acetylation [H3K18Ac], total histone H3 acetylation [H3Ac] and total histone H4 acetylation [H4Ac]) were determined in patients with renal cell carcinoma (RCC) using immunohistochemistry in a tissue micro array with 193 RCC and 10 oncocytoma specimens. The histone acetylation pattern was not different among the diverse histological subtypes of RCC or oncocytoma samples. The H3Ac levels were inversely correlated with pT‐stage (P = 0.005), distant metastasis (P = 0.036), Fuhrman grading (P = 0.001) and RCC progression (P = 0.029, hazard ratio 0.87). H4Ac deacetylation was correlated with pT‐stage (P = 0.011) and grading (P = 0.029). H3K18Ac levels were an independent predictor of cancer‐progression following surgery for localized RCC in the univariate (P = 0.001, hazard ratio 0.78) and multivariate (P = 0.005, hazard ratio 0.82) analysis. In conclusion, our study supports the concept of global histone modification levels as a universal cancer prognosis marker, and provides evidence for the use of histone deacetylases inhibitors as future drugs in the therapy of RCC. (Cancer Sci 2010; 101: 2664–2669)

Coherent two-dimensional spectroscopy is a powerful tool for probing ultrafast quantum dynamics in complex systems. Several variants offer different types of information but typically require distinct beam geometries. Here we introduce population-based three-dimensional (3D) electronic spectroscopy and demonstrate the extraction of all fourth- and multiple sixth-order nonlinear signal contributions by employing 125-fold (1⨯5⨯5⨯5) phase cycling of a four-pulse sequence. Utilizing fluorescence detection and shot-to-shot pulse shaping in single-beam geometry, we obtain various 3D spectra of the dianion of TIPS-tetraazapentacene, a fluorophore with limited stability at ambient conditions. From this, we recover previously unknown characteristics of its electronic two-photon state. Rephasing and nonrephasing sixth-order contributions are measured without additional phasing that hampered previous attempts using noncollinear geometries. We systematically resolve all nonlinear signals from the same dataset that can be acquired in 8 min. The approach is generalizable to other incoherent observables such as external photoelectrons, photocurrents, or photoions. Multidimensional spectroscopic tools are important to explore the details of molecular dynamics. Here the authors use shaped pulses to demonstrate a 3D fluorescence spectroscopy method to extract the fourth and higher-order nonlinear responses in light-molecule interaction.