The COVID-19 pandemic urgently needs therapeutic and prophylactic interventions. Here, we report the rapid identification of SARS-CoV-2-neutralizing antibodies by high-throughput single-cell RNA and ...VDJ sequencing of antigen-enriched B cells from 60 convalescent patients. From 8,558 antigen-binding IgG1+ clonotypes, 14 potent neutralizing antibodies were identified, with the most potent one, BD-368-2, exhibiting an IC50 of 1.2 and 15 ng/mL against pseudotyped and authentic SARS-CoV-2, respectively. BD-368-2 also displayed strong therapeutic and prophylactic efficacy in SARS-CoV-2-infected hACE2-transgenic mice. Additionally, the 3.8 Å cryo-EM structure of a neutralizing antibody in complex with the spike-ectodomain trimer revealed the antibody’s epitope overlaps with the ACE2 binding site. Moreover, we demonstrated that SARS-CoV-2-neutralizing antibodies could be directly selected based on similarities of their predicted CDR3H structures to those of SARS-CoV-neutralizing antibodies. Altogether, we showed that human neutralizing antibodies could be efficiently discovered by high-throughput single B cell sequencing in response to pandemic infectious diseases.
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•8,558 IgG1+ antigen-binding clonotypes were identified by high-throughput scRNA/VDJ-seq•14 potent SARS-CoV-2 neutralizing antibodies were found from 60 convalescent patients•BD-368-2 showed high therapeutic and prophylactic efficacy in SARS-CoV-2-infected mice•Neutralizing antibodies can be directly selected based on predicted CDR3H structures
Neutralizing antibodies, which could effectively block virus entry into host cells, are urgently needed for intervention against COVID-19. Using high-throughput single-cell RNA sequencing, Cao et al. identified fourteen potent neutralizing antibodies from 60 convalescent patients’ B cells. The most potent antibody, BD-368-2, exhibits high therapeutic and prophylactic efficacy in SARS-CoV-2-infected mice.
Recycling of waste is critical for sustainability. Modern industrialization has caused a rapid decline in natural resources, and a dramatic rise in hazardous pollutants released into the environment. ...A recent study reported that global resource usage rose from 23.7 billion tons in 1970 to 70.1 billion tons in 2010. Global consumption of metals has increased at a significant pace, placing severe environmental and economic pressure for recycling. Electrochemical processes are particularly well suited for metal recovery. Due to the ionic nature of the metals after leaching, both Faradaic and non-Faradaic electrochemical processes can play an important role in separating and purifying these elements. Here, an overview of electrochemical approaches for chemical recycling will be presented, with a focus on metal recovery from electronic waste, battery components, as well as methods for selective recycling specialty metals and rare earth elements. This article discusses emerging recycling methods for value-added compounds beyond metals, including organic compounds, which may point to new directions in chemical recycling. In sum, electrochemical separation processes are expected to play a significant role in waste recycling and contribute towards a sustainable circular economy.
Understanding how potent neutralizing antibodies (NAbs) inhibit SARS-CoV-2 is critical for effective therapeutic development. We previously described BD-368-2, a SARS-CoV-2 NAb with high potency; ...however, its neutralization mechanism is largely unknown. Here, we report the 3.5-Å cryo-EM structure of BD-368-2/trimeric-spike complex, revealing that BD-368-2 fully blocks ACE2 recognition by occupying all three receptor-binding domains (RBDs) simultaneously, regardless of their “up” or “down” conformations. Also, BD-368-2 treats infected adult hamsters at low dosages and at various administering windows, in contrast to placebo hamsters that manifested severe interstitial pneumonia. Moreover, BD-368-2’s epitope completely avoids the common binding site of VH3-53/VH3-66 recurrent NAbs, evidenced by tripartite co-crystal structures with RBDs. Pairing BD-368-2 with a potent recurrent NAb neutralizes SARS-CoV-2 pseudovirus at pM level and rescues mutation-induced neutralization escapes. Together, our results rationalized a new RBD epitope that leads to high neutralization potency and demonstrated BD-368-2’s therapeutic potential in treating COVID-19.
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•BD-368-2 blocks all three ACE2 binding sites regardless of RBD spatial conformations•BD-368-2 treats severely infected hamsters at low dosages and various dose windows•New cocktail design based on BD-368-2 neutralizes escaping SARS-CoV-2 mutants
Du et al. showed how a potent COVID-19 antibody, BD-368-2, interacts with the SARS-CoV-2 spike trimer to neutralize the virus and effectively treat severely infected hamsters. They further demonstrated how BD-368-2 can be paired with additional antibodies to form a cocktail that prevents the evolution of viral escape mutants.
G-quadruplex is a special secondary structure of nucleic acids in guanine-rich sequences of genome. G-quadruplexes have been proved to be involved in the regulation of replication, DNA damage repair, ...and transcription and translation of oncogenes or other cancer-related genes. Therefore, targeting G-quadruplexes has become a novel promising anti-tumor strategy. Different kinds of small molecules targeting the G-quadruplexes have been designed, synthesized, and identified as potential anti-tumor agents, including molecules directly bind to the G-quadruplex and molecules interfering with the binding between the G-quadruplex structures and related binding proteins. This review will explore the feasibility of G-quadruplex ligands acting as anti-tumor drugs, from basis to application. Meanwhile, since helicase is the most well-defined G-quadruplex-related protein, the most extensive research on the relationship between helicase and G-quadruplexes, and its meaning in drug design, is emphasized.
The development of enantioconvergent cross‐coupling of racemic alkyl halides directly with heteroarene C(sp2)−H bonds has been impeded by the use of a base at elevated temperature that leads to ...racemization. We herein report a copper(I)/cinchona‐alkaloid‐derived N,N,P‐ligand catalytic system that enables oxidative addition with racemic alkyl bromides under mild conditions. Thus, coupling with azole C(sp2)−H bonds has been achieved in high enantioselectivity, affording a number of potentially useful α‐chiral alkylated azoles, such as 1,3,4‐oxadiazoles, oxazoles, and benzodoxazoles as well as 1,3,4‐triazoles, for drug discovery. Mechanistic experiments indicated facile deprotonation of an azole C(sp2)−H bond and the involvement of alkyl radical species under the reaction conditions.
The use of a cinchona‐alkaloid‐derived N,N,P‐ligand leads to the direct enantioconvergent coupling of racemic alkyl bromides with azole C(sp2)−H bonds by copper catalysis. The key to success is the ligand‐enabled facile oxidative addition at approximately room temperature that suppresses product racemization at elevated temperature. This method provides a range of enantioenriched α‐chiral alkylated azoles.
The COVID-19 pandemic caused by the SARS-CoV-2 virus has led to more than 270 million infections and 5.3 million of deaths worldwide. Several major variants of SARS-CoV-2 have emerged and posed ...challenges in controlling the pandemic. The recently occurred Omicron variant raised serious concerns about reducing the efficacy of vaccines and neutralization antibodies due to its vast mutations. We have modelled the complex structure of the human ACE2 protein and the receptor binding domain (RBD) of Omicron Spike protein (S-protein), and conducted atomistic molecular dynamics simulations to study the binding interactions. The analysis shows that the Omicron RBD binds more strongly to the human ACE2 protein than the original strain. The mutations at the ACE2-RBD interface enhance the tight binding by increasing hydrogen bonding interaction and enlarging buried solvent accessible surface area.
•Structure prediction and refinement of SARS-CoV-2 spike protein RBD-ACE2 complex for Omicron variant.•Molecular dynamics simulations reveal stronger binding interactions between RBD and ACE2 protein in Omicron.•Mutations on Omicron RBD yield more hydrogen bonds, residue contacts and larger buried surface at the ACE2-RBD interface.
The sigma (σ)‐hole effect has emerged as a promising tool to construct novel architectures endowed with new properties. A simple yet effective strategy for the generation of monofluoromethyl radicals ...is a continuing challenge within the synthetic community. Fluoromethylphosphonium salts are easily available, air‐ and thermally stable, as well as simple‐to‐handle. Herein, we report the ability of the σ‐hole effect to facilitate the visible‐light‐triggered photolysis of phosphonium iodide salts, a charge‐transfer complex, selectively giving fluoromethyl radicals. The usefulness and versatility of this new protocol are demonstrated through the mono‐, di‐, and trifluoromethylation of a variety of alkenes.
Simple and selective synthesis of fluoromethylated alkenes, heterocycles, enamines and heteroarenes by using the readily available and bench‐stable fluoromethylphosphonium iodide salts is described. Key to this privileged transformation is the formation of a photoactive charge‐transfer complex involving the σ‐hole effect of phosphonium salts.
The cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) mediates innate immune responses against invading pathogens, or against self-dsDNA, which causes autoimmune disorders. Upon nonspecific binding ...of cytosolic B-form DNA, cGAS synthesizes the second messenger 2'3'-cGAMP and triggers STING-dependent signaling to produce type I IFNs. The cGAS comprises less-conserved N-terminal residues and highly conserved nucleotidyltransferase/Mab21 domains. The function and structure of the well-conserved domains have been extensively studied, whereas the physiological function of the N-terminal domain of cGAS is largely uncharacterized. In this study we used a single-molecule technique combined with traditional biochemical and cellular assays to demonstrate that binding of nonspecific dsDNA by the N-terminal domain of cGAS promotes its activation. We have observed that the N terminus of human cGAS (
cGAS-N160) undergoes secondary structural change upon dsDNA binding in solution. Furthermore, we showed that the
cGAS-N160 helps full length
cGAS to expand the binding range on λDNA and facilitates its binding efficiency to dsDNA compared with
cGAS without the 160 N-terminal residues (
cGAS-d160). More importantly,
cGAS-N160 endows full length
cGAS relatively higher enzyme activity and stronger activation of STING/IRF3-mediated cytosolic DNA signaling. These findings strongly indicate that the N-terminal domain of cGAS plays an important role in enhancing its function.
Kir4.1 in the distal convoluted tubule plays a key role in sensing plasma potassium and in modulating the thiazide-sensitive sodium-chloride cotransporter (NCC). Here we tested whether dietary ...potassium intake modulates Kir4.1 and whether this is essential for mediating the effect of potassium diet on NCC. High potassium intake inhibited the basolateral 40 pS potassium channel (a Kir4.1/5.1 heterotetramer) in the distal convoluted tubule, decreased basolateral potassium conductance, and depolarized the distal convoluted tubule membrane in Kcnj10flox/flox mice, herein referred to as control mice. In contrast, low potassium intake activated Kir4.1, increased potassium currents, and hyperpolarized the distal convoluted tubule membrane. These effects of dietary potassium intake on the basolateral potassium conductance and membrane potential in the distal convoluted tubule were completely absent in inducible kidney-specific Kir4.1 knockout mice. Furthermore, high potassium intake decreased, whereas low potassium intake increased the abundance of NCC expression only in the control but not in kidney-specific Kir4.1 knockout mice. Renal clearance studies demonstrated that low potassium augmented, while high potassium diminished, hydrochlorothiazide-induced natriuresis in control mice. Disruption of Kir4.1 significantly increased basal urinary sodium excretion but it abolished the natriuretic effect of hydrochlorothiazide. Finally, hypokalemia and metabolic alkalosis in kidney-specific Kir4.1 knockout mice were exacerbated by potassium restriction and only partially corrected by a high-potassium diet. Thus, Kir4.1 plays an essential role in mediating the effect of dietary potassium intake on NCC activity and potassium homeostasis.
This study evaluated the effects of pretransplantation minimal residual disease (pre‐MRD) on outcomes of patients with acute lymphoblastic leukemia (ALL) who underwent unmanipulated haploidentical ...stem cell transplantation (haplo‐SCT). A retrospective study including 543 patients with ALL was performed. MRD was determined using multiparametric flow cytometry. Both in the entire cohort of patients and in subgroup cases with T‐ALL or B‐ALL, patients with positive pre‐MRD had a higher incidence of relapse (CIR) than those with negative pre‐MRD in MSDT settings (P < 0.01 for all). Landmark analysis at 6 months showed that MRD positivity was significantly and independently associated with inferior rates of relapse (HR, 1.908; P = 0.007), leukemia‐free survival (LFS) (HR, 1.559; P = 0.038), and OS (HR, 1.545; P = 0.049). The levels of pre‐MRD according to a logarithmic scale were also associated with leukemia relapse, LFS, and OS, except that cases with MRD <0.01% experienced comparable CIR and LFS to those with negative pre‐MRD. A risk score for CIR was developed using the variables pre‐MRD, disease status, and immunophenotype of ALL. The CIR was 14%, 26%, and 59% for subjects with scores of 0, 1, and 2‐3, respectively (P < 0.001). Three‐year LFS was 75%, 64%, and 42%, respectively (P < 0.001). Multivariate analysis confirmed the association of the risk score with CIR and LFS. The results indicate that positive pre‐MRD, except for low level one (MRD < 0.01%), is associated with poor outcomes in patients with ALL who underwent unmanipulated haplo‐SCT.
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