Critical patients with the coronavirus disease 2019 (COVID-19), even those whose nucleic acid test results had turned negative and those receiving maximal medical support, have been noted to progress ...to irreversible fatal respiratory failure. Lung transplantation (LT) as the sole therapy for end-stage pulmonary fibrosis related to acute respiratory distress syndrome has been considered as the ultimate rescue therapy for these patients.
From February 10 to March 10, 2020, three male patients were urgently assessed and listed for transplantation. After conducting a full ethical review and after obtaining assent from the family of the patients, we performed three LT procedures for COVID-19 patients with illness durations of more than one month and extremely high sequential organ failure assessment scores.
Two of the three recipients survived post-LT and started participating in a rehabilitation program. Pearls of the LT team collaboration and perioperative logistics were summarized and continually improved. The pathological results of the explanted lungs were concordant with the critical clinical manifestation, and provided insight towards better understanding of the disease. Government health affair systems, virology detection tools, and modern communication technology all play key roles towards the survival of the patients and their rehabilitation.
LT can be performed in end-stage patients with respiratory failure due to COVID-19-related pulmonary fibrosis. If confirmed positive-turned-negative virology status without organ dysfunction that could contraindicate LT, LT provided the final option for these patients to avoid certain death, with proper protection of transplant surgeons and medical staffs. By ensuring instant seamless care for both patients and medical teams, the goal of reducing the mortality rate and salvaging the lives of patients with COVID-19 can be attained.
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.
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.
The combination of immunotherapy and antiangiogenic agents for the treatment of refractory solid tumor has not been well investigated. Thus, our study aimed to evaluate the efficacy and safety of a ...new regimen of anlotinib plus PD‐1 inhibitor to treat refractory solid tumor. APICAL‐RST is an investigator‐initiated, open‐label, single‐arm, phase II trial in patients with heavily treated, refractory, metastatic solid tumor. Eligible patients experienced disease progression during prior therapy without further effective regimen. All patients received anlotinib and PD‐1 inhibitor. The primary endpoints were objective response and disease control rates. The secondary endpoints included the ratio of progression‐free survival 2 (PFS2)/PFS1, overall survival (OS) and safety. Forty‐one patients were recruited in our study; 9 patients achieved a confirmed partial response and 21 patients had stable disease. Objective response rate and disease control rate were 22.0% and 73.2% in the intention‐to‐treat cohort, and 24.3% and 81.1% in the efficacy‐evaluable cohort, respectively. A total of 63.4% (95% confidence interval CI: 46.9%‐77.4%) of the patients (26/41) presented PFS2/PFS1 >1.3. The median OS was 16.8 months (range: 8.23‐24.4), and the 12‐ and 36‐month OS rates were 62.8% and 28.9%, respectively. No significant association was observed between concomitant mutation and efficacy. Thirty‐one (75.6%) patients experienced at least one treatment‐related adverse event. The most common adverse events were hypothyroidism, hand‐foot syndrome and malaise. This phase II trial showed that anlotinib plus PD‐1 inhibitor exhibits favorable efficacy and tolerability in patients with refractory solid tumor.
What's new?
The combination of immunotherapy and antiangiogenic agents for the treatment of refractory solid tumors remains to be further investigated. Here, the authors conducted the prospective, single‐arm, nonrandomized, phase II APICAL‐RST trial to investigate the efficacy and safety of the oral multikinase inhibitor anlotinib plus PD‐1 inhibitor in refractory solid tumors. The regimen demonstrated substantial clinical activity and manageable toxicity among heavily pretreated, pan‐cancer patients. The clinical benefits were consistent across different histological or molecular subgroups. The results from the APICAL‐RST trial support anlotinib plus PD‐1 inhibitor as an effective regimen in heavily‐treated, refractory, metastatic solid tumors.
The Majorana fermion, which is its own antiparticle and obeys non-Abelian statistics, plays a critical role in topological quantum computing. It can be realized as a bound state at zero energy, ...called a Majorana zero mode (MZM), in the vortex core of a topological superconductor, or at the ends of a nanowire when both superconductivity and strong spin orbital coupling are present. A MZM can be detected as a zero-bias conductance peak (ZBCP) in tunneling spectroscopy. However, in practice, clean and robust MZMs have not been realized in the vortices of a superconductor because of contamination from impurity states or other closely packed Caroli–de Gennes-Matricon (CdGM) states, which hampers further manipulations of MZMs. Here, using scanning tunneling spectroscopy, we show that a ZBCP well separated from the other discrete CdGM states exists ubiquitously in the cores of free vortices in the defect-free regions of(Li0.84Fe0.16)OHFeSe, which has a superconducting transition temperature of 42 K. Moreover, a Dirac-cone-type surface state is observed by angle-resolved photoemission spectroscopy, and its topological nature is confirmed by band calculations. The observed ZBCP can naturally be attributed to a MZM arising from the chiral topological surface state of a bulk superconductor. Thus,(Li0.84Fe0.16)OHFeSeprovides an ideal platform for studying MZMs and topological quantum computing.
Background & Aims
Patatin‐like phospholipase domain‐containing protein 3 (PNPLA3) rs738409 polymorphism is associated with NAFLD severity and the PNPLA3 gene is expressed in the kidneys, but whether ...PNPLA3 rs738409 polymorphism is also associated with renal tubular injury (RTI) is uncertain. We assessed the effect of PNPLA3 genotypes on biomarkers of RTI and glomerular function in subjects with NAFLD who had either normal (nALT) or abnormal (abnALT) alanine aminotransaminase levels.
Methods
Two hundred and seventeen patients with histologically proven NAFLD of which 75 had persistently nALT (below upper limit of normal for 3 months) were included. Multivariable regression analyses were undertaken to test associations between PNPLA3 genotype and biomarkers of kidney dysfunction.
Results
The nALT patient group had higher urinary neutrophil gelatinase‐associated lipocalin levels (u‐NGAL, a biomarker of RTI) (P < .001), higher albuminuria (P = .039) and greater prevalence of chronic kidney disease (CKD; P = .046) than the abnALT group. The association between PNPLA3 GG genotype and risk of CKD and abnormal albuminuria remained significant after adjustment for kidney risk factors and severity of NAFLD histology, mostly in the nALT group. Similarly, PNPLA3 GG genotype was associated with higher u‐NGAL levels in the nALT group, even after adjustment for the aforementioned risk factors and glomerular filtration‐based markers (β‐coefficient: 22.29, 95% CI: 0.99‐43.60, P = .041).
Conclusion
Patients with NAFLD and persistently nALT, who carry the PNPLA3 rs738409 G allele, are at higher risk of early glomerular and tubular damage. We suggest PNPLA3 genotyping may help identify patients with NAFLD at higher risk of RTI.
The limitations of liver biopsy have led to the development of indirect noninvasive models for liver fibrosis assessment. We aimed to evaluate and compare the performance of 30 noninvasive models to ...predict fibrosis stage in treatment‐naïve and treated chronic hepatitis B (CHB) patients. A total of 576 Chinese treatment‐naïve CHB patients and 236 treated CHB patients who had undergone percutaneous liver biopsy were included in the analysis. Histological grading and staging was assessed by the Ishak scoring system. The diagnostic accuracies of 30 noninvasive models were assessed by area under the receiver operating characteristic curves (AUROCs). In treatment‐naïve CHB patients, the AUROCs of the 30 noninvasive models for discriminating significant fibrosis (SF) were less than 0.800, and only the AUROC of the PP score for diagnosing advanced fibrosis (AF) was more than 0.800, while the AUROCs of FIB‐4, FibroQ, HB‐F, Lok index, PHP score and PP score for predicting cirrhosis were greater than 0.800. In treated CHB patients, only the AUROCs of APRI, GUCI, King's score and Wang I for identifying cirrhosis were more than 0.800. The Spearman correlation analysis identified that only the changes in FCI and Virahep‐C model values were weakly correlated with changes in Ishak fibrosis scores before and after treatment (r = 0.206, p = 0.008; r = 0.187, p = 0.016, respectively). In conclusion, in Chinese CHB patients, the 30 existing noninvasive models were not suitable for assessing each stage of fibrosis except cirrhosis before and after antiviral therapy, especially in gauging progression and regression of liver fibrosis following therapy.
High frequency of recurrence is the major cause of the poor outcomes for patients with hepatocellular carcinoma (HCC). microRNA (miR)-182-5p emerged as a high-priority miRNA in HCC and was found to ...be related to HCC metastasis. Whether the expression of miR-182-5p in tumor tissue correlated with early recurrence in HCC patients underwent curative surgery was unknown.
Real-time PCR (RT-PCR) and in situ hybridization (ISH) were conducted to assess the expression of miR-182-5p in HCC cells and tissues. Cell Counting Kit-8 (CCK-8), transwell assays were performed to detected cells proliferation and migration ability. Flow cytometry assays were used to detect cell apoptosis rate, and xenograft model was employed to study miR-182-5p in HCC growth and lung metastasis. The target of miR-182-5p was validated with a dual-luciferase reporter assay and western blotting. Immunohistochemistry, immumoblotting, and immunoprecipitation were performed to test relative protein expression.
We showed that high expression of miR-182-5p in tumor tissues correlated with poor prognosis as well as early recurrence in HCC patients underwent curative surgery. miR-182-5p enhanced motility and invasive ability of HCC cells both in vitro and in vivo. miR-182-5p directly targets 3'-UTR of FOXO3a and repressed FOXO3a expression, activating AKT/FOXO3a pathway to promote HCC proliferation. Notably, miR-182-5p activated Wnt/β-catenin signaling by inhibiting the degradation of β-catenin and enhancing the interaction between β-catenin and TCF4 which was mediated by repressed FOXO3a.
Consistently, miR-182-5p can be a potential predictor of early recurrence for HCC patients underwent curative surgery, and FOXO3a plays a key mediator in miR-182-5p induced HCC progression.
Probing Allostery Through DNA Kim, Sangjin; Broströmer, Erik; Xing, Dong ...
Science (American Association for the Advancement of Science),
02/2013, Volume:
339, Issue:
6121
Journal Article
Peer reviewed
Open access
Allostery is well documented for proteins but less recognized for DNA-protein interactions. Here, we report that specific binding of a protein on DNA is substantially stabilized or destabilized by ...another protein bound nearby. The ternary complex's free energy oscillates as a function of the separation between the two proteins with a periodicity of ∼10 base pairs, the helical pitch of B-form DNA, and a decay length of ∼15 base pairs. The binding affinity of a protein near a DNA hairpin is similarly dependent on their separation, which—together with molecular dynamics simulations—suggests that deformation of the double-helical structure is the origin of DNA allostery. The physiological relevance of this phenomenon is illustrated by its effect on gene expression in live bacteria and on a transcription factor's affinity near nucleosomes.
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