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Found 37769 matches. Displaying 1761-1770
Wang ZJ, Schmidt F, Weisblum Y, Muecksch F, Barnes CO, Finkin S, Schaefer-Babajew D, Cipolla M, Gaebler C, Lieberman JA, Oliveira TY, Yang Z, Abernathy ME, Huey-Tubman KE, Hurley A, Turroja M, West KA, Gordon K, Millard KG, Ramos V, Da Silva J, Xu JL, Colbert RA, Patel R, Dizon J, Unson-O'Brien C, Shimeliovich I, Gazumyan A, Caskey M, Bjorkman PJ, Casellas R, Hatziioannou T, Bieniasz PD, Nussenzweig MC
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mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants

NATURE 2021; 592(7855):616-622
Here we report on the antibody and memory B cell responses of a cohort of 20 volunteers who received the Moderna (mRNA-1273) or Pfizer-BioNTech (BNT162b2) vaccine against SARS-CoV-2(1-4). Eight weeks after the second injection of vaccine, volunteers showed high levels of IgM and IgG anti-SARS-CoV-2 spike protein (S) and receptor-binding-domain (RBD) binding titre. Moreover, the plasma neutralizing activity and relative numbers of RBD-specific memory B cells of vaccinated volunteers were equivalent to those of individuals who had recovered from natural infection(5,6). However, activity against SARS-CoV-2 variants that encode E484K-, N501Y- or K417N/E484K/N501-mutant S was reduced by a small-but significant-margin. The monoclonal antibodies elicited by the vaccines potently neutralize SARS-CoV-2, and target a number of different RBD epitopes in common with monoclonal antibodies isolated from infected donors(5-8). However, neutralization by 14 of the 17 most-potent monoclonal antibodies that we tested was reduced or abolished by the K417N, E484K or N501Y mutation. Notably, these mutations were selected when we cultured recombinant vesicular stomatitis virus expressing SARS-CoV-2 S in the presence of the monoclonal antibodies elicited by the vaccines. Together, these results suggest that the monoclonal antibodies in clinical use should be tested against newly arising variants, and that mRNA vaccines may need to be updated periodically to avoid a potential loss of clinical efficacy.
Showalter K, Spiera R, Magro C, Agius P, Martyanov V, Franks JM, Sharma R, Geiger H, Wood TA, Zhang YX, Hale CR, Finik J, Whitfield ML, Orange DE, Gordon JK
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Machine learning integration of scleroderma histology and gene expression identifies fibroblast polarisation as a hallmark of clinical severity and improvement

ANNALS OF THE RHEUMATIC DISEASES 2021 FEB; 80(2):228-237
Objective We sought to determine histologic and gene expression features of clinical improvement in early diffuse cutaneous systemic sclerosis (dcSSc; scleroderma). Methods Fifty-eight forearm biopsies were evaluated from 26 individuals with dcSSc in two clinical trials. Histologic/immunophenotypic assessments of global severity, alpha-smooth muscle actin (aSMA), CD34, collagen, inflammatory infiltrate, follicles and thickness were compared with gene expression and clinical data. Support vector machine learning was performed using scleroderma gene expression subset (normal-like, fibroproliferative, inflammatory) as classifiers and histology scores as inputs. Comparison of w-vector mean absolute weights was used to identify histologic features most predictive of gene expression subset. We then tested for differential gene expression according to histologic severity and compared those with clinical improvement (according to the Combined Response Index in Systemic Sclerosis). Results aSMA was highest and CD34 lowest in samples with highest local Modified Rodnan Skin Score. CD34 and aSMA changed significantly from baseline to 52 weeks in clinical improvers. CD34 and aSMA were the strongest predictors of gene expression subset, with highest CD34 staining in the normal-like subset (p<0.001) and highest aSMA staining in the inflammatory subset (p=0.016). Analysis of gene expression according to CD34 and aSMA binarised scores identified a 47-gene fibroblast polarisation signature that decreases over time only in improvers (vs non-improvers). Pathway analysis of these genes identified gene expression signatures of inflammatory fibroblasts. Conclusion CD34 and aSMA stains describe distinct fibroblast polarisation states, are associated with gene expression subsets and clinical assessments, and may be useful biomarkers of clinical severity and improvement in dcSSc.
Garshick MS, Baumer Y, Dey AK, Grattan R, Ng QM, Teague HL, Yu ZX, Chen MY, Tawil M, Barrett TJ, Underberg J, Fisher EA, Krueger J, Powell-Wiley TM, Playford MP, Berger JS, Mehta NN
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Characterization of PCSK9 in the Blood and Skin of Psoriasis

JOURNAL OF INVESTIGATIVE DERMATOLOGY 2021 FEB; 141(2):308-315
Mechanisms explaining the link between psoriasis, a proinflammatory condition, and cardiovascular disease are not fully known. PCSK9 is predominantly expressed in hepatocytes as a critical regulator of lipid metabolism, and clinical trials targeting PCSK9 reduce cardiovascular disease. Independent of its role in lipid metabolism, PCSK9 levels associate with endothelial dysfunction and predict cardiovascular events. We used two separate human psoriasis cohorts and the K14-Rac1V12(-/+) murine model of psoriasis to investigate PCSK9 and cardiovascular risk in psoriasis. In both psoriasis cohorts (n = 88 and n = 20), PCSK9 levels were 20% and 13% higher than in age-, sex-, and cholesterol-matched controls, respectively (P < 0.05 for each comparison) and correlated with PASI (r = 0.43, P < 0.05). Despite no difference in hepatocyte expression, K14-Rac1V12(-/+) mice demonstrated skin-specific PCSK9 staining, which was confirmed in human psoriatic lesional skin. In patients with psoriasis, PCSK9 levels correlated with impaired endothelial vascular health (e.g., early atherosclerosis, beta = 4.5, P < 0.01) and log converted coronary artery calcium score (beta = 0.30, P = 0.01), which remained significant after adjustment for Framingham risk, body mass index, and active biologic use. Taken together, these findings suggest, independent of cholesterol, an association between circulating PCSK9 and early as well as advanced stages of atherosclerosis in psoriasis.
Pan CH, Chien SC, Chen CJ, Shih CM, Hsieh MH, Huang CY, Bi WF, Chan CS, Kao YT, Hsiao CY, Chiang SJ, Chiang KH, Huang JH, Liu YR, Luo JD, Huang HY, Wu CH
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Circulating level of microRNA-142-5p is a potential biomarker for predicting in-stent restenosis: a case-control study

BMC CARDIOVASCULAR DISORDERS 2021 FEB 8; 21(1):? Article 77
BackgroundPatients who receive percutaneous coronary intervention (PCI) have different chances of developing in-stent restenosis (ISR). To date, no predictable biomarker can be applied in the clinic. MicroRNAs (miRNAs or miRs) play critical roles in transcription regulation, and their circulating levels were reported to have potential as clinical biomarkers.MethodsIn total, 93 coronary stent-implanted patients without pregnancy, liver or renal dysfunction, malignancy, hemophilia, or autoimmune diseases were recruited in this clinical study. All recruited participants were divided into an ISR group (n=45) and a non-ISR group (n=48) based on their restenotic status as confirmed by cardiologists at the first follow-up visit (6 months after surgery). Blood samples of all participants were harvested to measure circulating levels of miRNA candidates (miR-132, miR-142-5p, miR-15b, miR-24-2, and miR-424) to evaluate whether these circulating miRNAs can be applied as predictive biomarkers of ISR.ResultsOur data indicated that circulating levels of miR-142-5p were significantly higher in the ISR population, and results from the receiver operating characteristic (ROC) curve analysis also demonstrated superior discriminatory ability of miR-142-5p in predicting patients' restenotic status. In addition, circulating levels of miR-15b, miR-24-2, and miR-424 had differential expressions in participants with diabetes, hyperlipidemia, and hypertension, respectively.ConclusionsThe current study revealed that the circulating level of miR-142-5p has potential application as a clinical biomarker for predicting the development of ISR in stent-implanted patients.
Cohen AA, Gnanapragasam PNP, Lee YE, Hoffman PR, Ou SS, Kakutani LM, Keeffe JR, Wu HJ, Howarth M, West AP, Barnes CO, Nussenzweig MC, Bjorkman PJ
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Mosaic nanoparticles elicit cross-reactive immune responses to zoonotic coronaviruses in mice

SCIENCE 2021 FEB 12; 371(6530):735-741
Protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and SARS-related emergent zoonotic coronaviruses is urgently needed. We made homotypic nanoparticles displaying the receptor binding domain (RBD) of SARS-CoV-2 or co-displaying SARS-CoV-2 RBD along with RBDs from animal betacoronaviruses that represent threats to humans (mosaic nanoparticles with four to eight distinct RBDs). Mice immunized with RBD nanoparticles, but not soluble antigen, elicited cross-reactive binding and neutralization responses. Mosaic RBD nanoparticles elicited antibodies with superior cross-reactive recognition of heterologous RBDs relative to sera from immunizations with homotypic SARS-CoV-2-RBD nanoparticles or COVID-19 convalescent human plasmas. Moreover, after priming, sera from mosaic RBD-immunized mice neutralized heterologous pseudotyped coronaviruses as well as or better than sera from homotypic SARS-CoV-2-RBD nanoparticle immunizations, demonstrating no loss of immunogenicity against particular RBDs resulting from co-display. A single immunization with mosaic RBD nanoparticles provides a potential strategy to simultaneously protect against SARS-CoV-2 and emerging zoonotic coronaviruses.
Coffin J, Blomberg J, Fan H, Gifford R, Hatziioannou T, Lindemann D, Mayer J, Stoye J, Tristem M, Johnson W
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p ICTV Virus Taxonomy Profile: Retroviridae 2021

JOURNAL OF GENERAL VIROLOGY 2021; 102(12):? Article 001712
Viruses in the family Retroviridae are found in a wide variety of vertebrate hosts. Enveloped virions are 80-100 nm in diameter with an inner core containing the viral genome and replicative enzymes. Core morphology is often characteristic for viruses within the same genus. Replication involves reverse transcription and integration into host cell DNA, resulting in a provirus. Integration into germline cells can result in a heritable provirus known as an endogenous retrovirus. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Retroviridae, which is available at ictv.global/ report/retroviridae.
Hao ZT, Epshtein V, Kim KH, Proshkin S, Svetlov V, Kamarthapu V, Bharati B, Mironov A, Walz T, Nudler E
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Pre-termination Transcription Complex: Structure and Function

MOLECULAR CELL 2021 JAN 21; 81(2):281-292.e8
Rho is a general transcription termination factor playing essential roles in RNA polymerase (RNAP) recycling, gene regulation, and genomic stability in most bacteria. Traditional models of transcription termination postulate that hexameric Rho loads onto RNA prior to contacting RNAP and then translocates along the transcript in pursuit of the moving RNAP to pull RNA from it. Here, we report the cryoelectron microscopy (cryo-EM) structures of two termination process intermediates. Prior to interacting with RNA, Rho forms a specific "pre-termination complex'' (PTC) with RNAP and elongation factors NusA and NusG, which stabilize the PTC. RNA exiting RNAP interacts with NusA before entering the central channel of Rho from the distal C-terminal side of the ring. We map the principal interactions in the PTC and demonstrate their critical role in termination. Our results support a mechanism in which the formation of a persistent PTC is a prerequisite for termination.
Mayle R, O'Donnell M
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Expression of recombinant multi-protein complexes in Saccharomyces cerevisiae

RECOMBINANT PROTEIN EXPRESSION: EUKARYOTIC HOSTS 2021; 660(?):3-20
Baker's yeast, Saccharomyces cerevisiae, is a versatile system for expression of recombinant eukaryotic proteins. This system is simple to use and does not require extraordinary expertise nor tissue culture facilities. Proteins expressed in the yeast system provide eukaryotic post-translational modifications, making it superior to bacterial expression for factors that require post-translational modification. In addition, it is quite simple to co-express multiple genes at the same time, for recombinant production of large multi-protein complexes. In this chapter, we provide protocols for inducible expression of recombinant genes from episomal plasmid vectors, and protocols for integration of the recombinant genes into the chromosomes of yeast, which enables simple rapid growth of expression cells and induction of recombinant protein complexes in non-selectable rich media.
Ceraudo E, Horioka M, Mattheisen JM, Hitchman TD, Moore AR, Kazmi MA, Chi P, Chen Y, Sakmar TP, Huber T
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Direct evidence that the GPCR CysLTR2 mutant causative of uveal melanoma is constitutively active with highly biased signaling

JOURNAL OF BIOLOGICAL CHEMISTRY 2021 JAN-JUN; 296(?):? Article 100163
Uveal melanoma is the most common eye cancer in adults and is clinically and genetically distinct from skin cutaneous melanoma. In a subset of cases, the oncogenic driver is an activating mutation in CYSLTR2, the gene encoding the G protein-coupled receptor cysteinyl-leukotriene receptor 2 (CysLTR2). The mutant CYSLTR2 encodes for the CysLTR2-L129Q receptor, with the substitution of Leu to Gln at position 129 (3.43). The ability of CysLTR2-L129Q to cause malignant transformation has been hypothesized to result from constitutive activity, but how the receptor could escape desensitization is unknown. Here, we characterize the functional properties of CysLTR2-L129Q. We show that CysLTR2-L129Q is a constitutively active mutant that strongly drives Gq/11 signaling pathways. However, CysLTR2-L129Q only poorly recruits beta-arrestin. Using a modified Slack-Hall operational model, we quantified the constitutive activity for both pathways and conclude that CysLTR2-L129Q displays profound signaling bias for Gq/11 signaling pathways while escaping beta-arrestin-mediated down-regulation. CYSLTR2 is the first known example of a G protein-coupled receptor driver oncogene that encodes a highly biased constitutively active mutant receptor. These results provide new insights into the mechanism of CysLTR2-L129Q oncoprotein signaling and suggest CYSLTR2 as a promising potential therapeutic target in uveal melanoma.
Barros AJD, Victora CG, Menezes AMB, Horta BL, Barros FC, Hartwig FP, Victora GD, Vidaletti LP, Silveira MF, Mesenburg MA, Jacques N, Struchiner CJ, Brust FR, Dall'Agnol MM, Delamare APL, Francois CHR, Ikeda MLR, Pellegrini DCP, Reuter CP, da Silva SG, Dellagostin OA, Hallal PC
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Population-level seropositivity trend for SARS-Cov-2 in Rio Grande do Sul, Brazil

REVISTA DE SAUDE PUBLICA 2021; 55(?):? Article 78
OBJECTIVE: To describe the evolution of seropositivity in the State of Rio Grande do Sul, Brazil, through 10 consecutive surveys conducted between April 2020 and April 2021. METHODS: Nine cities covering all regions of the State were studied, 500 households in each city. One resident in each household was randomly selected for testing. In survey rounds 1-8 we used the rapid WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech Co., Guangzhou, China). In rounds 9-10, we used a direct ELISA test that identifies IgG to the viral S protein (S-UFRJ). In terms of social distancing, individuals were asked three questions, from which we generated an exposure score using principal components analysis. RESULTS: Antibody prevalence in early April 2020 was 0.07%, increasing to 10.0% in February 2021, and to 18.2% in April 2021. In round 10, self-reported whites showed the lowest seroprevalence (17.3%), while indigenous individuals presented the highest (44.4%). Seropositivity increased by 40% when comparing the most with the least exposed. CONCLUSIONS: The proportion of the population already infected by SARS-Cov-2 in the state is still far from any perspective of herd immunity and the infection affects population groups in very different levels.