1,720,989 research outputs found
Functional analysis of polymorphisms at the S1/S2 site of SARS-CoV-2 spike protein
No full textSeveral SARS-CoV-2 variants emerged that harbor mutations in the surface unit of the viral spike (S) protein that enhance infectivity and transmissibility. Here, we analyzed whether ten naturally-occurring mutations found within the extended loop harboring the S1/S2 cleavage site of the S protein, a determinant of SARS-CoV-2 cell tropism and pathogenicity, impact S protein processing and function. None of the mutations increased but several decreased S protein cleavage at the S1/S2 site, including S686G and P681H, the latter of which is found in variants of concern B.1.1.7 (Alpha variant) and B.1.1.529 (Omicron variant). None of the mutations reduced ACE2 binding and cell-cell fusion although several modulated the efficiency of host cell entry. The effects of mutation S686G on viral entry were cell-type dependent and could be linked to the availability of cathepsin L for S protein activation. These results show that polymorphisms at the S1/S2 site can modulate S protein processing and host cell entry
Amino acid residues 655 and 969 in the spike protein of Omicron subvariant BA.1 control use of TMPRSS2 versus Cathepsin L dependent entry pathways and cell tropism
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
SARS-CoV-2 Omicron sublineages show comparable cell entry but differential neutralization by therapeutic antibodies
No full textVariations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Neutralizing activity against bovine H5N1 HPAIV (clade 2.3.4.4b) in human plasma after seasonal influenza vaccination
No full textEuropean Social Fund http://dx.doi.org/10.13039/501100023651Ministry for Science and Culture of Lower Saxony http://dx.doi.org/10.13039/501100010570Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347China Scholarship Council http://dx.doi.org/10.13039/50110000454
B.1.617.2 enters and fuses lung cells with increased efficiency and evades antibodies induced by infection and vaccination
No full textAppropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Acquisition of a multibasic cleavage site does not increase MERS-CoV entry into Calu-3 human lung cells
No full textABSTRACT Human-to-human transmission of the highly pathogenic Middle East respiratory syndrome coronavirus (MERS-CoV) is currently inefficient. However, there is concern that the virus might mutate and thereby increase its transmissibility and thus pandemic potential. The pandemic SARS-CoV-2 depends on a highly cleavable furin motif at the S1/S2 site of the viral spike (S) protein for efficient lung cell entry, transmission, and pathogenicity. Here, by employing pseudotyped particles, we investigated whether augmented cleavage at the S1/S2 site also increases MERS-CoV entry into Calu-3 human lung cells. We report that polymorphism T746K at the S1/S2 cleavage site or optimization of the furin motif increases S protein cleavage but not lung cell entry. These findings suggest that, unlike what has been reported for SARS-CoV-2, a highly cleavable S1/S2 site might not augment MERS-CoV infectivity for human lung cells. IMPORTANCE The highly cleavable furin motif in the spike protein is required for robust lung cell entry, transmission, and pathogenicity of SARS-CoV-2. In contrast, it is unknown whether optimization of the furin motif in the spike protein of the pre-pandemic MERS-CoV increases lung cell entry and allows for robust human–human transmission. The present study indicates that this might not be the case. Thus, neither a naturally occurring polymorphism that increased MERS-CoV spike protein cleavage nor artificial optimization of the cleavage site allowed for increased spike-protein-driven entry into Calu-3 human lung cells.The highly cleavable furin motif in the spike protein is required for robust lung cell entry, transmission, and pathogenicity of SARS-CoV-2. In contrast, it is unknown whether optimization of the furin motif in the spike protein of the pre-pandemic MERS-CoV increases lung cell entry and allows for robust human–human transmission. The present study indicates that this might not be the case. Thus, neither a naturally occurring polymorphism that increased MERS-CoV spike protein cleavage nor artificial optimization of the cleavage site allowed for increased spike-protein-driven entry into Calu-3 human lung cells.ABSTRACT Human-to-human transmission of the highly pathogenic Middle East respiratory syndrome coronavirus (MERS-CoV) is currently inefficient. However, there is concern that the virus might mutate and thereby increase its transmissibility and thus pandemic potential. The pandemic SARS-CoV-2 depends on a highly cleavable furin motif at the S1/S2 site of the viral spike (S) protein for efficient lung cell entry, transmission, and pathogenicity. Here, by employing pseudotyped particles, we investigated whether augmented cleavage at the S1/S2 site also increases MERS-CoV entry into Calu-3 human lung cells. We report that polymorphism T746K at the S1/S2 cleavage site or optimization of the furin motif increases S protein cleavage but not lung cell entry. These findings suggest that, unlike what has been reported for SARS-CoV-2, a highly cleavable S1/S2 site might not augment MERS-CoV infectivity for human lung cells. IMPORTANCE The highly cleavable furin motif in the spike protein is required for robust lung cell entry, transmission, and pathogenicity of SARS-CoV-2. In contrast, it is unknown whether optimization of the furin motif in the spike protein of the pre-pandemic MERS-CoV increases lung cell entry and allows for robust human–human transmission. The present study indicates that this might not be the case. Thus, neither a naturally occurring polymorphism that increased MERS-CoV spike protein cleavage nor artificial optimization of the cleavage site allowed for increased spike-protein-driven entry into Calu-3 human lung cells.The highly cleavable furin motif in the spike protein is required for robust lung cell entry, transmission, and pathogenicity of SARS-CoV-2. In contrast, it is unknown whether optimization of the furin motif in the spike protein of the pre-pandemic MERS-CoV increases lung cell entry and allows for robust human–human transmission. The present study indicates that this might not be the case. Thus, neither a naturally occurring polymorphism that increased MERS-CoV spike protein cleavage nor artificial optimization of the cleavage site allowed for increased spike-protein-driven entry into Calu-3 human lung cells.Bundesministerium für Bildung und Forschung 501100002347EC | Horizon Europe| HORIZON EUROPE HealthNiedersächsisches Ministerium für Wissenschaft und Kultur 501100010570Deutsche Forschungsgemeinschaft 501100001659Deutsche Forschungsgemeinschaft 501100001659Bundesministerium für Bildung und Forschung 501100002347Deutsche Forschungsgemeinschaft 501100001659Canon Foundation EuropeMinisterium für Wissenschaft, Forschung und Kunst Baden-Württemberg 50110000354
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