Deep mutational scanning of influenza A virus NEP reveals pleiotropic mutations in its N-terminal domain.

The influenza A virus nuclear export protein (NEP) is a multifunctional protein that is essential for the viral life cycle and has very high sequence conservation. However, since the open reading frame of NEP largely overlaps with that of another influenza viral protein, non-structural protein 1, it is difficult to infer the functional constraints of NEP based on sequence conservation analysis. Besides, the N-terminal of NEP is structurally disordered, which further complicates the understanding of its function. Here, we systematically measured the replication fitness effects of >1,800 mutations of NEP. Our results show that the N-terminal domain has high mutational tolerance. Additional experiments demonstrate that N-terminal domain mutations pleiotropically affect viral transcription and replication dynamics, host cellular responses, and mammalian adaptation of avian influenza virus. Overall, our study not only advances the functional understanding of NEP, but also provides insights into its evolutionary constraints.

Stringent and complex sequence constraints of an IGHV1-69 broadly neutralizing antibody to influenza HA stem.

IGHV1-69 is frequently utilized by broadly neutralizing influenza antibodies to the hemagglutinin (HA) stem. These IGHV1-69 HA stem antibodies have diverse complementarity-determining region (CDR) H3 sequences. Besides, their light chains have minimal to no contact with the epitope. Consequently, sequence determinants that confer IGHV1-69 antibodies with HA stem specificity remain largely elusive. Using high-throughput experiments, this study reveals the importance of light-chain sequence for the IGHV1-69 HA stem antibody CR9114, which is the broadest influenza antibody known to date. Moreover, we demonstrate that the CDR H3 sequences from many other IGHV1-69 antibodies, including those to the HA stem, are incompatible with CR9114. Along with mutagenesis and structural analysis, our results indicate that light-chain and CDR H3 sequences coordinately determine the HA stem specificity of IGHV1-69 antibodies. Overall, this work provides molecular insights into broadly neutralizing antibody responses to influenza virus, which have important implications for universal influenza vaccine development.

Stringent and complex sequence constraints of an IGHV1-69 broadly neutralizing antibody to influenza HA stem.

IGHV1-69 is frequently utilized by broadly neutralizing influenza antibodies to the hemagglutinin (HA) stem. These IGHV1-69 HA stem antibodies have diverse complementarity-determining region (CDR) H3 sequences. Besides, their light chains have minimal to no contact with the epitope. Consequently, sequence determinants that confer IGHV1-69 antibodies with HA stem specificity remain largely elusive. Using high-throughput experiments, this study revealed the importance of light chain sequence for the IGHV1-69 HA stem antibody CR9114, which is the broadest influenza antibody known to date. Moreover, we demonstrated that the CDR H3 sequences from many other IGHV1-69 antibodies, including those to HA stem, were incompatible with CR9114. Along with mutagenesis and structural analysis, our results indicate that light chain and CDR H3 sequences coordinately determine the HA stem specificity of IGHV1-69 antibodies. Overall, this work provides molecular insights into broadly neutralizing antibody responses to influenza virus, which have important implications for universal influenza vaccine development.

Effect of persuasive messaging about COVID-19 vaccines for 5- to 11-year-old children on parent intention to vaccinate.

AIM: Uptake of COVID-19 vaccines for children aged 5-11 years old in Australia has plateaued. Persuasive messaging is an efficient and adaptable potential intervention to promote vaccine uptake, but evidence for its effectiveness is varied and dependent on context and cultural values. This study aimed to test persuasive messages to promote COVID-19 vaccines for children in Australia. METHODS: A parallel, online, randomised control experiment was conducted between 14 and 21 January 2022. Participants were Australian parents of a child aged 5-11 years who had not vaccinated their child with a COVID-19 vaccine. After providing demographic details and level of vaccine hesitancy, parents viewed either the control message or one of four intervention texts emphasising (i) personal health benefits; (ii) community health benefits; (iii) non-health benefits; or (iv) personal agency. The primary outcome was parents' intention to vaccinate their child. RESULTS: The analysis included 463 participants, of whom 58.7% (272/463) were hesitant about COVID-19 vaccines for children. Intention to vaccinate was higher in the community health (7.8%, 95% confidence interval (CI) -5.3% to 21.0%) and non-health (6.9%, 95% CI -6.4% to 20.3%) groups, and lower in the personal agency group (-3.9, 95% CI -17.7 to 9.9) compared to control, but these differences did not reach statistical significance. The effects of the messages among hesitant parents were similar to the overall study population. CONCLUSION: Short, text-based messages alone are unlikely to influence parental intention to vaccinate their child with the COVID-19 vaccine. Multiple strategies tailored for the target audience should also be utilised.

The Prognostic Significance of Red Cell Distribution Width in Cardiac Surgery: A Systematic Review and Meta-Analysis.

RED CELL DISTRIBUTION WIDTH (RDW) is a routinely available biomarker of likely erythropoietic dysfunction, which may be associated with adverse outcomes after cardiac surgery. This systematic review and meta-analysis aimed to clarify the prognostic value of RDW in patients undergoing cardiac surgery. The authors searched MEDLINE, Embase, and the Cochrane Library from inception to May 10, 2022 for studies investigating the association between elevated RDW (as defined by the authors of included studies) and adverse outcomes after cardiac surgery. Herein, the authors extracted maximally adjusted hazard ratios (HRs) and odds ratios (ORs) with associated CIs, and pooled them using random-effects inverse- variance modeling. The authors explored interstudy heterogeneity using metaregression. The authors included 26 studies involving 48,092 patients who had undergone cardiac surgery. Elevated preoperative RDW was associated with long-term mortality (pooled HR 1.63, 95% CI 1.05-2.52), short-term mortality (pooled OR 2.16, 95% CI 1.21-3.87), acute kidney injury (AKI; pooled OR 1.30, 95% CI 1.19-1.41) and postoperative atrial fibrillation (POAF; pooled OR 1.44, 95% CI 1.05-1.96). Some studies suggested a significant association between preoperative RDW elevation and neurologic complications; however, their number was insufficient for meta-analysis. The postoperative RDW levels were less consistently reported and could not be meta-analyzed. In conclusion, the authors found that elevated preoperative RDW was associated with increased short- and long-term mortality, POAF, and AKI after cardiac surgery. Further research is needed to investigate its role in the risk stratification of patients undergoing cardiac surgery.

Paramagnetic effects on the NMR spectra of isotropic bicelles with headgroup modified chelator lipids and metal ions.

We characterized the paramagnetic effects of nine metal ions on NMR signals of isotropic bicelles with headgroup-modified lipids. We found that Mn(2+), Gd(3+) and Dy(3+) show evidence for influencing NMR signals on the surface more than inside and on the disc edge, providing distance information in the bilayers.