RESUMO
Novel bat H17N10 and H18N11 influenza A viruses (IAVs) are incapable of reassortment with conventional IAVs during co-infection. To date, the underlying mechanisms that inhibit bat and conventional IAV reassortment remain poorly understood. Herein, we used the bat influenza M gene in the PR8 H1N1 virus genetic background to determine the molecular basis that restricts reassortment of segment 7. Our results showed that NEP and M1 from bat H17N10 and H18N11 can interact with PR8 M1 and NEP, resulting in mediating PR8 viral ribonucleoprotein (vRNP) nuclear export and formation of virus-like particles with single vRNP. Further studies demonstrated that the incompatible packaging signals (PSs) of H17N10 or H18N11 M segment led to the failure to rescue recombinant viruses in the PR8 genetic background. Recombinant PR8 viruses (rPR8psH18M and rPR8psH17M) containing bat influenza M coding region flanked with the PR8 M PSs were rescued but displayed lower replication in contrast to the parental PR8 virus, which is due to a low efficiency of recombinant virus uncoating correlating with the functions of the bat M2. Our studies reveal molecular mechanisms of the M gene that hinder reassortment between bat and conventional IAVs, which will help to understand the biology of novel bat IAVs. IMPORTANCE: Reassortment is one of the mechanisms in fast evolution of influenza A viruses (IAVs) and responsible for generating pandemic strains. To date, why novel bat IAVs are incapable of reassorting with conventional IAVs remains completely understood. Here, we attempted to rescue recombinant PR8 viruses with M segment from bat IAVs to understand the molecular mechanisms in hindering their reassortment. Results showed that bat influenza NEP and M1 have similar functions as respective counterparts of PR8 to medicating viral ribonucleoprotein nuclear export. Moreover, the incompatible packaging signals of M genes from bat and conventional IAVs and impaired bat M2 functions are the major reasons to hinder their reassortment. Recombinant PR8 viruses with bat influenza M open reading frames were generated but showed attenuation, which correlated with the functions of the bat M2 protein. Our studies provide novel insights into the molecular mechanisms that restrict reassortment between bat and conventional IAVs.
RESUMO
We present a conceptual framework of situational moderators of gender/sex effects in negotiation, risk-taking, and leadership-three masculine-stereotypic domains associated with gender/sex gaps in pay and authority. We propose that greater situational ambiguity and higher relevance and salience of gender/sex increase the likelihood of gender/sex-linked behaviors in these domains. We argue that greater ambiguity increases the extent to which actors and audiences must search inwardly (e.g., mental schema, past experience) or outwardly (e.g., social norms) for cues on how to behave or evaluate a situation and thereby widens the door for gender/sex-linked influences. Correspondingly, we propose that gender/sex effects on behavior and evaluations in these domains will be more likely when gender/sex is more relevant and salient to the setting or task. We propose further that these two situational moderators may work jointly or interactively to influence the likelihood of gender/sex effects in negotiation, risk-taking, and leadership. We conclude by discussing applications of our conceptual framework to psychological science and its translation to practice, including directions for future research.
RESUMO
Rift Valley fever phlebovirus (RVFV) is a zoonotic pathogen that causes Rift Valley fever (RVF) in livestock and humans. Currently, there is no licensed human vaccine or antiviral drug to control RVF. Although multiple species of animals and humans are vulnerable to RVFV infection, host factors affecting susceptibility are not well understood. To identify the host factors or genes essential for RVFV replication, we conducted CRISPR-Cas9 knockout screening in human A549 cells. We then validated the putative genes using siRNA-mediated knock-downs and CRISPR-Cas9-mediated knock-out studies. The role of a candidate gene in the virus replication cycle was assessed by measuring intracellular viral RNA accumulation, and the virus titers were analyzed using plaque assay or TCID50 assay. We identified approximately 900 genes with potential involvement in RVFV infection and replication. Further evaluation of the effect of six genes on viral replication using siRNA-mediated knock-downs revealed that silencing two genes (WDR7 and LRP1) significantly impaired RVFV replication. For further analysis, we focused on the WDR7 gene since the role of the LRP1 gene in RVFV replication was previously described in detail. WDR7 knockout A549 cell lines were generated and used to dissect the effect of WRD7 on a bunyavirus, RVFV, and an orthobunyavirus, La Crosse encephalitis virus (LACV). We observed significant effects of WDR7 knockout cells on both intracellular RVFV RNA levels and viral titers. At the intracellular RNA level, WRD7 affected RVFV replication at a later phase of its replication cycle (24 h) when compared with the LACV replication, which was affected in an earlier replication phase (12 h). In summary, we identified WDR7 as an essential host factor for the replication of two different viruses, RVFV and LACV, both of which belong to the Bunyavirales order. Future studies will investigate the mechanistic role through which WDR7 facilitates phlebovirus replication.
Assuntos
Phlebovirus , Febre do Vale de Rift , Vírus da Febre do Vale do Rift , Animais , Humanos , Vírus da Febre do Vale do Rift/genética , Phlebovirus/genética , Replicação Viral , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia , Proteínas Adaptadoras de Transdução de SinalRESUMO
Background: Rift Valley fever phlebovirus (RVFV) is a zoonotic pathogen that causes Rift Valley fever (RVF) in livestock and humans. Currently, there is no licensed human vaccine or antiviral drug to control RVF. Although multiple species of animals and humans are vulnerable to RVFV infection, host factors affecting susceptibility are not well understood. Methodology: To identify the host factors or genes essential for RVFV replication, we conducted a CRISPR-Cas9 knock-out screen in human A549 cells. We then validated the putative genes using siRNA-mediated knockdowns and CRISPR-Cas9-mediated knockout studies, respectively. The role of a candidate gene in the virus replication cycle was assessed by measuring intracellular viral RNA accumulation, and the virus titers by plaque assay or TCID50 assay. Findings: We identified approximately 900 genes with potential involvement in RVFV infection and replication. Further evaluation of the effect of six genes on viral replication using siRNA-mediated knockdowns found that silencing two genes (WDR7 and LRP1) significantly impaired RVFV replication. For further analysis, we focused on the WDR7 gene since the role of LRP1 in RVFV replication was previously described in detail. Knock-out A549 cell lines were generated and used to dissect the effect of WRD7 on RVFV and another bunyavirus, La Crosse encephalitis virus (LACV). We observed significant effects of WDR7 knock-out cells on both intracellular RVFV RNA levels and viral titers. At the intracellular RNA level, WRD7 affected RVFV replication at a later phase of its replication cycle (24h) when compared to LACV which was affected an earlier replication phase (12h). Conclusion: In summary, we have identified WDR7 as an essential host factor for the replication of two relevant bunyaviruses, RVFV and LACV. Future studies will investigate the mechanistic role by which WDR7 facilitates Phlebovirus replication.
RESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spreads efficiently by spike-mediated, direct cell-to-cell transmission. However, the underlying mechanism is poorly understood. Herein, we demonstrate that the tight junction protein occludin (OCLN) is critical to this process. SARS-CoV-2 infection alters OCLN distribution and expression and causes syncytium formation that leads to viral spread. OCLN knockdown fails to alter SARS-CoV-2 binding but significantly lowers internalization, syncytium formation, and transmission. OCLN overexpression also has no effect on virus binding but enhances virus internalization, cell-to-cell transmission, and replication. OCLN directly interacts with the SARS-CoV-2 spike, and the endosomal entry pathway is involved in OCLN-mediated cell-to-cell fusion rather than in the cell surface entry pathway. All SARS-CoV-2 strains tested (prototypic, alpha, beta, gamma, delta, kappa, and omicron) are dependent on OCLN for cell-to-cell transmission, although the extent of syncytium formation differs between strains. We conclude that SARS-CoV-2 utilizes OCLN as an internalization factor for cell-to-cell transmission.
Assuntos
COVID-19 , Ocludina , Proteínas de Junções Íntimas , Internalização do Vírus , Humanos , Ocludina/genética , Ocludina/metabolismo , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
BACKGROUND: SARS-CoV-2 infection in term placenta is rare. However, growing evidence suggests that susceptibility of the human placenta to infection may vary by gestational age and pathogen. For several viral infections, susceptibility appears to be greatest during early gestation. Peri-implantation placental infections that result in pre-clinical pregnancy loss would typically go undetected. Little is known about the effects of SARS-CoV-2 on the peri-implantation human placenta since this time in pregnancy can only be modeled in vitro. METHODS: We used a human embryonic stem cell (hESC)-derived model of peri-implantation placental development to assess patterns of ACE2 and TMPRSS2 transcription and protein expression in primitive trophoblast. We then infected the same trophoblast cell model with a clinical isolate of SARS-CoV-2 and documented infection dynamics. RESULTS: ACE2 and TMPRSS2 were transcribed and translated in hESC-derived trophoblast, with preferential expression in syncytialized cells. These same cells supported replicative and persistent infection by SARS-CoV-2, while non-syncytialized trophoblast cells in the same cultures did not. CONCLUSIONS: Co-expression of ACE2 and TMPRSS2 in hESC-derived trophoblast and the robust and replicative infection limited to syncytiotrophoblast equivalents support the hypothesis that increased viral susceptibility may be a defining characteristic of primitive trophoblast.
Assuntos
COVID-19/diagnóstico , Placenta/metabolismo , Complicações Infecciosas na Gravidez/virologia , Aborto Espontâneo/virologia , Adulto , Enzima de Conversão de Angiotensina 2 , COVID-19/sangue , Feminino , Humanos , Infecção Persistente , Gravidez , Fatores de Risco , SARS-CoV-2 , Serina Endopeptidases , TrofoblastosRESUMO
Eleven experiments provide evidence that people have a tendency to "shoot the messenger," deeming innocent bearers of bad news unlikeable. In a preregistered lab experiment, participants rated messengers who delivered bad news from a random drawing as relatively unlikeable (Study 1). A second set of studies points to the specificity of the effect: Study 2A shows that it is unique to the (innocent) messenger, and not mere bystanders. Study 2B shows that it is distinct from merely receiving information with which one disagrees. We suggest that people's tendency to deem bearers of bad news as unlikeable stems in part from their desire to make sense of chance processes. Consistent with this account, receiving bad news activates the desire to sense-make (Study 3A), and in turn, activating this desire enhances the tendency to dislike bearers of bad news (Study 3B). Next, stemming from the idea that unexpected outcomes heighten the desire to sense-make, Study 4 shows that when bad news is unexpected, messenger dislike is pronounced. Finally, consistent with the notion that people fulfill the desire to sense-make by attributing agency to entities adjacent to chance events, messenger dislike is correlated with the erroneous belief that the messenger had malevolent motives (Studies 5A, 5B, and 5C). Studies 6A and 6B go further, manipulating messenger motives independently from news valence to suggest their causal role in our process account: the tendency to dislike bearers of bad news is mitigated when recipients are made aware of the benevolence of the messenger's motives. (PsycINFO Database Record (c) 2019 APA, all rights reserved).
Assuntos
Comunicação , Julgamento , Revelação da Verdade , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
Self-regulated learning has been a widely researched subject for decades in educational psychology. Different instruments have been developed to understand learners' self-regulated learning in a specific subject domain. This study developed a measurement scale to assess English-as-a-foreign-language learners' self-regulatory capacity in English language learning and further examined the effects of gender on English-as-a-foreign-language learners' self-regulatory capacity. A series of psychometric analyses including exploratory factor analysis, confirmatory factor analysis, and full structural equation modeling were undertaken to answer the research questions raised. The findings suggest that the scale can attain high reliability and strong validity in two different samplings, and the underlying construct of self-regulation in English language learning is shown to be multidimensional with a significant impact by gender. Theoretical and pedagogical implications are further put forward in light of the research findings.
Assuntos
Comportamento do Adolescente/psicologia , Aprendizagem/fisiologia , Multilinguismo , Testes Psicológicos/normas , Psicometria/instrumentação , Autocontrole/psicologia , Adolescente , Análise Fatorial , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , TaiwanRESUMO
OBJECTIVES: To examine sociodemographic status, psychosocial concerns, and structural barriers associated with women's participation in the USDA's Women, Infants, and Children (WIC) program among those eligible for the program. DESIGN AND SAMPLE: A total of 1,634 White, African-American, Hispanic, and Asian/Pacific Islander (A/PI) women from the New York City area completed the Pregnancy Risk Assessment Monitoring System (PRAMS) from 2004 to 2007, a population-based survey. MEASURES: Data on WIC eligibility and participation, sociodemographic details, unintended pregnancy, social support, and structural barriers were evaluated. RESULTS: Hispanics and Blacks were 4.1 and 2.4 times more likely to participate, respectively, in the WIC program relative to Whites. Mothers reporting unplanned pregnancies, fewer social supports, and more structural barriers (e.g., transportation) were less likely to participate in WIC. Race-stratified analyses revealed race/ethnic differences in the pattern of barriers; unintended pregnancy and structural problems were barriers associated with WIC participation particularly for A/PI. CONCLUSIONS: WIC-eligible women with unintended pregnancies and fewer social supports tend to participate in WIC, but those who experience more structural barriers are less likely to participate. A/PI women may face specific challenges to WIC participation. Careful attention is needed to understand the unique attitudes and behaviors in the process of participating in WIC.