Host range, transmissibility and antigenicity of a pangolin coronavirus

The pathogenic and cross-species transmission potential of SARS-CoV-2-related coronaviruses (CoVs) remain poorly characterized. Here we recovered a wild-type pangolin (Pg) CoV GD strain including derivatives encoding reporter genes using reverse genetics. In primary human cells, PgCoV replicated efficiently but with reduced fitness and showed less efficient transmission via airborne route compared with SARS-CoV-2 in hamsters. PgCoV was potently inhibited by US Food and Drug Administration approved drugs, and neutralized by COVID-19 patient sera and SARS-CoV-2 therapeutic antibodies in vitro. A pan-Sarbecovirus antibody and SARS-CoV-2 S2P recombinant protein vaccine protected BALB/c mice from PgCoV infection. In K18-hACE2 mice, PgCoV infection caused severe clinical disease, but mice were protected by a SARS-CoV-2 human antibody. Efficient PgCoV replication in primary human cells and hACE2 mice, coupled with a capacity for airborne spread, highlights an emergence potential. However, low competitive fitness, pre-immune humans and the benefit of COVID-19 countermeasures should impede its ability to spread globally in human populations.

Regionally distinct progenitor cells in the lower airway give rise to neuroendocrine and multiciliated cells in the developing human lung

Using scRNA-seq and microscopy, we describe a cell that is enriched in the lower airways of the developing human lung and identified by the unique coexpression of SCGB3A2/SFTPB/CFTR. To functionally interrogate these cells, we apply a single-cell barcode-based lineage tracing method, called CellTagging, to track the fate of SCGB3A2/SFTPB/CFTR cells during airway organoid differentiation in vitro. Lineage tracing reveals that these cells have a distinct differentiation potential from basal cells, giving rise predominantly to pulmonary neuroendocrine cells and a subset of multiciliated cells distinguished by high C6 and low MUC16 expression. Lineage tracing results are supported by studies using organoids and isolated cells from the lower noncartilaginous airway. We conclude that SCGB3A2/SFTPB/CFTR cells are enriched in the lower airways of the developing human lung and contribute to the epithelial diversity and heterogeneity in this region.

Allergic Asthma Responses Are Dependent on Macrophage Ontogeny

The ontogenetic composition of tissue-resident macrophages following injury, environmental exposure, or experimental depletion can be altered upon re-establishment of homeostasis. However, the impact of altered resident macrophage ontogenetic milieu on subsequent immune responses is poorly understood. Hence, we assessed the effect of macrophage ontogeny alteration following return to homeostasis on subsequent allergic airway responses to house dust mites (HDM). Using lineage tracing, we confirmed alveolar and interstitial macrophage ontogeny and their replacement by bone marrow-derived macrophages following LPS exposure. This alteration in macrophage ontogenetic milieu reduced allergic airway responses to HDM challenge. In addition, we defined a distinct population of resident-derived interstitial macrophages expressing allergic airway disease genes, located adjacent to terminal bronchi, and reduced by prior LPS exposure. These findings support that the ontogenetic milieu of pulmonary macrophages is a central factor in allergic airway responses and has implications for how prior environmental exposures impact subsequent immune responses and the development of allergy.

SARS-CoV-2 Reverse Genetics Reveals a Variable Infection Gradient in the Respiratory Tract

The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.

SARS-CoV-2 Reverse Genetics Reveals a Variable Infection Gradient in the Respiratory Tract

The mode of acquisition and causes for the variable clinical spectrum of coronavirus disease 2019 (COVID-19) remain unknown. We utilized a reverse genetics system to generate a GFP reporter virus to explore severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogenesis and a luciferase reporter virus to demonstrate sera collected from SARS and COVID-19 patients exhibited limited cross-CoV neutralization. High-sensitivity RNA in situ mapping revealed the highest angiotensin-converting enzyme 2 (ACE2) expression in the nose with decreasing expression throughout the lower respiratory tract, paralleled by a striking gradient of SARS-CoV-2 infection in proximal (high) versus distal (low) pulmonary epithelial cultures. COVID-19 autopsied lung studies identified focal disease and, congruent with culture data, SARS-CoV-2-infected ciliated and type 2 pneumocyte cells in airway and alveolar regions, respectively. These findings highlight the nasal susceptibility to SARS-CoV-2 with likely subsequent aspiration-mediated virus seeding to the lung in SARS-CoV-2 pathogenesis. These reagents provide a foundation for investigations into virus-host interactions in protective immunity, host susceptibility, and virus pathogenesis.

A Conserved Distal Lung Regenerative Pathway in Acute Lung Injury

Improved tools have led to a burgeoning understanding of lung regeneration in mice, but it is not yet known how these insights may be relevant to acute lung injury in humans. We report in detail two cases of fulminant idiopathic acute lung injury requiring extracorporeal membrane oxygenation in previously healthy young adults with acute respiratory distress syndrome, one of whom required lung transplantation. Biopsy specimens showed diffuse alveolar injury with a striking paucity of alveolar epithelial regeneration, rare hyaline membranes, and diffuse contiguous airspace lining by macrophages. This novel constellation was termed diffuse alveolar injury with delayed epithelization. In addition, mirroring data from murine models of lung injury/regeneration, peribronchiolar basaloid pods (previously described as squamous metaplasia) and ciliated bronchiolarization were identified in these patients and in 39% of 57 historical cases with diffuse alveolar damage. These findings demonstrate a common and clinically relevant human disease correlate for murine models of severe acute lung injury. Evidence suggests that peribronchiolar basaloid pods and bronchiolarization are related spatially and temporally and likely represent overlapping sequential stages of the response to severe distal airway injury.

ACTL6A Is Co-Amplified with p63 in Squamous Cell Carcinoma to Drive YAP Activation, Regenerative Proliferation, and Poor Prognosis

Loss-of-function mutations in SWI/SNF chromatin-remodeling subunit genes are observed in many cancers, but an oncogenic role for SWI/SNF is not well established. Here, we reveal that ACTL6A, encoding an SWI/SNF subunit linked to stem cell and progenitor cell function, is frequently co-amplified and highly expressed together with the p53 family member p63 in head and neck squamous cell carcinoma (HNSCC). ACTL6A and p63 physically interact, cooperatively controlling a transcriptional program that promotes proliferation and suppresses differentiation, in part through activation of the Hippo-YAP pathway via regulators including WWC1. Ectopic ACTL6A/p63 expression promotes tumorigenesis, while ACTL6A expression and YAP activation are highly correlated in primary HNSCC and predict poor patient survival. Thus, ACTL6A and p63 collaborate as oncogenic drivers in HNSCC.

Identification of a novel epigenetic regulatory region within the pluripotency associated microRNA cluster, EEmiRC

The miR-290 cluster is expressed in embryonic stem cells (ESCs) and is important for the maintenance of pluripotency, but little is known about the mechanisms regulating the early embryonic microRNA cluster (EEmiRC) expression. Here we report the identification of a 332-bp intragenic enhancer (IE) able to modulate the transcription of the mouse EEmiRC locus, presumably through binding of transcription modulators like Oct3/4, Sox2 and CTCF. This IE also contains a CpG island showing a differential pattern of DNA and histone methylation marks during differentiation of ESCs, which places EEmiRC in a novel regulatory feedback loop with DNA methylases. Deletion of IE significantly reduced the transcription of the EEmiRC, further proving the importance of this region in regulating the expression of EEmiRC.

Attentional bias in obsessional compulsive disorder

To date, studies of information processing in anxiety disorders have suggested that the latter are characterised by vigilance for threatening stimuli, possibly specific to personally relevant threat content. The present study represents an attempt to establish whether patients suffering from Obsessional Compulsive Disorder (OCD), generally classified as an anxiety disorder, show a similar cognitive bias. Thus, a replication of MacLeod, Mathews and Tata's (1986) study [Journal of Abnormal Psychology, 95, 15-20] is reported, employing modified materials of direct concern to the OCD subjects i.e. Contamination-related words. The results did indeed reveal content specific vigilance, whereby the OCD group were more vigilant for contamination content than mood-matched High Trait Anxious (HTA) controls, but the reverse was true for Social Anxiety words. Additionally, while a general threat interference effect was identified for both OCD and HTA subjects this was not content specific. A second experiment employing Low Trait Anxious subjects revealed no vigilance for threat nor any threat interference in this sample. The clinical implications and possible mechanism underlying these results are discussed.

Lack of cognitive recovery following withdrawal from long-term benzodiazepine use

Twenty-one patients with significant long-term therapeutic benzodiazepine (BZ) use, who remained abstinent at 6 months follow-up after successfully completing a standardized inpatient BZ withdrawal regime, and 21 normal controls matched for age and IQ but not for anxiety, were repeatedly tested on a simple battery of routine psychometric tests of cognitive function, pre- and post-withdrawal and at 6 months follow-up. The results demonstrated significant impairment in patients in verbal learning and memory, psychomotor, visuo-motor and visuo-conceptual abilities, compared with controls, at all three time points. Despite practice effects, no evidence of immediate recovery of cognitive function following BZ withdrawal was found. Modest recovery of certain deficits emerged at 6 months follow-up in the BZ group, but this remained significantly below the equivalent control performance. The implications of persisting cognitive deficits after withdrawal from long-term BZ use are discussed.

Violent behaviour and interpretative bias: an experimental study of the resolution of ambiguity in violent offenders

The present study used an information-processing approach to investigate differences in interpretation of sentences which were ambiguous for violent or neutral meaning across three groups of subjects: violent offenders, non-violent offender controls and a group of non-offender controls. Subjects were presented with unambiguous and ambiguous sentences. The ambiguous sentences were selected so that they could be interpreted in either a threatening or neutral manner. A recognition memory test indicated that both offender groups were more likely to interpret violent ambiguous sentences in a threatening fashion, with the opposite being shown by the non-offender group. This difference was found to be significant. A control condition suggested that the interpretative bias was specific to violent material and not a general anxiety response. Furthermore, the tendency to infer violent threat was found to correlate with hostility. The results are discussed in relation to cognitive theories of anger and aggression.

Different "types" of cigarette smokers received similar effects from smoking

In experiments with 22 women and with 26 men subjects, contrasted groups of so-called high-arousal situation smokers and low-arousal situation smokers did not differ in the increases in pulse rate and in letter cancellation speed shown after smoking the first cigarette of the day in a prescribed manner. Some implications are discussed.