Molecular basis of convergent evolution of ACE2 receptor utilization among HKU5 coronaviruses.

DPP4 was considered a canonical receptor for merbecoviruses until the recent discovery of African bat-borne MERS-related coronaviruses using ACE2. The extent and diversity with which merbecoviruses engage ACE2 and their receptor species tropism remain unknown. Here, we reveal that HKU5 enters host cells utilizing Pipistrellus abramus (P.abr) and several non-bat mammalian ACE2s through a binding mode distinct from that of any other known ACE2-using coronaviruses. These results show that several merbecovirus clades independently evolved ACE2 utilization, which appears to be a broadly shared property among these pathogens, through an extraordinary diversity of ACE2 recognition modes. We show that MERS-CoV and HKU5 have markedly distinct antigenicity, due to extensive genetic divergence, and identified several HKU5 inhibitors, including two clinical compounds. Our findings profoundly alter our understanding of coronavirus evolution and pave the way for developing countermeasures against viruses poised for human emergence.

Mapping immunodominant sites on the MERS-CoV spike glycoprotein targeted by infection-elicited antibodies in humans.

Middle East respiratory syndrome coronavirus (MERS-CoV) first emerged in 2012 and causes human infections in endemic regions. Vaccines and therapeutics in development against MERS-CoV focus on the spike (S) glycoprotein to prevent viral entry into target cells. These efforts are limited by a poor understanding of antibody responses elicited by infection. Here, we analyze S-directed antibody responses in plasma collected from MERS-CoV-infected individuals. We observe that binding and neutralizing antibodies peak 1-6 weeks after symptom onset/hospitalization, persist for at least 6 months, and neutralize human and camel MERS-CoV strains. We show that the MERS-CoV S1 subunit is immunodominant and that antibodies targeting S1, particularly the receptor-binding domain (RBD), account for most plasma neutralizing activity. Antigenic site mapping reveals that plasma antibodies frequently target RBD epitopes, whereas targeting of S2 subunit epitopes is rare. Our data reveal the humoral immune responses elicited by MERS-CoV infection, which will guide vaccine and therapeutic design.

Spike deep mutational scanning helps predict success of SARS-CoV-2 clades.

SARS-CoV-2 variants acquire mutations in the spike protein that promote immune evasion1 and affect other properties that contribute to viral fitness, such as ACE2 receptor binding and cell entry2,3. Knowledge of how mutations affect these spike phenotypes can provide insight into the current and potential future evolution of the virus. Here we use pseudovirus deep mutational scanning4 to measure how more than 9,000 mutations across the full XBB.1.5 and BA.2 spikes affect ACE2 binding, cell entry or escape from human sera. We find that mutations outside the receptor-binding domain (RBD) have meaningfully affected ACE2 binding during SARS-CoV-2 evolution. We also measure how mutations to the XBB.1.5 spike affect neutralization by serum from individuals who recently had SARS-CoV-2 infections. The strongest serum escape mutations are in the RBD at sites 357, 420, 440, 456 and 473; however, the antigenic effects of these mutations vary across individuals. We also identify strong escape mutations outside the RBD; however, many of them decrease ACE2 binding, suggesting they act by modulating RBD conformation. Notably, the growth rates of human SARS-CoV-2 clades can be explained in substantial part by the measured effects of mutations on spike phenotypes, suggesting our data could enable better prediction of viral evolution.

Addressing the consequences of the corporatization of reproductive medicine.

In Australia and the UK, commercialization and corporatization of assisted reproductive technologies have created a marketplace of clinics, products, and services. While this has arguably increased choice for patients, 'choice', shaped by commercial imperatives may not mean better-quality care. At present, regulation of clinics (including clinic-corporations) and clinicians focuses on the doctor-patient dyad and the clinic-consumer dyad. Scant attention has been paid to the conflicts between the clinic-corporation's duty to its shareholders and investors, the medical profession's duty to the corporations within which they practice, and the obligations of both clinicians and corporations to patients and to health systems. Frameworks of regulation based in corporate governance and business ethics, such as stakeholder models and 'corporate social responsibility', have well-recognized limits and may not translate well into healthcare settings. This means that existing governance frameworks may not meet the needs of patients or health systems. We argue for the development of novel regulatory approaches that more explicitly characterize the obligations that both corporations and clinicians in corporate environments have to patients and to society, and that promote fulfilment of these obligations. We consider mechanisms for application in the multi-jurisdictional setting of Australia, and the single jurisdictional settings of the UK.

Human coronavirus HKU1 recognition of the TMPRSS2 host receptor.

The human coronavirus HKU1 spike (S) glycoprotein engages host cell surface sialoglycans and transmembrane protease serine 2 (TMPRSS2) to initiate infection. The molecular basis of HKU1 binding to TMPRSS2 and determinants of host receptor tropism remain elusive. We designed an active human TMPRSS2 construct enabling high-yield recombinant production in human cells of this key therapeutic target. We determined a cryo-electron microscopy structure of the HKU1 RBD bound to human TMPRSS2, providing a blueprint of the interactions supporting viral entry and explaining the specificity for TMPRSS2 among orthologous proteases. We identified TMPRSS2 orthologs from five mammalian orders promoting HKU1 S-mediated entry into cells along with key residues governing host receptor usage. Our data show that the TMPRSS2 binding motif is a site of vulnerability to neutralizing antibodies and suggest that HKU1 uses S conformational masking and glycan shielding to balance immune evasion and receptor engagement.

A broadly generalizable stabilization strategy for sarbecovirus fusion machinery vaccines.

Evolution of SARS-CoV-2 alters the antigenicity of the immunodominant spike (S) receptor-binding domain and N-terminal domain, undermining the efficacy of vaccines and antibody therapies. To overcome this challenge, we set out to develop a vaccine focusing antibody responses on the highly conserved but metastable S2 subunit, which folds as a spring-loaded fusion machinery. We describe a strategy for prefusion-stabilization and high yield recombinant production of SARS-CoV-2 S2 trimers with native structure and antigenicity. We demonstrate that our design strategy is broadly generalizable to sarbecoviruses, as exemplified with the SARS-CoV-1 (clade 1a) and PRD-0038 (clade 3) S2 subunits. Immunization of mice with a prefusion-stabilized SARS-CoV-2 S2 trimer elicits broadly reactive sarbecovirus antibodies and neutralizing antibody titers of comparable magnitude against Wuhan-Hu-1 and the immune evasive XBB.1.5 variant. Vaccinated mice were protected from weight loss and disease upon challenge with XBB.1.5, providing proof-of-principle for fusion machinery sarbecovirus vaccines.

Money matters: a critique of 'informed financial consent'.

In recent years, concerns about the financial burdens of health care and growing recognition of the relevance of cost to decision making and patient experience have increasingly focused attention on financial 'transparency' and disclosure of costs to patients. In some jurisdictions, there have been calls not only for timely disclosure of costs information, but also for 'informed financial consent'. However, simply putting the 'financial' into 'informed consent' and invoking an informed consent standard for cost information encounters several ethical, legal, and practical difficulties. This article will examine the viability and desirability of 'informed financial consent', and whether it is possible to derive ideas from traditional informed consent that may improve decision making and the patient experience. We argue that, while there are important legal, ethical, and practical challenges to consider, some of the principles of informed consent to treatment can usefully guide financial communication. We also argue that, while medical practitioners (and their delegates) have an important role to play in bridging the gap between disclosure and enabling informed (financial) decision making, this must be part of a multi-faceted approach to financial communication that acknowledges the influence of non-clinical providers and other structural forces on discharging such obligations.

Advanced Antimicrobial and Anti-Infective Strategies to Manage Peri-Implant Infection: A Narrative Review.

Despite reductions in bacterial infection and enhanced success rate, the widespread use of systemic antibiotic prophylaxis in implant dentistry is controversial. This use has contributed to the growing problem of antimicrobial resistance, along with creating significant health and economic burdens. The basic mechanisms that cause implant infection can be targeted by new prevention and treatment methods which can also lead to the reduction of systemic antibiotic exposure and its associated adverse effects. This review aims to summarize advanced biomaterial strategies applied to implant components based on anti-pathogenic mechanisms and immune balance mechanisms. It emphasizes that modifying the dental implant surface and regulating the early immune response are promising strategies, which may further prevent or slow the development of peri-implant infection, and subsequent failure.

Sexual Boundary Violations by Doctors - Context, Regulatory Consequences and Preventive Strategies.

While sexual boundary violations by doctors (SBVs) are viewed with utmost seriousness by disciplinary bodies and tribunals, complaints of SBVs in Australia continue to increase. In 2023, the Australian Health Practitioner Regulation Agency (Ahpra) outlined a "blueprint" to protect patients better from sexual misconduct in healthcare: reform being considered in 2024, by Australian health ministers. Few analyses or studies have offered an overview of the prevalence, effects, and causes of SBVs, nor the duties, liabilities, possible disciplinary action against, and potential treatment of, doctors who commit them. This column offers such an overview, and considers, additionally, whether doctors who may have psychiatric disorders associated with their boundary violations would be suitable candidates for treatment. Ultimately, we contend that a purely "responsive" approach is inadequate, and preventive measures such as screening and more effective education should be considered in medical schools as a way of reducing the incidence of SBVs.

The Anatomy Act 1977 (NSW) Dissected: Review and Reform.

This column discusses the Anatomy Act 1977 (NSW) and its regulatory environment. The column begins with examining the history of anatomy regulation in the United Kingdom and Australia. It then goes on to analyse the history of the current anatomy regulation in New South Wales, pointing out areas for reform.

Mapping immunodominant sites on the MERS-CoV spike glycoprotein targeted by infection-elicited antibodies in humans.

Middle-East respiratory syndrome coronavirus (MERS-CoV) first emerged in 2012 and causes human infections in endemic regions. Most vaccines and therapeutics in development against MERS-CoV focus on the spike (S) glycoprotein to prevent viral entry into target cells. These efforts, however, are limited by a poor understanding of antibody responses elicited by infection along with their durability, fine specificity and contribution of distinct S antigenic sites to neutralization. To address this knowledge gap, we analyzed S-directed binding and neutralizing antibody titers in plasma collected from individuals infected with MERS-CoV in 2017-2019 (prior to the COVID-19 pandemic). We observed that binding and neutralizing antibodies peak 1 to 6 weeks after symptom onset/hospitalization, persist for at least 6 months, and broadly neutralize human and camel MERS-CoV strains. We show that the MERS-CoV S1 subunit is immunodominant and that antibodies targeting S1, particularly the RBD, account for most plasma neutralizing activity. Antigenic site mapping revealed that polyclonal plasma antibodies frequently target RBD epitopes, particularly a site exposed irrespective of the S trimer conformation, whereas targeting of S2 subunit epitopes is rare, similar to SARS-CoV-2. Our data reveal in unprecedented details the humoral immune responses elicited by MERS-CoV infection, which will guide vaccine and therapeutic design.

Protein nanoparticle vaccines induce potent neutralizing antibody responses against MERS-CoV.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic betacoronavirus that causes severe and often lethal respiratory illness in humans. The MERS-CoV spike (S) protein is the viral fusogen and the target of neutralizing antibodies, and has therefore been the focus of vaccine design efforts. Currently there are no licensed vaccines against MERS-CoV and only a few candidates have advanced to Phase I clinical trials. Here we developed MERS-CoV vaccines utilizing a computationally designed protein nanoparticle platform that has generated safe and immunogenic vaccines against various enveloped viruses, including a licensed vaccine for SARS-CoV-2. Two-component protein nanoparticles displaying MERS-CoV S-derived antigens induced robust neutralizing antibody responses and protected mice against challenge with mouse-adapted MERS-CoV. Electron microscopy polyclonal epitope mapping and serum competition assays revealed the specificities of the dominant antibody responses elicited by immunogens displaying the prefusion-stabilized S-2P trimer, receptor binding domain (RBD), or N-terminal domain (NTD). An RBD nanoparticle vaccine elicited antibodies targeting multiple non-overlapping epitopes in the RBD, whereas anti-NTD antibodies elicited by the S-2P- and NTD-based immunogens converged on a single antigenic site. Our findings demonstrate the potential of two-component nanoparticle vaccine candidates for MERS-CoV and suggest that this platform technology could be broadly applicable to betacoronavirus vaccine development.

Human coronavirus HKU1 recognition of the TMPRSS2 host receptor.

The human coronavirus HKU1 spike (S) glycoprotein engages host cell surface sialoglycans and transmembrane protease serine 2 (TMPRSS2) to initiate infection. The molecular basis of HKU1 binding to TMPRSS2 and determinants of host receptor tropism remain elusive. Here, we designed an active human TMPRSS2 construct enabling high-yield recombinant production in human cells of this key therapeutic target. We determined a cryo-electron microscopy structure of the HKU1 RBD bound to human TMPRSS2 providing a blueprint of the interactions supporting viral entry and explaining the specificity for TMPRSS2 among human type 2 transmembrane serine proteases. We found that human, rat, hamster and camel TMPRSS2 promote HKU1 S-mediated entry into cells and identified key residues governing host receptor usage. Our data show that serum antibodies targeting the HKU1 RBD TMPRSS2 binding-site are key for neutralization and that HKU1 uses conformational masking and glycan shielding to balance immune evasion and receptor engagement.

The forecasted prevalence of comorbidities and multimorbidity in people with HIV in the United States through the year 2030: A modeling study.

BACKGROUND: Estimating the medical complexity of people aging with HIV can inform clinical programs and policy to meet future healthcare needs. The objective of our study was to forecast the prevalence of comorbidities and multimorbidity among people with HIV (PWH) using antiretroviral therapy (ART) in the United States (US) through 2030. METHODS AND FINDINGS: Using the PEARL model-an agent-based simulation of PWH who have initiated ART in the US-the prevalence of anxiety, depression, stage ≥3 chronic kidney disease (CKD), dyslipidemia, diabetes, hypertension, cancer, end-stage liver disease (ESLD), myocardial infarction (MI), and multimorbidity (≥2 mental or physical comorbidities, other than HIV) were forecasted through 2030. Simulations were informed by the US CDC HIV surveillance data of new HIV diagnosis and the longitudinal North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) data on risk of comorbidities from 2009 to 2017. The simulated population represented 15 subgroups of PWH including Hispanic, non-Hispanic White (White), and non-Hispanic Black/African American (Black/AA) men who have sex with men (MSM), men and women with history of injection drug use and heterosexual men and women. Simulations were replicated for 200 runs and forecasted outcomes are presented as median values (95% uncertainty ranges are presented in the Supporting information). In 2020, PEARL forecasted a median population of 670,000 individuals receiving ART in the US, of whom 9% men and 4% women with history of injection drug use, 60% MSM, 8% heterosexual men, and 19% heterosexual women. Additionally, 44% were Black/AA, 32% White, and 23% Hispanic. Along with a gradual rise in population size of PWH receiving ART-reaching 908,000 individuals by 2030-PEARL forecasted a surge in prevalence of most comorbidities to 2030. Depression and/or anxiety was high and increased from 60% in 2020 to 64% in 2030. Hypertension decreased while dyslipidemia, diabetes, CKD, and MI increased. There was little change in prevalence of cancer and ESLD. The forecasted multimorbidity among PWH receiving ART increased from 63% in 2020 to 70% in 2030. There was heterogeneity in trends across subgroups. Among Black women with history of injection drug use in 2030 (oldest demographic subgroup with median age of 66 year), dyslipidemia, CKD, hypertension, diabetes, anxiety, and depression were most prevalent, with 92% experiencing multimorbidity. Among Black MSM in 2030 (youngest demographic subgroup with median age of 42 year), depression and CKD were highly prevalent, with 57% experiencing multimorbidity. These results are limited by the assumption that trends in new HIV diagnoses, mortality, and comorbidity risk observed in 2009 to 2017 will persist through 2030; influences occurring outside this period are not accounted for in the forecasts. CONCLUSIONS: The PEARL forecasts suggest a continued rise in comorbidity and multimorbidity prevalence to 2030, marked by heterogeneities across race/ethnicity, gender, and HIV acquisition risk subgroups. HIV clinicians must stay current on the ever-changing comorbidities-specific guidelines to provide guideline-recommended care. HIV clinical directors should ensure linkages to subspecialty care within the clinic or by referral. HIV policy decision-makers must allocate resources and support extended clinical capacity to meet the healthcare needs of people aging with HIV.

The Impact of Biologic Therapies on Rate of Colectomy in Paediatric-onset Ulcerative Colitis - A Population-Based Cohort Study.

AIM: Biologic therapies have been associated with reduced rate of colectomy in ulcerative colitis (UC) in adults, but data are limited in paediatric-onset UC. Our aim was to define the rate of colectomy in paediatric-onset UC, including post-transition into adult care, and to evaluate the impact of biologic therapies on rate of colectomy. METHOD: All prevalent patients diagnosed with paediatric-onset UC in South-East Scotland were identified from a prospectively accrued database at our regional tertiary centre. Patients exposed to biologics or surgery were identified and further data collected from health records. Kaplan-Meier analysis was used to calculate cumulative risk of colectomy over time. RESULTS: 145 prevalent patients were identified between 2000 and 2021. Median follow-up was 7.9 years (IQR 4.1-13.1). 23 patients (16 %) underwent a colectomy. 50/145 (34 %) patients received biologic therapy, and 13/23 (57 %) patients who underwent colectomy received biologics. The cumulative risk of colectomy across the whole cohort at 1, 5, and 10 years was 3 %, 13 % and 16 %, respectively. Patients exposed to biologics had a higher colectomy rate at 5 and 10 years (22 % and 34 %). Patients in the pre-biologic era (2000-2008) had non-significantly reduced time from diagnosis to colectomy (2.4 vs 3.7 years, p = 0.204). CONCLUSION: We have defined the 1-, 5-, and 10-year colectomy rate in a population-based cohort of Paediatric-onset UC patients. Patients who received biologic therapy had a significantly increased risk of colectomy. Increased severity of disease in these patients may account for the greater colectomy risk. LEVEL OF EVIDENCE: Level 1.

Full-body skin examination in screening for cutaneous malignancy: a focus on concealed sites and the practices of Australian dermatologists.

BACKGROUND: Full-body skin examination (FSE) is a vital practice in the diagnosis of cutaneous malignancy. Precisely how FSE should be conducted with respect to concealed site inclusion remains poorly elucidated. OBJECTIVE: To establish the approach of Australian dermatologists to concealed site examination (CSE). METHODS: A cross-sectional study was performed consisting of an online self-administered 11-question survey delivered to fellows of the Australasian College of Dermatologists. RESULTS: There were 237 respondents. Anogenitalia was the least often examined concealed site (4.6%), and 59.9, 32.9, and 14.3% reported always examining the scalp, breasts, and oral mucosa, respectively. Patient concern was the most frequently cited factor prompting examination, while many cited low incidence of pathology and limited chaperone availability as the main barriers to routine examination of these sites. CONCLUSION: Most Australian dermatologists do not routinely examine breasts, oral mucosal, or anogenital sites as part of an FSE. Emphasis should be made on identifying individual patient risk factors and education regarding self-examination of sensitive sites. A consensus approach to the conduct of the FSE, including concealed sites, is needed to better delineate clinician responsibilities and address medicolegal implications.

Broad receptor tropism and immunogenicity of a clade 3 sarbecovirus.

Although Rhinolophus bats harbor diverse clade 3 sarbecoviruses, the structural determinants of receptor tropism along with the antigenicity of their spike (S) glycoproteins remain uncharacterized. Here, we show that the African Rhinolophus bat clade 3 sarbecovirus PRD-0038 S has a broad angiotensin-converting enzyme 2 (ACE2) usage and that receptor-binding domain (RBD) mutations further expand receptor promiscuity and enable human ACE2 utilization. We determine a cryo-EM structure of the PRD-0038 RBD bound to Rhinolophus alcyone ACE2, explaining receptor tropism and highlighting differences with SARS-CoV-1 and SARS-CoV-2. Characterization of PRD-0038 S using cryo-EM and monoclonal antibody reactivity reveals its distinct antigenicity relative to SARS-CoV-2 and identifies PRD-0038 cross-neutralizing antibodies for pandemic preparedness. PRD-0038 S vaccination elicits greater titers of antibodies cross-reacting with vaccine-mismatched clade 2 and clade 1a sarbecoviruses compared with SARS-CoV-2 S due to broader antigenic targeting, motivating the inclusion of clade 3 antigens in next-generation vaccines for enhanced resilience to viral evolution.