The structural role of SARS-CoV-2 genetic background in the emergence and success of spike mutations: the case of the spike A222V mutation

The S:A222V point mutation, within the G clade, was characteristic of the 20E (EU1) SARS-CoV-2 variant identified in Spain in early summer 2020. This mutation has now reappeared in the Delta subvariant AY.4.2, raising questions about its specific effect on viral infection. We report combined serological, functional, structural and computational studies characterizing the impact of this mutation. Our results reveal that S:A222V promotes an increased RBD opening and slightly increases ACE2 binding as compared to the parent S:D614G clade. Finally, S:A222V does not reduce sera neutralization capacity, suggesting it does not affect vaccine effectiveness.

Delayed Neurological Improvement After Full Endovascular Reperfusion in Acute Anterior Circulation Ischemic Stroke.

Background and Purpose: We aimed to determine the prevalence and predictors of delayed neurological improvement (DNI) after complete endovascular reperfusion in anterior circulation acute ischemic stroke (AIS). Methods: Retrospective analysis of an online multicenter prospective reperfusion registry of patients with consecutive anterior circulation AIS treated with endovascular thrombectomy (EVT) from January 2018 to June 2019 in tertiary stroke centers of the NORDICTUS (NORD-Spain Network for Research and Innovation in ICTUS) network. We included patients with AIS with a proximal occlusion in whom a modified Thrombolysis in Cerebral Infarction 3 reperfusion pattern was obtained. DNI was defined if, despite absence of early neurological improvement during the first 24 hours, patients achieved functional independence on day 90. Clinical and radiological variables obtained before EVT were analyzed as potential predictors of DNI. Results: Of 1565 patients with consecutive AIS treated with EVT, 1381 had proximal anterior circulation occlusions, 803 (58%) of whom achieved a modified Thrombolysis in Cerebral Infarction 3. Of these, 628 patients fulfilled all selection criteria and were included in the study. Mean age was 73.8 years, 323 (51.4%) were female, and median baseline National Institutes of Health Stroke Scale was 16. Absence of early neurological improvement was observed in 142 (22.6%) patients; 32 of these (22.5%) achieved good long-term outcome and constitute the DNI group. Predictors of DNI in multivariable-adjusted logistic regression were male sex (odds ratio, 6.4 [95% CI, 2.1­22.3] P=0.002), lower pre-EVT National Institutes of Health Stroke Scale score (odds ratio, 1.4 [95% CI, 1.2­1.5], P<0.001), and intravenous thrombolysis (odds ratio, 9.1 [95% CI, 2.7­30.90], P<0.001). Conclusions: One-quarter of patients with anterior circulation AIS who do not clinically improve within the first 24 hours after complete cerebral endovascular recanalization will achieve long-term functional independence, regardless of the poor early clinical course. Male sex, lower initial clinical severity, and use of intravenous thrombolysis before EVT predicted this clinical pattern.

Identification of NPC1 as a novel SARS-CoV-2 intracellular target

Niemann-Pick type C1 (NPC1) receptor is an endosomal membrane protein that regulates intracellular cholesterol trafficking, which is crucial in the Ebola virus (EBOV) cycle. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the cell by binding of the viral spike (S) protein to the ACE2 receptor. This requires S-protein processing either by the surface transmembrane serine protease TMPRSS2 for plasma membrane fusion or cathepsin L for endosomal entry. Additional host factors are required for viral fusion at endosomes. Here, we report a novel interaction of the SARS-CoV-2 nucleoprotein (N) with the cholesterol transporter NPC1. Moreover, small molecules interfering with NPC1 that inhibit EBOV entry, also inhibited human coronavirus. Our findings suggest an important role for NPC1 in SARS-CoV-2 infection, a common strategy shared with EBOV, and a potential therapeutic target to fight against COVID-19.

Host-directed FDA-approved drugs with antiviral activity against SARS-CoV-2 identified by hierarchical in silico/in vitro screening methods

The unprecedent situation generated by the COVID-19 global emergency prompted us to actively work to fight against this pandemic by searching for repurposable agents among FDA approved drugs to shed light into immediate opportunities for the treatment of COVID-19 patients. In the attempt to proceed toward a proper rationalization of the search for new antivirals among approved drugs, we carried out a hierarchical in silico/in vitro protocol which successfully combines virtual and biological screening to speed up the identification of host-directed therapies against COVID-19 in an effective way. To this end a multi-target virtual screening approach focused on host-based targets related to viral entry followed by the experimental evaluation of the antiviral activity of selected compounds has been carried out. As a result, five different potentially repurposable drugs interfering with viral entry, cepharantine, clofazimine, metergoline, imatinib and efloxate, have been identified.

Antibodies as biomarker candidates for response and survival to checkpoint inhibitors in melanoma patients.

BACKGROUND: Long-term survival of stage IV melanoma patients has improved significantly with the development of immune checkpoint inhibitors (CIs). Reliable biomarkers to predict response and clinical outcome are needed. METHODS: We investigated the role of melanoma-associated antibodies as predictive markers for CI therapy in two independent cohorts. In cohort 1, a prospective study, we measured specific antibodies before treatment, after one week and after six to nine weeks of treatment. Cohort 2 consisted of serum samples prior to CI therapy initiation. ELISA assays were performed to quantify specific IgG directed against melanocyte differentiation antigens tyrosinase-related proteins 1 and 2 (TRP1/TYRP1 and TRP2/TYRP2), glycoprotein 100 (gp100), MelanA/MART1, and the cancer-testis antigen NY-ESO-1. Response was defined as either complete or partial remission on CT scan according to RECIST 1.1. RESULTS: In cohort 1, baseline levels of these antibodies were higher in the responder group, although statistical significance was only reached for NY-ESO-1 (p = 0.007). In cohort 2, significantly higher antibody baseline levels for MelanA/MART1 (p = 0.003) and gp100 (p = 0.029) were found. After pooling the results from both cohorts, higher levels of MelanA/MART1 (p = 0.013), TRP1/TYRP1 (p = 0.048), TRP2/TYRP2 (p = 0.047) and NY-ESO-1 (p = 0.005) specific antibodies at baseline were independently associated with response. CONCLUSIONS: Melanoma-associated antibodies may be candidate biomarkers for response and survival in metastatic melanoma patients being treated with CIs. These markers may be used to complement patient assessment, in combination with PD-L1 status, tumor-infiltrating lymphocytes and tumor mutational burden, with the aim to predict outcome of CI treatment in patients with metastatic melanoma. TRIAL REGISTRATION: Ethikkommission Ostschweiz, EKOS 16/079 https://ongoingprojects.swissethics.ch/runningProjects_list.php?q=%28BASECID~contains~2016-00998%29&orderby=dBASECID .

Intracellular silver accumulation in Chlamydomonas reinhardtii upon exposure to carbonate coated silver nanoparticles and silver nitrate.

The intracellular silver accumulation ({Ag}(in)) upon exposure to carbonate coated silver nanoparticles (AgNP, 0.5-10 µM, average diameter 29 nm) and silver nitrate (20-500 nM) was examined in the wild type and in the cell wall free mutant of the green alga Chlamydomonas reinhardtii at pH 7.5. The {Ag}(in) was measured over time up to 1 h after a wash procedure to remove silver ions (Ag(+)) and AgNP from the algal cell surface. The {Ag}(in) increased with increasing exposure time and with increasing AgNP and AgNO(3) concentrations in the exposure media, reaching steady-state concentrations between 10(-5) and 10(-3) mol L(cell)(-1). According to estimated kinetic parameters, high Ag(+) bioconcentration factors were calculated (>10(3) L L(cell)(-1)). Higher accumulation rate constants were assessed in the cell wall free mutant, indicating a protective role of the cell wall in limiting Ag(+) uptake. The bioavailability of AgNP was calculated to be low in both strains relative to Ag(+), suggesting that AgNP internalization across the cell membrane was limited.

Familial presentation of occupational hypersensitivity pneumonitis caused by aspergillus-contaminated esparto dust.

Esparto grass (Stipa tenacissima), which is commonly found in the Mediterranean area, has a wide variety of uses. Five plaster workers from the same family developed cough, dyspnea, malaise, and fever after exposure to the esparto fiber used in their work for the previous few years. They showed a significant decrease in symptoms when away from work. Precipitating antibodies against an esparto extract were found in the sera of all patients. Specific IgG antibodies against Aspergillus fumigatus were detected. A. fumigatus was identified after microbiologic evaluation of esparto fiber samples. The dust derived from fungi-contaminated esparto fibers can cause hypersensitivity pneumonitis in exposed subjects. The causative antigen is A. fumigatus. When esparto fibers were strongly contaminated by fungi, all the workers developed a clinical picture compatible with hypersensitivity pneumonitis. The coincidental finding of an occupational and a familiar condition is unusual.

Familiar presentation of occupational hypersensitivity pneumonitis caused by aspergillus-contaminated esparto dust

Esparto grass (Stipa tenacissima), which is commonly found in the Mediterranean area, has a wide variety of uses. Five plaster workers from the same family developed cough, dyspnea, malaise, and fever after exposure to the esparto fiber used in their work for the previous few years. They showed a significant decrease in symptoms when away from work. Precipitating antibodies against an esparto extract were found in the sera of all patients. Specific IgG antibodies against Aspergillus fumigatus were detected. A. fumigatus was identified after microbiologic evaluation of esparto fiber samples. The dust derived from fungi-contaminated esparto fibers can cause hypersensitivity pneumonitis in exposed subjects. The causative antigen is A. fumigatus. When esparto fibers were strongly contaminated by fungi, all the workers developed a clinical picture compatible with hypersensitivity pneumonitis. The coincidental finding of an occupational and a familiar condition is unusual (AU)

La planta de esparto (Stipa tenacissima), habitual en la región mediterránea, tiene una amplia variedad de usos. Cinco escayolistas de la misma familia presentaron tos, disnea, malestar y fiebre después de la exposición a la fibra de esparto utilizada en su trabajo en los últimos años. Estos pacientes experimentaron una disminución significativa de los síntomas cuando dejaron el trabajo. Se descubrieron anticuerpos precipitantes contra un extracto de esparto en el suero de todos los pacientes. Se detectaron anticuerpos IgG específicos contra Aspergillus fumigatus. Se pudo identificar Aspergillus fumigatus después de la evaluación microbiológica de las muestras de fibra de esparto. El polvo derivado de fibras de esparto contaminadas por hongos puede causar neumonitis por hipersensibilidad en sujetos expuestos. Aspergillus fumigatus es el antígeno responsable. Cuando las fibras de esparto están muy contaminadas por hongos, todos los trabajadores pueden sufrir un cuadro clínico compatible con neumonitis por hipersensibilidad. En este artículo, la peculiaridad es el hallazgo concurrente de un proceso familiar y laboral (AU)