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The coronavirus spike glycoprotein attaches to host receptors and mediates viral fusion. Using a broad screening approach, we isolated seven monoclonal antibodies (mAbs) that bind to all human-infecting coronavirus spike proteins from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune donors. These mAbs recognize the fusion peptide and acquire affinity and breadth through somatic mutations. Despite targeting a conserved motif, only some mAbs show broad neutralizing activity in vitro against alpha- and betacoronaviruses, including animal coronaviruses WIV-1 and PDF-2180. Two selected mAbs also neutralize Omicron BA.1 and BA.2 authentic viruses and reduce viral burden and pathology in vivo. Structural and functional analyses showed that the fusion peptide-specific mAbs bound with different modalities to a cryptic epitope hidden in prefusion stabilized spike, which became exposed upon binding of angiotensin-converting enzyme 2 (ACE2) or ACE2-mimicking mAbs. ispartof: SCIENCE vol:377 issue:6607 pages:735-741 ispartof: location:United States status: published

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant-neutralizing antibody that is a strong candidate for clinical development. ispartof: SCIENCE vol:378 issue:6620 pages:619-+ ispartof: location:United States status: published

Background & AimsChronic hepatitis B is a major global public health problem, and coinfection with hepatitis delta virus (HDV) worsens disease outcome. Here, we describe a hepatitis B virus (HBV) surface antigen (HBsAg)-targeting monoclonal antibody (mAb) with the potential to promote functional cure of chronic hepatitis B and D to address this unmet medical need.MethodsHBsAg-specific mAbs were isolated from memory B cells of HBV vaccinated individuals. In vitro neutralization was determined against HBV and HDV enveloped with HBsAg representing eight HBV genotypes. Human liver-chimeric mice were treated twice weekly with a candidate mAb starting three weeks post HBV inoculation (spreading phase) or during stable HBV or HBV/HDV coinfection (chronic phase).ResultsFrom a panel of human anti-HBs mAbs, VIR-3434 was selected and engineered for pre-clinical development. VIR-3434 targets a putative conserved, conformational epitope within the antigenic loop of HBsAg and neutralized HBV and HDV infection with >12,000-fold higher potency than Hepatitis B Immunoglobulins in vitro. Neutralization was pan-genotypic against strains representative of HBV genotypes A-H. In the spreading phase of HBV infection in human liver-chimeric mice, a parental mAb of VIR-3434 (HBC34) prevented HBV dissemination and intrahepatic HBV RNA and cccDNA increase. In the chronic phase of HBV infection or co-infection with HDV, HBC34 treatment decreased circulating HBsAg by >1 log and HDV RNA by >2 logs.ConclusionsThis in vitro and in vivo characterization identified the potent anti-HBs mAb VIR-3434, which reduces circulating HBsAg and HBV/HDV viremia in human liver-chimeric mice. VIR-3434 is currently in clinical development for treatment of patients with chronic hepatitis B or D.Lay summaryChronic infection with hepatitis B virus places approximately 290 million individuals worldwide at risk for severe liver disease and cancer. Currently available treatments result in low rates of functional cure or require lifelong therapy that does not eliminate the risk of liver disease. We isolated and characterized a potent, human antibody that neutralizes hepatitis B and D viruses and reduces infection in a mouse model. This antibody could provide a new treatment for patients with chronic hepatitis B and D.HighlightsIdentification of a human mAb VIR-3434 that potently neutralizes HBV and HDVVIR-3434 targets a conserved, conformational epitope of the HBsAg antigenic loopVIR-3434 treatment blocks intrahepatic HBV spread in human liver-chimeric miceVIR-3434 treatment reduces circulating HBsAg and HDV RNA in co-infected miceData have enabled clinical development of VIR-3434 against chronic hepatitis B/D

SARS-CoV-2 infection—which involves both cell attachment and membrane fusion—relies on the angiotensin-converting enzyme 2 (ACE2) receptor, which is paradoxically found at low levels in the respiratory tract1–3, suggesting that there may be additional mechanisms facilitating infection. Here we show that C-type lectin receptors, DC-SIGN, L-SIGN and the sialic acid–binding immunoglobulin-like lectin 1 (SIGLEC1) function as attachment receptors by enhancing ACE2-mediated infection and modulating the neutralizing activity of different classes of spike-specific antibodies. Antibodies to the amino-terminal domain or to the conserved site at the base of the receptor-binding domain, while poorly neutralizing infection of ACE2-overexpressing cells, effectively block lectin-facilitated infection. Conversely, antibodies to the receptor binding motif, while potently neutralizing infection of ACE2-overexpressing cells, poorly neutralize infection of cells expressing DC-SIGN or L-SIGN and trigger fusogenic rearrangement of the spike, promoting cell-to-cell fusion. Collectively, these findings identify a lectin-dependent pathway that enhances ACE2-dependent infection by SARS-CoV-2 and reveal distinct mechanisms of neutralization by different classes of spike-specific antibodies. C-type lectins and SIGLEC1 function as attachment receptors for SARS-CoV-2 and enhance ACE2-mediated infection.

Secretory IgA (SIgA) is the most abundant antibody type in intestinal secretions where it contributes to safeguarding the epithelium from invasive pathogens like the Gram-negative bacterium, Salmonella enterica serovar Typhimurium (STm). For example, we recently reported that passive oral administration of the recombinant monoclonal SIgA antibody, Sal4, to mice promotes STm agglutination in the intestinal lumen and restricts bacterial invasion of Peyer's patch tissues. In this report, we sought to recapitulate Sal4-mediated protection against STm in human Enteroids and human intestinal organoids (HIOs) as models to decipher the molecular mechanisms by which antibodies function in mucosal immunity in the human gastrointestinal tract. We confirm that Enteroids and HIO-derived monolayers are permissive to STm infection, dependent on HilD, the master transcriptional regulator of the SPI-I type three secretion system (T3SS). Stimulation of M-like cells in both Enteroids and HIOs by the addition of RANKL further enhanced STm invasion. The apical addition of Sal4 mouse IgA, as well as recombinant human Sal4 dimeric IgA (dIgA) and SIgA resulted a dose-dependent reduction in bacterial invasion. Moreover, basolateral application of Sal4 dIgA to Enteroid and HIO monolayers gave rise to SIgA in the apical compartment via a pathway dependent on expression of the polymeric immunoglobulin receptor (pIgR). The resulting Sal4 SIgA was sufficient to reduce STm invasion of Enteroid and HIO epithelial cell monolayers by ~20-fold. Recombinant Sal4 IgG was also transported in the Enteroid and HIOs, but to a lesser degree and via a pathway dependent on the neonatal Fc receptor (FCGRT). The models described lay the foundation for future studies into detailed mechanisms of IgA and IgG protection against STm and other pathogens.

Coronaviruses use diverse Spike (S) glycoproteins to attach to host receptors and fuse with target cells. Using a broad screening approach, we isolated from SARS-CoV-2 immune donors seven monoclonal antibodies (mAbs) that bind to all human alpha and beta coronavirus S proteins. These mAbs recognize the fusion peptide and acquire high affinity and breadth through somatic mutations. Despite targeting a conserved motif, only some mAbs show broad neutralizing activity in vitro against alpha and beta coronaviruses, including Omicron BA.1 variant and bat WIV-1, and reduce viral titers and pathology in vivo. Structural and functional analyses show that the fusion peptide-specific mAbs bind with different modalities to a cryptic epitope which is concealed by prefusion-stabilizing ‘2P’ mutations and becomes exposed upon binding of ACE2 or ACE2-mimicking mAbs. This study identifies a new class of pan-coronavirus neutralizing mAbs and reveals a receptor-induced conformational change in the S protein that exposes the fusion peptide region.

Understanding broadly neutralizing sarbecovirus antibody responses is key to developing countermeasures against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and future zoonotic sarbecoviruses. We describe the isolation and characterization of a human monoclonal antibody, designated S2K146, that broadly neutralizes viruses belonging to SARS-CoV– and SARS-CoV-2–related sarbecovirus clades, which use angiotensin-converting enzyme 2 (ACE2) as an entry receptor. Structural and functional studies show that most of the virus residues that directly bind S2K146 are also involved in binding to ACE2. This allows the antibody to potently inhibit receptor attachment. S2K146 protects against SARS-CoV-2 Beta variant challenge in hamsters, and viral passaging experiments reveal a high barrier for emergence of escape mutants, making it a good candidate for clinical development. The conserved ACE2-binding residues present a site of vulnerability that might be leveraged for developing vaccines eliciting broad sarbecovirus immunity.

The spillovers of betacoronaviruses in humans and the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants highlight the need for broad coronavirus countermeasures. We describe five monoclonal antibodies (mAbs) cross-reacting with the stem helix of multiple betacoronavirus spike glycoproteins isolated from COVID-19 convalescent individuals. Using structural and functional studies, we show that the mAb with the greatest breadth (S2P6) neutralizes pseudotyped viruses from three different subgenera through the inhibition of membrane fusion, and we delineate the molecular basis for its cross-reactivity. S2P6 reduces viral burden in hamsters challenged with SARS-CoV-2 through viral neutralization and Fc-mediated effector functions. Stem helix antibodies are rare, oftentimes of narrow specificity, and can acquire neutralization breadth through somatic mutations. These data provide a framework for structure-guided design of pan-betacoronavirus vaccines eliciting broad protection. ispartof: SCIENCE vol:373 issue:6559 pages:1109-1115 ispartof: location:United States status: published

The recent emergence of SARS-CoV-2 variants of concern1-10 and the recurrent spillovers of coronaviruses11,12 into the human population highlight the need for broadly neutralizing antibodies that are not affected by the ongoing antigenic drift and that can prevent or treat future zoonotic infections. Here we describe a human monoclonal antibody designated S2X259, which recognizes a highly conserved cryptic epitope of the receptor-binding domain and cross-reacts with spikes from all clades of sarbecovirus. S2X259 broadly neutralizes spike-mediated cell entry of SARS-CoV-2, including variants of concern (B.1.1.7, B.1.351, P.1, and B.1.427/B.1.429), as well as a wide spectrum of human and potentially zoonotic sarbecoviruses through inhibition of angiotensin-converting enzyme 2 (ACE2) binding to the receptor-binding domain. Furthermore, deep-mutational scanning and in vitro escape selection experiments demonstrate that S2X259 possesses an escape profile that is limited to a single substitution, G504D. We show that prophylactic and therapeutic administration of S2X259 protects Syrian hamsters (Mesocricetus auratus) against challenge with the prototypic SARS-CoV-2 and the B.1.351 variant of concern, which suggests that this monoclonal antibody is a promising candidate for the prevention and treatment of emergent variants and zoonotic infections. Our data reveal a key antigenic site that is targeted by broadly neutralizing antibodies and will guide the design of vaccines that are effective against all sarbecoviruses.

Discovery of new actionable targets and functional networks in melanoma is an urgent need as only a fraction of metastatic patients achieves durable clinical benefit by targeted therapy or immunotherapy approaches. Here we show that NFATc2 expression is associated with an EMT-like transcriptional program and with an invasive melanoma phenotype, as shown by analysis of melanoma cell lines at the mRNA and protein levels, interrogation of the TCGA melanoma dataset and characterization of melanoma lesions by immunohistochemistry. Gene silencing or pharmacological inhibition of NFATc2 downregulated EMT-related genes and AXL, and suppressed c-Myc, FOXM1, and EZH2. Targeting of c-Myc suppressed FOXM1 and EZH2, while targeting of FOXM1 suppressed EZH2. Inhibition of c-Myc, or FOXM1, or EZH2 downregulated EMT-related gene expression, upregulated MITF and suppressed migratory and invasive activity of neoplastic cells. Stable silencing of NFATc2 impaired melanoma cell proliferation in vitro and tumor growth in vivo in SCID mice. In NFATc2+ EZH2+ melanoma cell lines pharmacological co-targeting of NFATc2 and EZH2 exerted strong anti-proliferative and pro-apoptotic activity, irrespective of BRAF or NRAS mutations and of BRAF inhibitor resistance. These results provide preclinical evidence for a role of NFATc2 in shaping the EMT-like melanoma phenotype and reveal a targetable vulnerability associated with NFATc2 and EZH2 expression in melanoma cells belonging to different mutational subsets.

The repeated spillovers of {beta}-coronaviruses in humans along with the rapid emergence of SARS-CoV-2 escape variants highlight the need to develop broad coronavirus therapeutics and vaccines. Five monoclonal antibodies (mAbs) were isolated from COVID-19 convalescent individuals and found to cross-react with multiple {beta}-coronavirus spike (S) glycoproteins by targeting the stem helix. One of these mAbs, S2P6, cross-reacts with more than twenty human and animal {beta}-coronavirus S glycoproteins and broadly neutralizes SARS-CoV-2 and pseudotyped viruses from the sarbecovirus, merbecovirus and embecovirus subgenera. Structural and functional studies delineate the molecular basis of S2P6 cross-reactivity and broad neutralization and indicate that this mAb blocks viral entry by inhibiting membrane fusion. S2P6 protects hamsters challenged with SARS-CoV-2 (including the B.1.351 variant of concern) through direct viral neutralization and Fc-mediated effector functions. Serological and B cell repertoire analyses indicate that antibodies targeting the stem helix are found in some convalescent donors and vaccinees but are predominantly of narrow specificity. Germline reversion of the identified cross-reactive mAbs revealed that their unmutated ancestors are specific for the endemic OC43 or HKU1 viruses and acquired enhanced affinity and breadth through somatic mutations. These data demonstrate that conserved epitopes in the coronavirus fusion machinery can be targeted by protective antibodies and provide a framework for structure-guided design of pan-{beta}-coronavirus vaccines eliciting broad protection.

Investigating the mechanisms of SARS-CoV-2 cellular infection is key to better understand COVID-19 immunity and pathogenesis. Infection, which involves both cell attachment and membrane fusion, relies on the ACE2 receptor that is paradoxically found at low levels in the respiratory tract, suggesting that additional mechanisms facilitating infection may exist. Here we show that C-type lectin receptors, DC-SIGN, L-SIGN and the sialic acid-binding Ig-like lectin 1 (SIGLEC1) function as auxiliary receptors by enhancing ACE2-mediated infection and modulating the neutralizing activity of different classes of spike-specific antibodies. Antibodies to the N-terminal domain (NTD) or to the conserved proteoglycan site at the base of the Receptor Binding Domain (RBD), while poorly neutralizing infection of ACE2 over-expressing cells, effectively block lectin-facilitated infection. Conversely, antibodies to the Receptor Binding Motif (RBM), while potently neutralizing infection of ACE2 over-expressing cells, poorly neutralize infection of cells expressing DC-SIGN or L-SIGN and trigger fusogenic rearrangement of the spike promoting cell-to-cell fusion. Collectively, these findings identify a lectin-dependent pathway that enhances ACE2-dependent infection by SARS-CoV-2 and reveal distinct mechanisms of neutralization by different classes of spike-specific antibodies.

The recent emergence of SARS-CoV-2 variants of concern (VOC) and the recurrent spillovers of coronaviruses in the human population highlight the need for broadly neutralizing antibodies that are not affected by the ongoing antigenic drift and that can prevent or treat future zoonotic infections. Here, we describe a human monoclonal antibody (mAb), designated S2×259, recognizing a highly conserved cryptic receptor-binding domain (RBD) epitope and cross-reacting with spikes from all sarbecovirus clades. S2×259 broadly neutralizes spike-mediated entry of SARS-CoV-2 including the B.1.1.7, B.1.351, P.1 and B.1.427/B.1.429 VOC, as well as a wide spectrum of human and zoonotic sarbecoviruses through inhibition of ACE2 binding to the RBD. Furthermore, deep-mutational scanning and in vitro escape selection experiments demonstrate that S2×259 possesses a remarkably high barrier to the emergence of resistance mutants. We show that prophylactic administration of S2×259 protects Syrian hamsters against challenges with the prototypic SARS-CoV-2 and the B.1.351 variant, suggesting this mAb is a promising candidate for the prevention and treatment of emergent VOC and zoonotic infections. Our data unveil a key antigenic site targeted by broadly-neutralizing antibodies and will guide the design of pan-sarbecovirus vaccines.

The SARS-CoV-2 spike (S) glycoprotein contains an immunodominant receptor-binding domain (RBD) targeted by most neutralizing antibodies (Abs) in COVID-19 patient plasma. Little is known about neutralizing Abs binding to epitopes outside the RBD and their contribution to protection. Here, we describe 41 human monoclonal Abs (mAbs) derived from memory B cells, which recognize the SARS-CoV-2 S N-terminal domain (NTD) and show that a subset of them neutralize SARS-CoV-2 ultrapotently. We define an antigenic map of the SARS-CoV-2 NTD and identify a supersite (designated site i) recognized by all known NTD-specific neutralizing mAbs. These mAbs inhibit cell-to-cell fusion, activate effector functions, and protect Syrian hamsters from SARS-CoV-2 challenge, albeit selecting escape mutants in some animals. Indeed, several SARS-CoV-2 variants, including the B.1.1.7, B.1.351 and P1 lineages, harbor frequent mutations within the NTD supersite suggesting ongoing selective pressure and the importance of NTD-specific neutralizing mAbs for protective immunity and vaccine design., McCallum et al. identify a supersite in the N-terminal domain of SARS-CoV-2 spike protein that is targeted by neutralizing antibodies and exhibits mutation in response to selective pressure.

SARS-CoV-2 infection-which involves both cell attachment and membrane fusion-relies on the angiotensin-converting enzyme 2 (ACE2) receptor, which is paradoxically found at low levels in the respiratory tract(1-3), suggesting that there may be additional mechanisms facilitating infection. Here we show that C-type lectin receptors, DC-SIGN, L-SIGN and the sialic acid-binding immunoglobulin-like lectin 1 (SIGLEC1) function as attachment receptors by enhancing ACE2-mediated infection and modulating the neutralizing activity of different classes of spike-specific antibodies. Antibodies to the amino-terminal domain or to the conserved site at the base of the receptor-binding domain, while poorly neutralizing infection of ACE2-overexpressing cells, effectively block lectin-facilitated infection. Conversely, antibodies to the receptor binding motif, while potently neutralizing infection of ACE2-overexpressing cells, poorly neutralize infection of cells expressing DC-SIGN or L-SIGN and trigger fusogenic rearrangement of the spike, promoting cell-to-cell fusion. Collectively, these findings identify a lectin-dependent pathway that enhances ACE2-dependent infection by SARS-CoV-2 and reveal distinct mechanisms of neutralization by different classes of spike-specific antibodies.

A strong cocktail against SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is initiated by the trimeric spike protein that decorates the virus and binds the ACE2 receptor. Antibodies against the spike that neutralize viral infection have potential as therapeutics. Tortorici et al. describe two very potent antibodies, S2E12 and S2M11. Electron microscopy structures characterized the binding and showed that S2E12 traps the spike in a conformation that cannot bind ACE2. Both antibodies protected hamsters against SARS-CoV-2 challenge and may be useful in antibody cocktails to combat the virus and prevent the development of resistance. Science, this issue p. 950, A potent antibody cocktail blocks attachment of SARS-CoV-2 to the host receptor and activates a protective immune response., Efficient therapeutic options are needed to control the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has caused more than 922,000 fatalities as of 13 September 2020. We report the isolation and characterization of two ultrapotent SARS-CoV-2 human neutralizing antibodies (S2E12 and S2M11) that protect hamsters against SARS-CoV-2 challenge. Cryo–electron microscopy structures show that S2E12 and S2M11 competitively block angiotensin-converting enzyme 2 (ACE2) attachment and that S2M11 also locks the spike in a closed conformation by recognition of a quaternary epitope spanning two adjacent receptor-binding domains. Antibody cocktails that include S2M11, S2E12, or the previously identified S309 antibody broadly neutralize a panel of circulating SARS-CoV-2 isolates and activate effector functions. Our results pave the way to implement antibody cocktails for prophylaxis or therapy, circumventing or limiting the emergence of viral escape mutants.

Background Prostate cancer (PCa) is the most prevalent solid cancer among men in Western Countries. The clinical behavior of localized PCa is highly variable. Some cancers are aggressive leading to death, while others can even be monitored safely. Hence, there is a high clinical need for precise biomarkers for identification of aggressive disease in addition to established clinical parameters. Objective To develop an RNA expression-based score for the prediction of PCa prognosis that facilitates clinical decision making. Design, setting, and participants We assessed 233 tissue specimens of PCa patients with long-term follow-up data from fresh-frozen radical prostatectomies (RPs), from formalin-fixed and paraffin-embedded RP specimens and biopsies by transcriptome-wide next-generation sequencing and customized expression microarrays. Outcome measurements and statistical analysis We applied Cox proportional hazard models to the cohorts from different platforms and specimen types. Evidence from these models was combined by fixed-effect meta-analysis to identify genes predictive of the time to death of disease (DoD). Genes were combined by a weighted median approach into a prognostic score called ProstaTrend and transferred for the prediction of biochemical recurrence (BCR) after RP in an independent cohort of The Cancer Genome Atlas (TCGA). Results and limitations ProstaTrend comprising ∼1400 genes was significantly associated with DoD in the training cohort of PCa patients treated by RP (leave-one-out cross-validation, Cox regression: p = 2e-09) and with BCR in the TCGA validation cohort (Cox regression: p = 3e-06). The prognostic impact persisted after multivariable Cox regression analysis adjusting for Gleason grading group (GG) ≥3 and resection status (p = 0.001; DoD, training cohort) and for GG ≥ 3, pathological stage ≥T3, and resection state (p = 0.037; BCR, validation cohort). Conclusions ProstaTrend is a transcriptome-based score that predicts DoD and BCR in cohorts of PCa patients treated with RP. Patient summary ProstaTrend provides molecular patient risk stratification after radical prostatectomy.

Background Influenza A viruses are responsible for seasonal epidemics and represent a constant pandemic threat. Influenza vaccines induce predominantly antibodies against the head region of hemagglutinin (HA) and are strain specific. Vaccine effectiveness is often suboptimal due to mismatch with drifting viruses and an inadequate immune response. Broadly neutralizing monoclonal antibodies (mAbs) targeting the conserved stem-region of HA may provide protection through multiple seasons and cover strains with pandemic potential. We report pre-clinical data on VIR-2482, a fully human anti-HA stem mAb with half-life extending Fc mutations. Methods Binding of VIR-2482 to a panel of influenza HAs and neutralization of H1N1 and H3N2 viruses were measured by ELISA and microneutralization. Epitope conservation was evaluated using 49,462 HA sequences retrieved from GiSAID. Engagement of human FcγRs by VIR-2482 was assessed by biolayer interferometry. Antibody-dependendent cell-mediated cytoxicity (ADCC) was measured via in vitro killing of A549 cells expressing H1-HA glycoprotein by human NK cells. Complement-dependent cytotoxicity (CDC) was evaluated by incubating VIR-2482 with H1N1 infected cells in the presence of guinea pig complement. Protection studies were performed in Balb/c mice given VIR-2482 24h before intranasal infection with a lethal dose of H1N1 PR8 and H3N2 HK/68. Results VIR-2482 binds to the HA proteins representing all 18 influenza A HA subtypes and neutralizes a broad panel of H1N1 and H3N2 viruses spanning almost 100 years of evolution. Bioinformatic analysis revealed >98.8% conservation for the majority of key contact residues examined from sequences retrieved for H1N1 and H3N2 between 2009-2019. The half-life extending mutations in the Fc portion do not affect the ability of the antibody to engage FcγRIIIa, FcγRIIa, and C1q as evidenced by their lack of impact on ADCC and CDC in vitro. Prophylactic administration of VIR-2482 protects Balb/c mice from infection with lethal challenge doses of H1N1 and H3N2 viruses. Conclusion The attributes of potency, broad recognition of a highly conserved epitope, retention of high-level effector functions in addition to half-life extension support the development of VIR-2482 as a universal prophylactic for influenza A illness. Disclosures Matteo Samuele Pizzuto, PhD, VIR Biotechnology (Employee) Fabrizia Zatta, n/a, Vir Biotechnology (Employee) Andrea Minola, MS, Vir Biotechnology (Employee) Alessia Peter, n/a, Vir Biotechnology (Employee) Katja Culap, n/a, Vir Biotechnology (Employee) Leah Soriaga, PhD, Vir Biotechnology (Employee) Anna De Marco, n/a, Vir Biotechnology (Employee) Barbara Guarino, PhD, Vir Biotechnology (Employee) Nadia Passini, n/a, Vir Biotechnology (Employee) David K. Hong, MD, Vir Biotechnology (Employee) Fabio Benigni, PhD, Vir Biotechnology (Employee) Christy Hebner, PhD, Vir Biotechnology (Employee) Aurelio Bonavia, PhD, Vir Biotechnology (Employee) Davide Corti, PhD, Vir Biotechnology (Employee)

The aim of the study was to investigate the association of the uromodulin (UMOD) genotype with patient health status and with renal cell carcinoma (RCC) aggressiveness.The UMOD genotype at the top single nucleotide variant rs4293393 was determined in a cohort of 211 patients diagnosed with a renal mass and treated with surgery. Clinical data were prospectively collected. Due to the higher frequency of allele T relative to the lower frequency of allele C, recessive homozygous (CC), and heterozygous (TC) patients were grouped together and compared with homozygous (TT) patients. Mann-Whitney and chi-square tests were used to compare clinical characteristics after stratification for the UMOD genotype. UMOD genotype frequencies resulted TT and TC-CC in 67% (n = 141) and 33% (n = 70) of the population, respectively. The rate of cM1 RCC at clinical staging was higher in patients with genotype TT relative to patients with genotype TC-CC (18% vs 1%, p = 0.001). Similarly, the rate of pT3-pT4 (41% vs 25%, p = 0.047) and lymphovascular invasion (29% vs 13%, p = 0.02) RCC at final pathology were higher in patients with genotype TT relative to patients with genotype TC-CC. Patient summary: In patients diagnosed with renal cell carcinoma and treated with surgery, uromodulin homozygous genotype is associated with more aggressive renal cell carcinoma clinical and pathological characteristics. In patients diagnosed with a renal mass and elected for surgical management, uromodulin homozygous genotype is associated with more aggressive renal cell carcinoma clinical and pathological characteristics. Further investigations are required to study the causal biologic mechanism underlying such relationship.

While the cellular immune response associated with acute and chronic HBV infection has been thoroughly studied, the B cell response in chronic hepatitis B and the role of antibodies raised against the HBV envelope antigens in controlling and prevention of infection requires further investigation. The detection of anti-HBs antibodies is considered as one of the biomarkers for functional cure of chronic hepatitis B virus infection, as well as for protective immunity. Indeed, vaccine-induced neutralizing anti-HBs antibodies have been shown to protect against HBV challenge. Yet, the therapeutic potential of viral envelope-specific antibodies and the mechanism involved in protection and prevention of cell-to-cell transmission warrants additional investigative efforts. In this review, we will provide a critical overview of the available preclinical and clinical literature supporting the putative role of active and passive vaccination and neutralizing envelope-specific antibodies for therapeutic intervention in combination regimens intended to cure persistent HBV infection.

Renal cell carcinomas (RCCs) are common cancers diagnosed in more than 350,000 people each year worldwide. Several pathways are de-regulated in RCCs, including mTORC1. However, how mTOR drives tumorigenesis in this context is unknown. The lack of faithful animal models has limited progress in understanding and targeting RCCs. Here, we generated a mouse model harboring the kidney-specific inactivation of Tsc1. These animals develop cysts that evolve into papillae, cystadenomas, and papillary carcinomas. Global profiling confirmed several metabolic derangements previously attributed to mTORC1. Notably, Tsc1 inactivation results in the accumulation of fumarate and in mTOR-dependent downregulation of the TCA cycle enzyme fumarate hydratase (FH). The re-expression of FH in cellular systems lacking Tsc1 partially rescued renal epithelial transformation. Importantly, the mTORC1-FH axis is likely conserved in human RCC specimens. We reveal a role of mTORC1 in renal tumorigenesis, which depends on the oncometabolite fumarate. Renal cell carcinomas are common human cancers whose modeling in mice has proved difficult. Drusian et al. show that kidney-specific inactivation of Tsc1 results in benign lesions that gradually transform into malignant carcinomas. Metabolomic profiling revealed that mTORC1 upregulation leads to accumulation of fumarate, an oncometabolite that contributes to transformation.

Epithelial Ovarian Cancer (EOC) “cholinic phenotype”, characterized by increased intracellular phosphocholine content sustained by over-expression/activity of choline kinase-alpha (ChoKα/CHKA), is a metabolic cellular reprogramming involved in chemoresistance with still unknown mechanisms. By stable CHKA silencing and global metabolic profiling here we demonstrate that CHKA knockdown hampers growth capability of EOC cell lines both in vitro and in xenotransplant in vivo models. It also affected antioxidant cellular defenses, decreasing glutathione and cysteine content while increasing intracellular levels of reactive oxygen species, overall sensitizing EOC cells to current chemotherapeutic regimens. Natural recovering of ChoKα expression after its transient silencing rescued the wild-type phenotype, restoring intracellular glutathione content and drug resistance. Rescue and phenocopy of siCHKA-related effects were also obtained by artificial modulation of glutathione levels. The direct relationship among CHKA expression, glutathione intracellular content and drug sensitivity was overall demonstrated in six different EOC cell lines but notably, siCHKA did not affect growth capability, glutathione metabolism and/or drug sensitivity of non-tumoral immortalized ovarian cells. The “cholinic phenotype”, by recapitulating EOC addiction to glutathione content for the maintenance of the antioxidant defense, can be therefore considered a unique feature of cancer cells and a suitable target to improve chemotherapeutics efficacy.

Efficient targeting in tumor therapies is still an open issue: systemic biodistribution and poor specific accumulation of drugs weaken efficacy of treatments. Engineered nanoparticles are expected to bring benefits by allowing specific delivery of drug to the tumor or acting themselves as localized therapeutic agents. In this study we have targeted epithelial ovarian cancer with inorganic nanoparticles conjugated to a human antibody fragment against the folate receptor over-expressed on cancer cells. The conjugation approach is generally applicable. Indeed several types of nanoparticles (either magnetic or fluorescent) were engineered with the fragment, and their biological activity was preserved as demonstrated by biochemical methods in vitro. In vivo studies with mice bearing orthotopic and subcutaneous tumors were performed. Elemental and histological analyses showed that the conjugated magnetic nanoparticles accumulated specifically and were retained at tumor sites longer than the non-conjugated nanoparticles.

Lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH) are associated with erectile dysfunction. Alpha-1-adrenoceptor antagonists are effective drugs for treating symptomatic BPH. Clinical data show improvements in LUTS by phosphodiesterase 5 inhibitors. This study aimed to evaluate effects of silodosin, a highly selective α1A-adrenoceptor antagonist, alone or in combination with the phosphodiesterase 5 inhibitor tadalafil on contractions of isolated human and rat prostates. In organbath studies, effects of increasing concentrations of silodosin (1 nM-1 μM) and tadalafil (100 nM-100 μM) on contractions by electrical field stimulation or phenylephrine of human and rat prostate strip preparations were investigated. The combination silodosin and tadalafil reduced electrically-induced contractions of human prostate preparations better than single drugs alone. At any frequencies (1-32 Hz), inhibitory effects of combined therapy (P-values vs single drug) in human tissue were 26-42% (1 nM silodosin+100 nM tadalafil; P

The endocannabinoid system (ECS), comprising the cannabinoid receptors (CBR), their ligands, and enzymes controlling the turnover of endocannabinoids, has been suggested to be involved in male reproductive function. As information is scarce on the expression of the ECS in human male reproductive tissues, this study aimed to investigate by means of molecular biology (RT-PCR) and immunohistochemistry/immunofluorescence the expression and distribution of CB1 and CB2, GPR55 (an orphan G protein-coupled receptor that recognises cannabinoid ligands) and FAAH (isoforms 1 and 2) in the human seminal vesicles (SV). The specimens expressed PCR products corresponding to CB1 (66 bp), CB2 (141 bp), GPR55 (112 bp), FAAH1 (260 bp) and FAAH2 (387 bp). Immumohistochemistry revealed dense expression of CB1, CB2 and GPR55 located to the pseudo-stratified columnar epithelium and varicose nerves (also characterised by the expression of vasoactive intestinal polypeptide and calcitonin gene-related peptide). Cytosolic staining for FAAH1 and FAAH2 was seen in cuboidal cells of all layers of the epithelium. No immunoreactivity was detected in the smooth musculature or nerve fibres. CB1, CB2, GPR55, FAAH1 and FAAH2 are highly expressed in the human SV. Considering their localisation, the ECS may be involved in epithelial homeostasis, secretory function or autonomic mechano-afferent signalling.

The inhibitory effects demonstrated by activation of cannabinoid receptors (CB) on cancer proliferation and migration may also play critical roles in controlling bladder cancer (BC). CB expression on human normal and BC specimens was tested by immunohistochemistry. Human BC cells RT4 and RT112 were challenged with CB agonists and assessed for proliferation, apoptosis, and motility. Cellular sphingolipids (SL) constitution and metabolism were evaluated after metabolic labelling. CB1-2 were detected in BC specimens, but only CB2 was more expressed in the tumour. Both cell lines expressed similar CB2. Exposure to CB2 agonists inhibited BC growth, down-modulated Akt, induced caspase 3-activation and modified SL metabolism. Baseline SL analysis in cell lines showed differences linked to unique migratory behaviours and cytoskeletal re-arrangements. CB2 activation changed the SL composition of more aggressive RT112 cells by reducing (p amp;lt; 0.01) Gb3 ganglioside (-50 +/- 3%) and sphingosine 1-phosphate (S1P, -40 +/- 4%), which ended up to reduction in cell motility (-46 +/- 5%) with inhibition of p-SRC. CB2-selective antagonists, gene silencing and an inhibitor of SL biosynthesis partially prevented CB2 agonist-induced effects on cell viability and motility. CB2 activation led to ceramide-mediated BC cell apoptosis independently of SL constitutive composition, which instead was modulated by CB2 agonists to reduce cell motility. Funding Agencies|Lions Club Milano ai Cenacoli

Mesenchymal stem cells (MSC) as vehicles of therapeutic genes represent a unique tool to activate drugs within a neoplastic mass due to their property to home and engraft into tumours. In particular, MSC expressing the cytosine deaminase::uracil phosphoribosyltransferase (CD-MSC) have been previously demonstrated to inhibit growth of subcutaneous prostate cancer xenografts thanks to their ability to convert the non-toxic 5-fluorocytosine into the antineoplastic 5-fluorouracil. Since both the immune system and the tumour microenvironment play a crucial role in directing cancer progression, in order to advance towards clinical applications, we tested the therapeutic potential of this approach on animal models that develop autochthonous prostate cancer and preserve an intact immune system. As cell vectors, we employed adipose-tissue and bone-marrow MSC. CD-MSC toxicity on murine prostate cancer cells and tumour tropism were verified in vitro and ex-vivo before starting the preclinical studies. Magnetic Resonance Imaging was utilised to follow orthotopic tumour progression. We demonstrated that intravenous injections of CD-MSC cells, followed by intraperitoneal administration of 5-fluorocytosine, caused tumour regression in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model, which develops aggressive and spontaneous prostate cancer. These results add new insights to the therapeutic potential of specifically engineered MSC in prostate cancer disease.

Objectives: The aim of the study was to systematically review the effects of the adrenoreceptor A1D antagonist naftopidil in the management of lower urinary tract symptoms (LUTS). Methods: A structured and comprehensive MEDLINE search was conducted for original articles, reviews, and metanalyses assessing the clinical pharmacology as well as the safety of naftopidil in the treatment of LUTS secondary to BPH. English-language publications dating from 1950 to 2013 were considered. Results: In the considered timeframe, 14 randomized clinical trials (RCT) were reported. Overall, the outcome measures assessed in the various reports included in the present review were changes from baseline in: International Prostate Symptom Score (IPSS), quality of life (QoL) score, maximum urinary flow rate (Qmax), residual volume (PVR), and adverse effects. Although additional well designed, worldwide, placebo-controlled and randomized studies are necessary to confirm the long-term outcomes of naftopidil pharmacotherapy, current data suggest that naftopidil administration in BPH patients provides comparable improvements in total IPSS, QoL, and urinary symptoms from baseline relative to 0.2 mg/d tamsulosin and 8 mg/d silodosin. However, improvements in Qmax are generally less with naftopidil than with tamsulosin. Reported adverse effects related to naftopidil administration are negligible and usually mild. Conclusion: It remains unknown whether the data reported on naftopidil in the Japanese population are applicable in symptomatic BPH patients from western countries given that: (1) no English-language clinical trials have compared naftopidil to placebo in Western countries; (2) all clinical trials available were carried out in Japan; (3) in the comparative studies with tamsulosin, the dose of this drug was lower than the recommended dose in Western countries; (4) no data from long-term clinical trials evaluating drug safety beyond 18 weeks. © 2014 Informa UK Ltd.

AIMS:To study micturition and bladder overactivity in female rats after chronic treatment with the fatty acid amide hydrolase (FAAH) inhibitor oleoyl ethyl amide (OEtA).METHODS:Sprague-Dawley rats ...

Background and Purpose 1-adrenoceptor (-AR) antagonists may facilitate ureter stone passage in humans. We aimed to study effects by the 1A-AR selective antagonist silodosin (compared to tamsulosin and prazosin) on ureter pressures in a rat model of ureter obstruction, and on contractions of human and rat isolated ureters. Experimental Approach After ethical approval, ureters of male rats were cannulated beneath the kidney pelvis for in vivo ureteral intraluminal recording of autonomous peristaltic pressure waves. A partial ureter obstruction was applied to the distal ureter. Mean arterial blood pressure (MAP) was recorded. Approximate clinical and triple clinical doses of the 1-AR antagonists were given intravenously. Effects by the 1-AR antagonists on isolated human and rat ureters were studied in organ baths. Key Results Intravenous silodosin (0.10.3mgkg1) or prazosin (0.030.1mgkg1) reduced obstruction-induced increases in intraluminal ureter pressures by 2137% or 1840% respectively. Corresponding effects by tamsulosin (0.01 or 0.03mgkg1) were 920%. Silodosin, prazosin and tamsulosin reduced MAP by 1012%, 2526% (P < 0.05), or 1825% (P < 0.05) respectively. When effects by the 1A-AR antagonists on obstruction-induced ureter pressures were expressed as a function of MAP, silodosin had six- to eightfold and 2.5- to eightfold better efficacy than tamsulosin or prazosin respectively. Silodosin effectively reduced contractions of both human and rat isolated ureters. Conclusions and Implications Silodosin inhibits contractions of the rat and human isolated ureters and has excellent functional selectivity in vivo to relieve pressure-load of the rat obstructed ureter. Silodosin as pharmacological ureter stone expulsive therapy should be clinically further explored.

Warm renal ischemia performed during partial nephrectomy has been found to be associated with kidney disease. Since endogenous ouabain (EO) is a neuro-endocrine hormone involved in renal damage, we evaluated the role of EO in renal ischemia-reperfusion injury (IRI). We measured plasma and renal EO variations and markers of glomerular and tubular damage (nephrin, KIM-1, Kidney-Injury-Molecule-1, α1 Na-K ATPase) and the protective effect of the ouabain inhibitor, rostafuroxin. We studied five groups of rats: (1) normal; (2) infused for eight weeks with ouabain (30 µg/kg/day, OHR) or (3) saline; (4) ouabain; or (5) saline-infused rats orally treated with 100 µg/kg/day rostafuroxin for four weeks. In group 1, 2–3 h after IRI, EO increased in ischemic kidneys while decreased in plasma. Nephrin progressively decreased and KIM-1 mRNA increased starting from 24 h. Ouabain infusion (group 2) increased blood pressure (from 111.7 to 153.4 mmHg) and ouabain levels in plasma and kidneys. In OHR ischemic kidneys at 120 h from IRI, nephrin, and KIM-1 changes were greater than those detected in the controls infused with saline (group 3). All these changes were blunted by rostafuroxin treatment (groups 4 and 5). These findings support the role of EO in IRI and suggest that rostafuroxin pre-treatment of patients before partial nephrectomy with warm ischemia may reduce IRI, particularly in those with high EO.

The transient receptor potential melastin 8 ion channel (TRPM8) is implicated in bladder sensing but limited information on TRPM8 antagonists in bladder overactivity is available. This study characterizes a new TRPM8-selective antagonist (DFL23448 [5-(2-ethyl-2H-tetrazol-5-yl)-2-(3-fluorophenyl)-1,3-thiazol-4-ol]) and evaluates it in cold-induced behavioral tests and tests on bladder function and experimental bladder overactivity in vivo in rats. DFL23448 displayed IC50 values of 10 and 21 nM in hTRPM8 human embryonic kidney 293 cells activated by Cooling Agent 10 or cold, but it had limited activity (IC50 > 10 μM) at transient receptor potential vanilloids TRPV1, TRPA1, or TRPV4 or at various G protein-coupled receptors. In rats, DFL23448 administered intravenously or orally had a half-life of 37 minutes or 4.9 hours, respectively. DLF23448 (10 mg/kg i.v.) reduced icilin-induced "wet dog-like" shakes in rats. Intravesical DFL23448 (10 mg/l), but not vehicle, increased micturition intervals, micturition volume, and bladder capacity. During bladder overactivity by intravesical prostaglandin E2 (PGE2), vehicle controls exhibited reductions in micturition intervals, micturition volumes, and bladder capacity by 37%-39%, whereas the same parameters only decreased by 12%-15% (P < 0.05-0.01 versus vehicle) in DFL23448-treated rats. In vehicle-treated rats, but not in DFL23448-treated rats, intravesical PGE2 increased bladder pressures. Intravenous DFL23448 at 10 mg/kg, but not 1 mg/kg DFL23448 or vehicle, increased micturition intervals, micturition volumes, and bladder capacity. During bladder overactivity by intravesical PGE2, micturition intervals, micturition volumes, and bladder capacity decreased in vehicle- and 1 mg/kg DFL23448-treated rats, but not in 10 mg/kg DFL23448-treated rats. Bladder pressures increased less in rats treated with DFL23448 10 mg/kg than in vehicle- or 1 mg/kg DFL23448-treated rats. DFL23448 (10 mg/kg i.v.), but not vehicle, prevented cold stress-induced bladder overactivity. Our results support a role for bladder TRPM8-mediated signals in experimental bladder overactivity.

The triggering receptor expressed on myeloid cell type 1 (TREM-1) is a cell surface molecule that has been identified on both human and murine polymorphonuclear neutrophils and mature monocytes. The activation of TREM-1 in the presence of microbial components amplifies the inflammatory response and may be responsible for the hyperresponsiveness observed during the initial stage of sepsis. To investigate the effect of the modulation of the TREM-1 pathway during experimental murine sepsis, we used analogue synthetic peptides derived from the extracellular moiety of TREM-1. The TREM-1 ligand was expressed on both peritoneal and peripheral neutrophils during experimental peritonitis in mice. The TREM-1 peptides inhibited the recognition by TREM-1 of its ligand and protected endotoxinic mice from death. In septic rats, the TREM-1 peptides improved the hemodynamic status, attenuated the development of lactic acidosis, modulated the production of such proinflammatory cytokines as tumor necrosis factor alpha and interleukin-1β, and improved survival. The protective effect of these peptides on arterial pressure could partly be explained by a decreased production of nitric oxide. These data suggest that in vivo modulation of TREM-1 might be a suitable therapeutic tool for the treatment of sepsis. Copyright © 2006, American Society for Microbiology. All Rights Reserved.

To investigate the effects of a vitamin D3 analogue (BXL628) in a model of chronic cystitis, as calcitriol analogues might be an interesting new therapeutic option for interstitial cystitis, for although the cause of the disease remains unclear, the increase in mast cells in the mucosa and detrusor muscle are significant.We devised a mouse model of allergen-induced allergic cystitis that is associated with the up-regulation of genes for interleukin-13, FcepsilonRIalpha and mast cells-derived proteases, a massive inflammatory reaction in the bladder tissue, and augmented levels of mast cell-derived protease 1 (MMCP1) detected in mouse sera.Oral administration of BXL628 significantly reduced the expression of interleukin-13, FcepsilonRIalpha and MMCP1 in the bladder. Furthermore, histological analysis showed a decrease in oedema and leukocyte infiltration in the bladder wall. BXL628 treatment reduced serum MMCP1 levels, indicating an effect on mast cell degranulation in vivo.Vitamin D3 analogues may successfully be used as anti-inflammatory agents in allergen-mediated inflammatory reactions. Moreover, the modulatory effect shown on mast cell activation by the BXL628 analogue strongly supports its potential therapeutic use in a possibly mast cell-dependent disease such as human interstitial cystitis.

Fas is a receptor of the tumor necrosis factor (TNF)/nerve growth factor (NGF) receptor superfamily that mediates apoptosis and some inflammatory changes. As the central administration of TNF is known to activate the hypothalamus-pituitary-adrenal axis (HPAA) and to induce peripheral responses including induction of serum interleukin (IL)-6 and serum amyloid A (SAA), we investigated the effects of intracerebroventricular (i.c.v.) administration of agonist anti-Fas monoclonal antibody Jo2. Centrally administered anti-Fas (1 μg/mouse, i.c.v.) induced elevated levels of corticosterone, IL-6, and SAA comparable to those observed after i.c.v. administration of recombinant murine TNF. On the other hand, administration of murine NGF did not elevate serum corticosterone or IL-6, but induced SAA. Thus, Fas can trigger a centrally mediated anti-inflammatory response (HPAA activation) and induce a peripheral acute-phase response comparable to that induced with TNF, whereas NGF induces only acute-phase proteins.