Structures of HCMV Trimer reveal the basis for receptor recognition and cell entry.

Human cytomegalovirus (HCMV) infects the majority of the human population and represents the leading viral cause of congenital birth defects. HCMV utilizes the glycoproteins gHgLgO (Trimer) to bind to platelet-derived growth factor receptor alpha (PDGFRα) and transforming growth factor beta receptor 3 (TGFßR3) to gain entry into multiple cell types. This complex is targeted by potent neutralizing antibodies and represents an important candidate for therapeutics against HCMV. Here, we determine three cryogenic electron microscopy (cryo-EM) structures of the trimer and the details of its interactions with four binding partners: the receptor proteins PDGFRα and TGFßR3 as well as two broadly neutralizing antibodies. Trimer binding to PDGFRα and TGFßR3 is mutually exclusive, suggesting that they function as independent entry receptors. In addition, Trimer-PDGFRα interaction has an inhibitory effect on PDGFRα signaling. Our results provide a framework for understanding HCMV receptor engagement, neutralization, and the development of anti-viral strategies against HCMV.

The Immunoglobulin Superfamily Receptome Defines Cancer-Relevant Networks Associated with Clinical Outcome.

Cell surface receptors and their interactions play a central role in physiological and pathological signaling. Despite its clinical relevance, the immunoglobulin superfamily (IgSF) remains uncharacterized and underrepresented in databases. Here, we present a systematic extracellular protein map, the IgSF interactome. Using a high-throughput technology to interrogate most single transmembrane receptors for binding to 445 IgSF proteins, we identify over 500 interactions, 82% previously undocumented, and confirm more than 60 receptor-ligand pairs using orthogonal assays. Our study reveals a map of cell-type-specific interactions and the landscape of dysregulated receptor-ligand crosstalk in cancer, including selective loss of function for tumor-associated mutations. Furthermore, investigation of the IgSF interactome in a large cohort of cancer patients identifies interacting protein signatures associated with clinical outcome. The IgSF interactome represents an important resource to fuel biological discoveries and a framework for understanding the functional organization of the surfaceome during homeostasis and disease, ultimately informing therapeutic development.

An Unbiased Screen for Human Cytomegalovirus Identifies Neuropilin-2 as a Central Viral Receptor.

Characterizing cell surface receptors mediating viral infection is critical for understanding viral tropism and developing antiviral therapies. Nevertheless, due to challenges associated with detecting protein interactions on the cell surface, the host receptors of many human pathogens remain unknown. Here, we build a library consisting of most single transmembrane human receptors and implement a workflow for unbiased and high-sensitivity detection of receptor-ligand interactions. We apply this technology to elucidate the long-sought receptor of human cytomegalovirus (HCMV), the leading viral cause of congenital birth defects. We identify neuropilin-2 (Nrp2) as the receptor for HCMV-pentamer infection in epithelial/endothelial cells and uncover additional HCMV interactors. Using a combination of biochemistry, cell-based assays, and electron microscopy, we characterize the pentamer-Nrp2 interaction and determine the architecture of the pentamer-Nrp2 complex. This work represents an important approach to the study of host-pathogen interactions and provides a framework for understanding HCMV infection, neutralization, and the development of novel anti-HCMV therapies.

Assembly and Function of Heterotypic Ubiquitin Chains in Cell-Cycle and Protein Quality Control.

Posttranslational modification with ubiquitin chains controls cell fate in all eukaryotes. Depending on the connectivity between subunits, different ubiquitin chain types trigger distinct outputs, as seen with K48- and K63-linked conjugates that drive protein degradation or complex assembly, respectively. Recent biochemical analyses also suggested roles for mixed or branched ubiquitin chains, yet without a method to monitor endogenous conjugates, the physiological significance of heterotypic polymers remained poorly understood. Here, we engineered a bispecific antibody to detect K11/K48-linked chains and identified mitotic regulators, misfolded nascent polypeptides, and pathological Huntingtin variants as their endogenous substrates. We show that K11/K48-linked chains are synthesized and processed by essential ubiquitin ligases and effectors that are mutated across neurodegenerative diseases; accordingly, these conjugates promote rapid proteasomal clearance of aggregation-prone proteins. By revealing key roles of K11/K48-linked chains in cell-cycle and quality control, we establish heterotypic ubiquitin conjugates as important carriers of biological information.

Homeostatic functions of monocytes and interstitial lung macrophages are regulated via collagen domain-binding receptor LAIR1.

Myeloid cells encounter stromal cells and their matrix determinants on a continual basis during their residence in any given organ. Here, we examined the impact of the collagen receptor LAIR1 on myeloid cell homeostasis and function. LAIR1 was highly expressed in the myeloid lineage and enriched in non-classical monocytes. Proteomic definition of the LAIR1 interactome identified stromal factor Colec12 as a high-affinity LAIR1 ligand. Proteomic profiling of LAIR1 signaling triggered by Collagen1 and Colec12 highlighted pathways associated with survival, proliferation, and differentiation. Lair1-/- mice had reduced frequencies of Ly6C- monocytes, which were associated with altered proliferation and apoptosis of non-classical monocytes from bone marrow and altered heterogeneity of interstitial macrophages in lung. Myeloid-specific LAIR1 deficiency promoted metastatic growth in a melanoma model and LAIR1 expression associated with improved clinical outcomes in human metastatic melanoma. Thus, monocytes and macrophages rely on LAIR1 sensing of stromal determinants for fitness and function, with relevance in homeostasis and disease.

A membrane protein display platform for receptor interactome discovery.

Cell surface receptors are critical for cell signaling and constitute a quarter of all human genes. Despite their importance and abundance, receptor interaction networks remain understudied because of difficulties associated with maintaining membrane proteins in their native conformation and their typically weak interactions. To overcome these challenges, we developed an extracellular vesicle-based method for membrane protein display that enables purification-free and high-throughput detection of receptor-ligand interactions in membranes. We demonstrate that this platform is broadly applicable to a variety of membrane proteins, enabling enhanced detection of extracellular interactions over a wide range of binding affinities. We were able to recapitulate and expand the interactome for prominent members of the B7 family of immunoregulatory proteins such as PD-L1/CD274 and B7-H3/CD276. Moreover, when applied to the orphan cancer-associated fibroblast protein, LRRC15, we identified a membrane-dependent interaction with the tumor stroma marker TEM1/CD248. Furthermore, this platform enabled profiling of cellular receptors for target-expressing as well as endogenous extracellular vesicles. Overall, this study presents a sensitive and easy to use screening platform that bypasses membrane protein purification and enables characterization of interactomes for any cell surface-expressed target of interest in its native state.

Evaluating the impact of plain packaging among Canadian smokers: findings from the 2018 and 2020 ITC Smoking and Vaping Surveys.

BACKGROUND: In February 2020, Canada implemented plain packaging without any changes to the size and content of health warning labels (HWLs), which were last updated in 2012 (pictorial HWLs on 75% of the pack front and back). This pre-post evaluation study assessed the impact of plain packaging in Canada on: (1) pack appeal; (2) HWL effectiveness; and (3) support for plain packaging. Additionally, a quasi-experimental design was used to assess the Canadian results relative to two comparator countries: Australia, where plain packaging (with new larger HWLs) was implemented in 2012, and the United States (USA), where plain packaging has not been implemented and the same text warnings have appeared on cigarette packs since 1985. METHODS: Data are from adult smokers who participated in the 2018 and/or 2020 International Tobacco Control Smoking and Vaping Surveys in Canada (n=4600), Australia (n=1834) and the USA (n=3046). Online surveys were conducted before (February to July 2018) and after (February to June 2020) the implementation of plain packaging in Canada. Adjusted regression analyses were conducted on weighted data. RESULTS: Plain packaging was associated with a significant increase in the percentage of Canadian smokers who did not like the look of their cigarette pack (2018: 28.6% vs 2020: 44.7%, p<0.001), whereas no change in pack appeal was observed among smokers in Australia and the USA over the same period. Plain packaging was not associated with changes in HWL effectiveness in Canada. Support for plain packaging increased significantly among Canadian smokers (2018: 25.6% vs 2020: 33.7%, p<0.001). CONCLUSIONS: Plain packaging in Canada substantially reduced pack appeal and increased support for the policy among adult smokers; however, there was no increase in the effectiveness of Canada's 8-year-old HWLs. The impact of plain packaging on health warning effectiveness may depend on the design of the warnings and length of time since implementation.

Cutting Edge: IL-17B Uses IL-17RA and IL-17RB to Induce Type 2 Inflammation from Human Lymphocytes.

IL-17 family cytokines are critical to host defense responses at cutaneous and mucosal surfaces. Whereas IL-17A, IL-17F, and IL-17C induce overlapping inflammatory cascades to promote neutrophil-mediated immunity, IL-17E/IL-25 drives type 2 immune pathways and eosinophil activity. Genetic and pharmacological studies reveal the significant contribution these cytokines play in antimicrobial and autoimmune mechanisms. However, little is known about the related family member, IL-17B, with contrasting reports of both pro- and anti-inflammatory function in rodents. We demonstrate that in the human immune system, IL-17B is functionally similar to IL-25 and elicits type 2 cytokine secretion from innate type 2 lymphocytes, NKT, and CD4+ CRTH2+ Th2 cells. Like IL-25, this activity is dependent on the IL-17RA and IL-17RB receptor subunits. Furthermore, IL-17B can augment IL-33-driven type 2 responses. These data position IL-17B as a novel component in the regulation of human type 2 immunity.

Self-Reported Quit Aids and Assistance Used By Smokers At Their Most Recent Quit Attempt: Findings from the 2020 International Tobacco Control Four Country Smoking and Vaping Survey.

INTRODUCTION: This study retrospectively describes smoking cessation aids, cessation services, and other types of assistance used by current and ex-smokers at their last quit attempt in four high-income countries. AIMS AND METHODS: Data are from the Wave 3 (2020) International Tobacco Control Four Country Smoking and Vaping Survey in Australia, Canada, England, and the United States (US). Eligible respondents were daily smokers or past-daily recent ex-smokers who made a quit attempt/quit smoking in the last 24-months, resulting in 3614 respondents. Self-reported quit aids/assistance included: nicotine vaping products (NVPs), nicotine replacement therapy (NRT), other pharmacological therapies (OPT: varenicline/bupropion/cytisine), tobacco (noncombustible: heated tobacco product/smokeless tobacco), cessation services (quitline/counseling/doctor), other cessation support (e.g., mobile apps/website/pamphlets, etc.), or no aid. RESULTS: Among all respondents, at last quit attempt, 28.8% used NRT, 28.0% used an NVP, 12.0% used OPT, 7.8% used a cessation service, 1.7% used a tobacco product, 16.5% other cessation support, and 38.6% used no aid/assistance. Slightly more than half of all smokers and ex-smokers (57.2%) reported using any type of pharmacotherapy (NRT or OPT) and/or an NVP, half-used NRT and/or an NVP (49.9%), and 38.4% used any type of pharmacotherapy (NRT and/or OPT). A quarter of smokers/ex-smokers used a combination of aids. NVPs and NRT were the most prevalent types of cessation aids used in all four countries; however, NRT was more commonly used in Australia relative to NVPs, and in England, NVPs were more commonly used than NRT. The use of NVPs or NRT was more evenly distributed in Canada and the US. CONCLUSIONS: It appears that many smokers are still trying to quit unassisted, rather than utilizing cessation aids or other forms of assistance. Of those who did use assistance, NRT and NVPs were the most common method, which appears to suggest that nicotine substitution is important for smokers when trying to quit smoking. IMPLICATIONS: Clinical practice guidelines in a number of countries state that the most effective smoking cessation method is a combination of pharmacotherapy and face-to-face behavioral support by a health professional. Most quit attempts however are made unassisted, particularly without the use of government-approved cessation medications. This study found that about two in five daily smokers used approved cessation medications (nicotine replacement therapy (NRT) or other approved pharmacotherapies, such as varenicline). Notably, nicotine substitution in the form of either NRT and nicotine vaping products (NVPs) were the most common method of cessation assistance (used by one in two respondents), but the proportion using NRT and/or NVPs varied by country. Few smokers who attempted to quit utilized cessation services such as stop-smoking programs/counseling or quitlines, despite that these types of support are effective in helping smokers manage withdrawals and cravings. Primary healthcare professionals should ask their patients about smoking and offer them evidence-based treatment, as well as be prepared to provide smokers with a referral to trained cessation counselors, particularly when it comes to tailoring intensive treatment programs for regular daily smokers. Additionally, healthcare providers should be prepared to discuss the use of NVPs, particularly if smokers are seeking advice about NVPs, wanting to try/or already using an NVP to quit smoking, have failed repeatedly to quit with other cessation methods, and/or if they do not want to give up tobacco/nicotine use completely.

A Platform for Extracellular Interactome Discovery Identifies Novel Functional Binding Partners for the Immune Receptors B7-H3/CD276 and PVR/CD155.

Receptors expressed on the plasma membrane and their interacting partners critically regulate cellular communication during homeostasis and disease, and as such represent main therapeutic targets. Despite its importance for drug development, receptor-ligand proteomics has remained a daunting field, in part because of the challenges associated to the study of membrane-expressed proteins. Here, to enable sensitive detection of receptor-ligand interactions in high throughput, we implement a new platform, the Conditioned Media AlphaScreen, for interrogation of a library consisting of most single transmembrane human proteins. Using this method to study key immune receptors, we identify and further validate the interleukin receptor IL20RA as the first binding partner for the checkpoint inhibitor B7-H3. Further, KIR2DL5, a natural killer cell protein that had remained orphan, is uncovered as a functional binding partner for the poliovirus receptor (PVR). This interaction is characterized using orthogonal assays, which demonstrate that PVR specifically engages KIR2DL5 on natural killer cells leading to inhibition of cytotoxicity. Altogether, these results reveal unappreciated links between protein families that may importantly influence receptor-driven functions during disease. Applicable to any target of interest, this technology represents a versatile and powerful approach for elucidation of receptor-ligand interactomes, which is essential to understand basic aspects of the biology of the plasma membrane proteins and ultimately inform the development of novel therapeutic strategies.

The Association of E-cigarette Flavors With Satisfaction, Enjoyment, and Trying to Quit or Stay Abstinent From Smoking Among Regular Adult Vapers From Canada and the United States: Findings From the 2018 ITC Four Country Smoking and Vaping Survey.

AIMS: This study examined whether nontobacco flavors are more commonly used by vapers (e-cigarette users) compared with tobacco flavor, described which flavors are most popular, and tested whether flavors are associated with: vaping satisfaction relative to smoking, level of enjoyment with vaping, reasons for using e-cigarettes, and making an attempt to quit smoking by smokers. METHODS: This cross-sectional study included 1603 adults from Canada and the United States who vaped at least weekly, and were either current smokers (concurrent users) or former smokers (exclusive vapers). Respondents were categorized into one of seven flavors they used most in the last month: tobacco, tobacco-menthol, unflavored, or one of the nontobacco flavors: menthol/mint, fruit, candy, or "other" (eg, coffee). RESULTS: Vapers use a wide range of flavors, with 63.1% using a nontobacco flavor. The most common flavor categories were fruit (29.4%) and tobacco (28.7%), followed by mint/menthol (14.4%) and candy (13.5%). Vapers using candy (41.0%, p < .0001) or fruit flavors (26.0%, p = .01) found vaping more satisfying (compared with smoking) than vapers using tobacco flavor (15.5%) and rated vaping as very/extremely enjoyable (fruit: 50.9%; candy: 60.9%) than those using tobacco flavor (39.4%). Among concurrent users, those using fruit (74.6%, p = .04) or candy flavors (81.1%, p = .003) were more likely than tobacco flavor users (63.5%) to vape in order to quit smoking. Flavor category was not associated with the likelihood of a quit attempt (p = .46). Among exclusive vapers, tobacco and nontobacco flavors were popular; however, those using tobacco (99.0%) were more likely than those using candy (72.8%, p = .002) or unflavored (42.5%, p = .005) to vape in order to stay quit. CONCLUSIONS: A majority of regular vapers in Canada and the US use nontobacco flavors. Greater satisfaction and enjoyment with vaping are higher among fruit and candy flavor users. While it does not appear that certain flavors are associated with a greater propensity to attempt to quit smoking among concurrent users, nontobacco flavors are popular among former smokers who are exclusively vaping. Future research should determine the likely impact of flavor bans on those who are vaping to quit smoking or to stay quit. IMPLICATIONS: Recent concerns about the attractiveness of e-cigarette flavors among youth have resulted in flavor restrictions in some jurisdictions of the United States and Canada. However, little is known about the possible consequences for current and former smokers if they no longer have access to their preferred flavors. This study shows that a variety of nontobacco flavors, especially fruit, are popular among adult vapers, particularly among those who have quit smoking and are now exclusively vaping. Limiting access to flavors may therefore reduce the appeal of e-cigarettes among adults who are trying to quit smoking or stay quit.

Avian injury quantification using the Shoreline Deposition Model and model sensitivities.

Deposition models, such as the Shoreline Deposition Model (SDM) used to quantify nearshore avian injuries resulting from the 2010 Deepwater Horizon (DWH) oil spill, were developed to improve the estimates of nearshore avian mortality resulting from the release of oil into coastal and marine environments. Unlike earlier approaches to injury quantification, such as simple counts of carcasses on the shoreline, a modeling approach allows trustees to evaluate the precision of their estimate (i.e., to develop a confidence interval) and can inform decision-making and the likely utility of additional primary data collection activities through sensitivity analyses. In this paper, we rely on published literature, actual DWH data, and a deposition model simulation to evaluate how different model inputs and assumptions can affect the accuracy and precision of model results. We find that the precision of deposition models is strongly affected by the length of time between subsequent shoreline searches, the underlying magnitude of carcass deposition, carcass persistence probabilities, and carcass detection probabilities. In addition, the accuracy of deposition model results may be affected by natural fluctuations in deposition rates. Given these findings, we recommend that natural resource trustees include an evaluation of future model uncertainty as part of their initial data collection efforts. This will allow them to deploy resources in a way that maximizes the utility of future deposition model results. We also identify several factors that do not need to be assessed immediately following a spill event, thereby potentially freeing resources for more time critical data collection efforts.

Evaluation of the fate of carcasses and dummies deployed in the nearshore and offshore waters of the northern Gulf of Mexico.

In response to the Deepwater Horizon oil spill, federal and state agencies conducted field studies to develop inputs for a shoreline deposition model used to estimate nearshore avian mortality resulting from the spill. A 2011 carcass drift study was designed to generate data on the likelihood that birds that died on the water would deposit along the northern Gulf of Mexico coast (rather than becoming lost at sea). In the case of the Deepwater Horizon oil spill, carcass losses at sea accounted for a significant portion of nearshore avian mortality. We evaluate the data collected during the Deepwater Horizon carcass drift study and compare the results obtained from the use of avian carcasses versus dummy carcasses (dummies) and the differences between those deployed nearshore versus further offshore. We conclude that, although the use of dummies provided valuable confirmation on the drift patterns of dead birds, dummies drifted greater distances, for longer periods of time, and were more likely to be observed beached compared to avian carcasses, with 64.6% of dummies beaching compared to 17.2% of carcasses. In response to future spills, researchers should account for these potential biases when incorporating dummy drift data into estimates of avian carcass loss. Further, none of the avian carcasses and dummies released more than 40 km from the shoreline made it to shore. In the northern Gulf of Mexico, carcasses that die on the waters farther offshore are unlikely to make it to shore to be captured in a deposition model; therefore, it may be appropriate to utilize a separate methodology to estimate offshore mortality. The applicability of these results to other spill events should be evaluated in the context of the specific spill characteristics.

Severe and malignant hypertension are common in primary atypical hemolytic uremic syndrome.

Malignant hypertension is listed among the causes of secondary thrombotic microangiopathy, but pathogenic mutations in complement genes have been reported in patients with hypertension-induced thrombotic microangiopathy. Here we investigated the frequency and severity of hypertension in 55 patients with primary atypical hemolytic uremic syndrome (aHUS). A genetic analysis was performed in all patients, and funduscopic examination was performed in all the patients with Grades 2 and 3 hypertension. A cohort of 110 patients with malignant hypertension caused by diseases other than aHUS served as control. Thirty-six patients with aHUS presented Grade 2 or Grade 3 hypertension and funduscopic examination showed malignant hypertension in 19. Genetic abnormalities in complement were found in 19 patients (37% among patients with malignant hypertension). Plasmapheresis was performed in 46 patients and 26 received eculizumab. Renal and hematological responses were significantly lower after plasmapheresis (24%) than after eculizumab (81%). Renal survival was significantly higher in patients treated with eculizumab (85% at one, three and five years) compared to patients who did not receive this treatment (54%, 46% and 41%), respectively. Response to eculizumab was independent of hypertension severity and the presence of complement genetic abnormalities. Among patients with malignant hypertension caused by other diseases the prevalence of thrombotic microangiopathy was very low (5%). Thus, severe and malignant hypertension are common among patients with aHUS and eculizumab treatment leads to a higher renal survival when compared to plasmapheresis. However, thrombotic microangiopathy is uncommon among patients presenting with malignant hypertension caused by diseases other than aHUS.

ß-Arrestin-1 mediates the TCR-triggered re-routing of distal receptors to the immunological synapse by a PKC-mediated mechanism.

T-cell receptors (TCR) recognize their antigen ligand at the interface between T cells and antigen-presenting cells, known as the immunological synapse (IS). The IS provides a means of sustaining the TCR signal which requires the continual supply of new TCRs. These are endocytosed and redirected from distal membrane locations to the IS. In our search for novel cytoplasmic effectors, we have identified ß-arrestin-1 as a ligand of non-phosphorylated resting TCRs. Using dominant-negative and knockdown approaches we demonstrate that ß-arrestin-1 is required for the internalization and downregulation of non-engaged bystander TCRs. Furthermore, TCR triggering provokes the ß-arrestin-1-mediated downregulation of the G-protein coupled chemokine receptor CXCR4, but not of other control receptors. We demonstrate that ß-arrestin-1 recruitment to the TCR, and bystander TCR and CXCR4 downregulation, are mechanistically mediated by the TCR-triggered PKC-mediated phosphorylation of ß-arrestin-1 at Ser163. This mechanism allows the first triggered TCRs to deliver a stop migration signal, and to promote the internalization of distal TCRs and CXCR4 and their translocation to the IS. This receptor crosstalk mechanism is critical to sustain the TCR signal.

Secreted herpes simplex virus-2 glycoprotein G modifies NGF-TrkA signaling to attract free nerve endings to the site of infection.

Herpes simplex virus type 1 (HSV-1) and HSV-2 are highly prevalent viruses that cause a variety of diseases, from cold sores to encephalitis. Both viruses establish latency in peripheral neurons but the molecular mechanisms facilitating the infection of neurons are not fully understood. Using surface plasmon resonance and crosslinking assays, we show that glycoprotein G (gG) from HSV-2, known to modulate immune mediators (chemokines), also interacts with neurotrophic factors, with high affinity. In our experimental model, HSV-2 secreted gG (SgG2) increases nerve growth factor (NGF)-dependent axonal growth of sympathetic neurons ex vivo, and modifies tropomyosin related kinase (Trk)A-mediated signaling. SgG2 alters TrkA recruitment to lipid rafts and decreases TrkA internalization. We could show, with microfluidic devices, that SgG2 reduced NGF-induced TrkA retrograde transport. In vivo, both HSV-2 infection and SgG2 expression in mouse hindpaw epidermis enhance axonal growth modifying the termination zone of the NGF-dependent peptidergic free nerve endings. This constitutes, to our knowledge, the discovery of the first viral protein that modulates neurotrophins, an activity that may facilitate HSV-2 infection of neurons. This dual function of the chemokine-binding protein SgG2 uncovers a novel strategy developed by HSV-2 to modulate factors from both the immune and nervous systems.

Herpes simplex virus particles interact with chemokines and enhance cell migration.

Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2, respectively) are among the most prevalent human pathogens, causing a variety of diseases. HSV modulation of the chemokine network remains poorly understood. We have previously identified secreted glycoprotein G (SgG) as the first viral chemokine-binding protein that enhances chemokine function as a novel viral immunomodulatory mechanism. However, gG is also present at the viral envelope and its role in the virus particle remains unknown. Here we have addressed the chemokine-binding capacity of HSV particles and the functionality of such interaction in vitro. We adapted surface plasmon resonance assays and demonstrated the ability of HSV particles to bind a specific set of human chemokines with high affinity. Moreover, we identified gG as the envelope glycoprotein mediating such interaction, as shown by the lack of binding to a HSV-1 gG mutant. In contrast to HSV-1, HSV-2 gG is cleaved and the chemokine-binding domain is secreted (SgG2). However, we found that HSV-2 particles retain the ability to bind chemokines, potentially through SgG2 associated to the viral envelope or non-processed precursor protein. Moreover, we found that HSV particles increase cell migration independently of chemokine binding to envelope gG. This work provides insights into HSV manipulation of the host immune system.

Enhancement of chemokine function as an immunomodulatory strategy employed by human herpesviruses.

Herpes simplex virus (HSV) types 1 and 2 are highly prevalent human neurotropic pathogens that cause a variety of diseases, including lethal encephalitis. The relationship between HSV and the host immune system is one of the main determinants of the infection outcome. Chemokines play relevant roles in antiviral response and immunopathology, but the modulation of chemokine function by HSV is not well understood. We have addressed the modulation of chemokine function mediated by HSV. By using surface plasmon resonance and crosslinking assays we show that secreted glycoprotein G (SgG) from both HSV-1 and HSV-2 binds chemokines with high affinity. Chemokine binding activity was also observed in the supernatant of HSV-2 infected cells and in the plasma membrane of cells infected with HSV-1 wild type but not with a gG deficient HSV-1 mutant. Cell-binding and competition experiments indicate that the interaction takes place through the glycosaminoglycan-binding domain of the chemokine. The functional relevance of the interaction was determined both in vitro, by performing transwell assays, time-lapse microscopy, and signal transduction experiments; and in vivo, using the air pouch model of inflammation. Interestingly, and in contrast to what has been observed for previously described viral chemokine binding proteins, HSV SgGs do not inhibit chemokine function. On the contrary, HSV SgGs enhance chemotaxis both in vitro and in vivo through increasing directionality, potency and receptor signaling. This is the first report, to our knowledge, of a viral chemokine binding protein from a human pathogen that increases chemokine function and points towards a previously undescribed strategy of immune modulation mediated by viruses.

Indications of Induction and Caesarean Sections Performed Using the Robson Classification in a University Hospital in Spain from 2010 to 2021.

Background: The Robson Ten Group Classification System (RTGCS) enables the assessment, monitoring, and comparison of caesarean section rates both within healthcare facilities and between them, and the indications of caesarean sections (CS) performed in a maternity ward. The aims of the present study were to conduct an analysis to assess the levels and distribution of birth from a descriptive approach by CS in La Ribera University Hospital (Spain) between 2010-2021 using the Robson classification; to describe the indications for the induction of labour and the causes of caesarean sections performed; and to examine the association between the induction of labour and CS birth. Methods: A retrospective study between 1 January 2010 and 31 December 2021. All eligible women were classified according to the RTGCS to determine the absolute and relative contribution by each group to the overall CS rate. The odds ratio (OR) of the variables of interest was estimated by logistic regression. In an analysis of the subgroups, the level of significance was adjusted using the Bonferroni method. Results: 20,578 women gave birth during the study period, 19% of them by CS. In 33% of births, induction was performed, and the most common cause was the premature rupture of membranes. Group 2 (nulliparous with induced labour/elective CS before labour) accounted for the largest contribution to the overall rate of CS (31.5%) and showed an upward trend from 23.2% to 39.7% in the time series, increasing the CS rate by 6.7%. The leading cause of CS was suspected fetal distress, followed by induction failure. Conclusions: In our study, Robson Group 2 was identified as the main contributor to the hospital's overall CS rate. Determining the causes of induction and CS in a population sample classified using the RTGCS enables the identification of the groups with the greatest deviation from the optimal rate of CS and the establishment of improvement plans to reduce the overall rate of caesarean sections in the maternity unit.

Autosomal dominant polycystic kidney disease in young adults.

Background: The clinical manifestations of autosomal dominant polycystic kidney disease (ADPKD) usually appear in adulthood, however pediatric series report a high morbidity. The objective of the study was to analyze the clinical characteristics of ADPKD in young adults. Methods: Family history, hypertension, albuminuria, estimated glomerular filtration rate (eGFR) and imaging tests were examined in 346 young adults (18-30 years old) out of 2521 patients in the Spanish ADPKD registry (REPQRAD). A literature review searched for reports on hypertension in series with more than 50 young (age <30 years) ADPKD patients. Results: The mean age of this young adult cohort was 25.24 (SD 3.72) years. The mean age at diagnosis of hypertension was 21.15 (SD 4.62) years, while in the overall REPQRAD population was aged 37.6 years. The prevalence of hypertension was 28.03% and increased with age (18-24 years, 16.8%; 25-30 years, 36.8%). Although prevalence was lower in women than in men, the age at onset of hypertension (21 years) was similar in both sexes. Mean eGFR was 108 (SD 21) mL/min/1.73 m2, 38.0% had liver cysts and 3.45% of those studied had intracranial aneurysms. In multivariate analyses, hematuria episodes and kidney length were independent predictors of hypertension (area under the curve 0.75). The prevalence of hypertension in 22 pediatric cohorts was 20%-40%, but no literature reports on hypertension in young ADPKD adults were found. Conclusions: Young adults present non-negligible ADPKD-related morbidity. This supports the need for a thorough assessment of young adults at risk of ADPKD that allows early diagnosis and treatment of hypertension.