Human Type Research Articles

Zein-based nanostructured coatings: A green approach to enhance virucidal efficacy of protective face masks.

Face masks represent a valuable tool to prevent the spreading of airborne viruses; however, they show poor comfort and scarce antiviral efficacy. Zein-based coatings are herein exploited to enhance antiviral performance. Zein functionalization is done through acidifying agents (lactic acid, LA). Coatings are characterized in terms of morphological, mechanical, breathability, and cytotoxicity analyses. The antiviral efficacy is tested in vitro against four viruses (Human Coronavirus OC43, Herpes Simplex Virus type 1, Human Adenovirus type 5, and MPox Virus) according to a biological assay on cell cultures. Zein/Zein LA antiviral activity seems to be linked to its positive surface charge that enables to form electrostatic interactions with negatively charged-viruses, resulting in the highest activity (reduction >2 Log) on Human Coronavirus OC43 and Herpes Simplex Virus type 1, with efficacy comparable or higher than that of copper/copper oxide-based- coatings. No significant activity is observed against Human Adenovirus type 5 and MPox Virus, due to their high resistance to inactivating treatments. Zein-based systems are not cytotoxic and their water vapor permeability is reduced of 26% compared to that of not-coated systems. These promising results offer interesting insights into design of antiviral and sustainable coatings for personal protective equipment.

NRG-GI007: Secondary endpoints of safety assessment and clinical complete response (cCR) of chemoradiation with endoscopically injected oncolytic virus OBP-301 in medically inoperable esophageal cancer.

435 Background: Definitive chemoradiation (CRT) is a standard-of-care for patients (Pts) with medically inoperable esophageal cancer (EC). The NRG/RTOG 0436 study of cisplatin/paclitaxel and RT (+/- cetuximab) as definitive therapy showed that 58% of control arm Pts have locally persistent disease. OBP-301 is a conditionally-restricted, replication-competent adenovirus derived from human adenovirus type 5 that adds a human Telomerase Reverse Transcriptase gene promoter, replicating only in tumor cells to cause lysis.It may cause immunogenic cell death, enhance RT increasing radiosensitization by blocking DNA repair and improve local control. Methods: In NRG-GI007, a phase 1 study (NCT04391049), OBP-301 was added to weekly carboplatin/paclitaxel and RT (50.4 Gy/28 fxs) for medically inoperable EC Pts with pathologically proven adenocarcinoma or squamous cell carcinoma (SCC) of the esophagus or Siewert Type I/II gastroesophageal junction. Pts receive 1-2mL of intratumoral OBP-301 1×10 12 virus particles/ml via endoscopy 3 days prior to and then at days 12 and 26 of CRT. The primary endpoint was protocol-defined dose-limiting toxicity, already reported. Secondary endpoints reported here are treatment-related (definitely or probably related to any protocol treatment) AEs - all and grade 4+ non-hematologic, and cCR in the primary tumor, defined as negative EGD/biopsy 6-8 weeks post-CRT. Per the protocol design, no statistical testing is done for these endpoints. Results: Initially, 6 evaluable (eligible and started protocol treatment) Pts were enrolled from June 2020 to April 2023. As initial dose level was deemed safe, an additional 9 Pts were enrolled from August 2023 to July 2024, totaling 15 evaluable Pts for secondary endpoints. Median age was 74 years, 9 Pts (60%) with ECOG PS 1. 11 Pts (73%) had adenocarcinoma and 4 had SCC; 11 Pts had N+ disease. 14 Pts (93%) received all planned OBP-301 injections and received 50.4 Gy RT. The most common treatment-related grade 3/4 AEs were decreased neutrophil (6 Pts; 40%) and lymphocyte counts (5 Pts; 33%), expected with CRT. No grade ≥3 OBP-301-related non-hematologic AEs were reported. 2 Pts died prior to restaging neitherdefinitely or probably related to OBP-301: 1 Pt developed grade 5 respiratory failure 6 weeks after CRT (suspected RT pneumonitis), while a 2 nd Pt had an unrecognized tumor invasion of the bronchus at baseline, which worsened during week 3 of CRT, resulting in a grade 5 tracheo-esophageal fistula. 2 Pts have not yet reached time for restaging. All 11 Pts who have been restaged had a cCR, for a preliminary cCR rate of 100% (95% CI: 74.1%, 100%). Conclusions: OBP-301 + CRT is safe and the preliminary cCR rate compares favorably to the historical control from NRG/RTOG 0436. Updated safety and cCR data will be presented. A randomized study is being planned. Clinical trial information: NCT04391049 .

Acute Encephalopathy Associated with Human Adenovirus Type 14 Infection in 7-Year-Old Girl, Japan

Acute Encephalopathy Associated with Human Adenovirus Type 14 Infection in 7-Year-Old Girl, Japan

Virus-host immune interaction in asymptomatic HTLV-1 carriers.

Human T-cell leukemia virus type 1 (HTLV-1) can cause fatal diseases, including adult T-cell leukemia in humans after long-term asymptomatic infection. In asymptomatic HTLV-1 carriers, substantial proviruses are detectable in lymphocytes, and the association of a higher proviral load with a higher risk of disease progression has been observed. However, viral replication is controlled and HTLV-1 production is poor in asymptomatic carriers. Virus-host immune interaction during latent infection has not been fully determined. In the present study, virus-specific antibody and T-cell responses in asymptomatic HTLV-1 carriers were investigated. Neutralizing antibody responses were positively correlated with proviral loads. Tax-specific CD8+ T-cell frequencies were not associated with proviral loads but inversely correlated with the ratios of p19-expressing CD4+ T-cell frequencies to proviral loads, supporting the notion that Tax-specific CD8+ T-cell responses play an important role in the control of HTLV-1 replication. These results provide insights into the mechanism of virus-host immune interaction in latent HTLV-1 infection.

Injection of Different Concentrations of Recombinant Humanized Type III Collagen Into the Dermis Promotes Type III and Type I Collagen Deposition as Well as Angiogenesis: An In Vivo Study.

Type III recombinant humanized collagen (rhCol III) has a promising future in cosmetic applications. To investigate the histological changes associated with injection of different concentrations of Type III rhCol III into the dermis. Twenty mice were divided into a control, low-dose (LD) group, and high-dose (HD) group. The animals were euthanized 1, 2, 3, and 4 weeks after the injection. Injections of rhCol III induced an increase in collagen formation in a concentration-dependent manner. Type I collagen (Col I) was upregulated in both HD and LD groups to varying extents, often similar to that of Col III. Fibroblast proliferation plays an important role in the deposition of Col I and Col III. Injections of rhCol III promoted angiogenesis at later stages, regardless of concentration dependency. Intradermal injections of rhCol III can promote fibroblast proliferation, enhancing the deposition of both Col I and Col III, and stimulating angiogenesis. Further studies are required to elucidate the mechanisms.

Investigating The Circadian Rhythm Signaling Pathway in HTLV-1 Pathogenesis Using Boolean Analysis.

The Human T-cell lymphotropic virus type 1 (HTLV-1), an oncogenic virus belonging to the Deltaretrovirus genus, expresses various proteins, including Tax and HBZ, which can affect many cellular pathways. In this study, we have investigated the role of the circadian rhythm signaling pathway, a key regulator of human health, in the pathogenesis of HTLV-1 using Boolean Network analysis and laboratory methods. After an extensive search of the circadian rhythm pathway, we analyzed the relationships between the genes of this pathway using the R programming language and the BoolNet package. Subsequently, we examined the impact of viral proteins on the cellular clock rhythm genes. Finally, we identified three genes, PER2, CRY1, and DEC1, as the main checkpoints from the attractors obtained. These three genes and two viral genes, Tax and HBZ, were quantitatively assessed on two groups of individuals, including ten asymptomatic carriers infected with HTLV-1 and ten healthy individuals using the qRT-PCR method. Our results showed that the expression level of PER2 and DEC1 genes was significantly higher in the asymptomatic carriers compared to the healthy control group. Also, we recorded positive correlations between PER2 and DEC1, CRY1 and DEC1, and negative correlations between HBZ and CRY1 and DEC1. In this study, we suggested that in asymptomatic carriers, the virus might try to induce a chronic infection by escaping from the immune system due to an alteration in circadian rhythm pathways. We also detected three promising genes in this pathway that could have therapeutic or diagnostic value in these individuals. However, this possibility requires further research in different periods, different groups (e.g., ATLL and HAM/TSP), and examining a more significant number of circadian rhythm genes.

Comparative Analysis of Caco-2 Cells and Human Jejunal and Duodenal Enteroid-Derived Cells in Gel- and Membrane-Based Barrier Models of Intestinal Permeability.

Intestinal absorption is a key toxicokinetics parameter. While the colon carcinoma cell line Caco-2 is the most used in vitro model to estimate human drug absorption, models representing other intestinal segments are developed. We characterized the morphology, tissue-specific markers and functionality of three human intestinal cell types: Caco-2, primary human enteroid-derived cells from jejunum (J2), and duodenum (D109) when cultured in the OrganoPlate® 3-lane 40 microphysiological system (MPS) or static 24-well Transwells™. In both conditions, J2 and D109 formed dome-like structures; Caco-2 formed uniform monolayers. In MPS, only Caco-2 formed tubules. Cells grown on Transwells™ formed a thicker monolayer. All cells and conditions exhibited expression of ZO-1 (tight junctions). Polarization markers Ezrin and Villin were highest in J2 and D109 in MPS, highest expression of Mucin was observed with J2. However, J2 and D109 exhibited poor barrier (70 kDa TRITC-dextran) in MPS, while robust barrier was recorded in Transwells™. Barrier function and drug transport were evaluated using caffeine, indomethacin, and propranolol. The gel lane in MPS acted as a blockade; only a small fraction crossed, even without cells. The permeability ratios were used to parameterize the probabilistic compartmental absorption model to determine whether in vitro data could reduce uncertainty. The most accurate prediction of the fraction absorbed was achieved with Transwell™-derived data from Caco-2, combined with the experimentally-derived segment-specific absorption ratios. The impact of this study includes demonstration that enteroid-derived cells cultured in MPS show most physiological morphology, but that studies of drug permeability in this MPS are challenging.

CBX2 suppresses interferon signaling to diminish tumor immunogenicity via a noncanonical corepressor complex

Chromobox 2 (CBX2), a crucial component of the polycomb repressive complex (PRC), has been implicated in the development of various human cancers. However, its role in the regulation of tumor immunogenicity and immune evasion remains inadequately understood. In this study, we found that ablation of CBX2 led to tumor growth inhibition, activation of the tumor immune microenvironment, and enhanced therapeutic efficacy of anti-PD1 or adoptive T cell therapies by using murine syngeneic tumor models. By analysis of the CBX2-regulated transcriptional program coupled with mass spectrometry screening of CBX2-interacting proteins, we found that CBX2 suppresses interferon signaling independent of its function in the canonical PRC. Mechanistically, CBX2 directly interacts with RACK1 and facilitates the recruitment of HDAC1, which attenuates the H3K27ac modification on the promoter regions of interferon-stimulated genes, thereby suppressing interferon signaling. Consequently, CBX2 reduces tumor immunogenicity and enables immune evasion. Moreover, a high expression level of CBX2 is associated with immune suppressive tumor microenvironment and reduced efficacy of immunotherapy across various human cancer types. Our study identifies a noncanonical CBX2-RACK1-HDAC1 corepressor complex in suppression of tumor immunogenicity, thereby presenting a potential target and biomarker for tumor immunotherapy.

Extended receptor repertoire of an adenovirus associated with human obesity.

Human adenovirus type 36 (HAdV-D36) has been putatively linked to obesity in animals and has been associated with obesity in humans in some but not all studies. Despite extensive epidemiological research there is limited information about its receptor profile. We investigated the receptor portfolio of HAdV-D36 using a combined structural biology and virology approach. The HAdV-D36 fiber knob domain (FK), which mediates the primary attachment of many HAdVs to host cells, has a significantly elongated DG loop that alters known binding interfaces for established adenovirus receptors such as the coxsackie- and adenovirus receptor (CAR) and CD46. Our data suggest that HAdV-D36 attaches to host cells using a versatile receptor pool comprising sialic acid-containing glycans and CAR. Sialic acids are recognized at the same binding site used by other HAdVs of species D such as HAdV-D37. Using glycan microarrays, we demonstrate that HAdV-D36 displays a binding preference for glycans containing a rare sialic acid variant, 4-O,5-N-diacetylneuraminic acid, over the more common 5-N-acetylneuraminic acid. To date, this sialic acid variant has not been detected in humans, although it can be synthesized by various animal species, including a range of domestic and livestock animals. Taken together, our results indicate that HAdV-D36 has evolved to recognize a specialized set of primary attachment receptors that are different from known HAdV types and coincides with a unique host range and pathogenicity profile.

Identification of near full-length human pegivirus type 2 (HPgV-2) genomes in blood donor samples co-infected with hepatitis C virus (HCV).

Human pegivirus (HPgV) identified from an HCV-infected plasma sample through nanopore metagenomics. The analysis revealed a nearly complete HPgV-2 genome. Phylogenetic analysis confirmed its classification within the HPgV-2 genotype, providing insights into viral co-infection dynamics. The metagenomics approach advances the understanding of viral diversity and supports the development of accurate diagnostics.

P-994. Cellular and humoral immunological profile of Human T-Lymphotropic Virus type I (HTLV-1) in a pediatric case series

Abstract Background Human T- lymphotropic Virus type 1 (HTLV-1) is a powerful oncovirus. In South America there is a high incidence of cases in countries such as Brazil, Peru and Colombia, mainly affecting the indigenous and Afro-descendant population. In children, the main clinical findings are dermatological manifestations followed by lung disease, opportunistic coinfections, and autoinflammatory disorders. The main target of HTLV-1 is CD4+ T lymphocytes, which are the regulators of the acquired immune response, but It’s also capable of infecting CD8+ T lymphocytes, B cells, dendritic cells and synovial cells. The purpose of this study is to describe the humoral and cellular immunological profile in pediatric patients diagnosed with HTLV-1 in a reference center in Cali, Colombia.Table 1.Characterization of cellular immunity in pediatric patients diagnosed with HTLV1 (n = 6)BL: B lymphocyte, TL: T lymphocyte Source: Self elaboration Methods This is an observational, descriptive, retrospective cross-sectional study carried out between January 2017 and March 2021.Table 2.Characterization of humoral immunity in pediatric patients diagnosed with HTLV1 (n = 16) Results Nineteen patients were included in this study with a median age at diagnosis of 94 months, most of them were schoolchildren (52.6%), 50% of patients had elevated B lymphocytes (CD19), and 50% of them had normal range cytotoxic T lymphocytes (CD8+) and helper T lymphocytes (CD4) (Table 1 and graph 1). None of the patients had decreases in serum immunoglobulins (IgM, IgG, IgE and IgA) (Table 2 and graph 2)Graph 1.Cellular immunological profile (n=6) Conclusion HTLV-1 immunosuppression is not mediated by low levels of lymphocyte subpopulations in the pediatric population.Graph 2.Humoral immunological profile (n=16) Disclosures All Authors: No reported disclosures

P-162. Estimating the Seroprevalence of HTLV-1 in Pregnant Peruvian Women Based on Blood Bank Markers: a Road to Elimination of Mother-to-Child Transmission of HTLV-1

Abstract Background The prevention of mother-to-child transmission (PMTCT) of human T-cell lymphotropic virus type 1 (HTLV-1) is a top priority for HTLV-endemic countries due to its chronicity, lack of treatment and association with the aggressive adult T cell leukemia/lymphoma in comparison to other routes of infection. As of 2024, Japan, Brazil and Chile are few of the countries with national policies regarding antenatal screening. Peru, also an endemic country with around 150,000 to 450,000 HTLV-1 carriers, has limited data in pregnant women and does not have any PMTCT policy in place. By contrast, HTLV-1/2 antibody screening of blood donations has been endorsed since 1997 and national data are available. We aim to leverage these data to estimate the prevalence of HTLV-1 in pregnant women as a first step towards development and implementation of a PMTCT policy in Peru. Figure 1 Estimation of number of HTLV-1 infected pregnant women and HTLV-1 seroprevalence in pregnant women in Peru (2017) Methods This was an ecological study using public-use data from the Peruvian Bulletin on Blood Supply 2015-2020, the 2017 National Census, the 2017 Demographic and Health Survey (DHS) and the National Registry. The unit of analysis was Peru and its subregions in the year of 2017. To estimate the number of infected women of reproductive age (WRA, 15-49 years), we used census data and a calculated percentage of HTLV-1/2 reactive blood units for this group based on a weighted factor by sex and age (Figure 1, Table 1). Using the DHS percentage of WRA currently pregnant, we estimated the number of infected pregnant women. To obtain the HTLV-1 prevalence for this group, we used the number of life births adjusted for a 9-month period (0.75) as the denominator. Calculation of weighted factor for HTLV-1/2 seroprevalence by age and sex based on local blood bank data Results A total of 359,458 blood units were screened and 2,809 were reactive for HTLV-1/2 (0.78%) (Figure 2). We estimated between 68,456 to 72,978 HTLV-1 carriers who were WRA, of whom 2,463 to 2,773 were pregnant (Figure 3). This is comparable to rates in Japan and Brazil. Our estimated HTLV-1 seroprevalence in pregnant women was 0.61% for the entire country. Number and percentage of HTLV-1/2 reactive blood units in 2017 by departments of Peru Conclusion Our findings could help guide future strategies for PMTCT, such as universal antenatal screening and assessing the feasibility of formula supplementation for infants born to HTLV-1 positive mothers. Our limitations included the use of one-year data, HTLV-1/2 false-positives in blood donors and not using inverse probability weighting. Estimated number and percentage of HTLV-1 infected pregnant women in 2017 by Departments of Peru Disclosures All Authors: No reported disclosures

P-672. Coinfections with Respiratory Syncytial Virus (RSV) in a Cohort of Adults with Pre-Existing Comorbidities in Wisconsin from 2015-16 through 2019-20

Abstract Background Current evidence suggests that coinfections with respiratory syncytial virus (RSV) may affect symptom and disease severity during acute respiratory infection (ARI). However, this data is largely observed in children, with limited data regarding RSV coinfections in adults with pre-existing comorbidities.Table 1.Demographic and clinical characteristics among high-risk adults with RSV coinfection and RSV single infection from 2015-16 through 2019-20 respiratory virus seasons. Methods We conducted a retrospective cohort study, using existing data and respiratory specimens from community-dwelling adult participants in a test-negative study of influenza vaccine effectiveness. The study was conducted in an outpatient setting in Wisconsin from 2015-2016 through 2019-2020. Participants included in this analysis had ≥1 pre-existing comorbidity (Table 1). Residual respiratory specimens were retested using a PCR-based multiplex panel for adenovirus (HAdV), seasonal coronaviruses (HCoV), human metapneumovirus, rhinovirus/enterovirus (HRV), influenza virus (IFV) (influenza A H1pdm09, H3, and B), human parainfluenza virus types 1-4, RSV A and B. RSV coinfection was defined as the detection of two or more pathogens, one of which was RSV A or B and the other non-RSV. We used chi-square tests to compare demographic and clinical characteristics between those with RSV coinfection vs. RSV single infection. Results Of 3601 respiratory samples from high-risk adults tested, RSV coinfection was detected in 18 (0.5%) participants and RSV single infection in 285 (7.9%). RSV coinfections occurred with HRV (8; 44.4%); IFV (6; 33.3%); HCoV (5; 27.8%); and HAdV (1; 5.6%), and was highest among those aged 18-49 years (9; 50%). We did not observe statistically significant differences between coinfections vs. single infections by presence of upper or lower respiratory symptoms, or by high-risk conditions (Table 1). Hospitalization occurred only in individuals with RSV single infections (10, 3.5%). Conclusion RSV viral co-infections were detected in 0.5% of 3601 respiratory samples of high-risk adults, including coinfections with HRV, IFV, HCoV and HAdV. We did not observe significant differences in symptoms between those with RSV coinfection vs single infection, however, hospitalization occurred only in individuals with RSV single infection. Limitations of this analysis include its sample size and the restrictions of multiplex assay sensitivity and specificity. Disclosures Oluwakemi Alonge, MPH, CPH, CSL Seqirus: Grant/Research Support|GSK Inc.: Grant/Research Support Maria Sundaram, PhD, MSPH, GSK Inc.: Grant/Research Support|Pfizer Inc.: Grant/Research Support Huong Nguyen, PhD, MPH, CSL Seqirus: Advisor/Consultant|CSL Seqirus: Grant/Research Support|GSK: Grant/Research Support|ModernaTX: Advisor/Consultant|ModernaTX: Grant/Research Support Jennifer P. King, MPH, GSK Inc.: Grant/Research Support|ModernaTX: Grant/Research Support Elisha Stefanski, BS, CSL Seqirus: Grant/Research Support|GSK Inc.: Grant/Research Support|ModernaTX: Grant/Research Support Pouya Saeedi, PhD., GSK: Employment Yves Brabant, MEng, GSK: Employed Jean-Yves Pirçon, PhD, GSK Inc.: Employment

SSL-VQ: Vector-quantized variational autoencoders for semi-supervised prediction of therapeutic targets across diverse diseases.

Identifying effective therapeutic targets poses a challenge in drug discovery, especially for uncharacterized diseases without known therapeutic targets (e.g. rare diseases, intractable diseases). This study presents a novel machine learning approach employing multimodal vector-quantized variational autoencoders (VQ-VAEs) for predicting therapeutic target molecules across diseases. To address the lack of known therapeutic target-disease associations, we incorporate the information on uncharacterized diseases without known targets or uncharacterized proteins without known indications (applicable diseases) in the semi-supervised learning (SSL) framework. The method integrates disease-specific and protein perturbation profiles with genetic perturbations (e.g., gene knockdowns and gene overexpressions) at the transcriptome level. Cross-cell representation learning, facilitated by VQ-VAEs, was performed to extract informative features from protein perturbation profiles across diverse human cell types. Concurrently, cross-disease representation learning was performed, leveraging VQ-VAE, to extract informative features reflecting disease states from disease-specific profiles. The model's applicability to uncharacterized diseases or proteins is enhanced by considering consistency between disease-specific and patient-specific signatures. The efficacy of the method is demonstrated across three practical scenarios for 79 diseases: target repositioning for target-disease pairs, new target prediction for uncharacterized diseases, and new indication prediction for uncharacterized proteins. This method is expected to be valuable for identifying therapeutic targets across various diseases. Code: github.com/YamanishiLab/SSL-VQ & Data: 10.5281/zenodo.14644837. Supplementary data are available at Bioinformatics online.

The Characteristics and Functions of Orally Absorbed Herbal Decoction-borne Plant MicroRNAs.

Herbal decoctions always contain numerous plant microRNAs (miRNAs), and some of these can be absorbed orally to exert cross-kingdom gene regulation. However, little is known about which specific types of herbal decoction-borne plant miRNAs are more likely to be absorbed. Thus, two antiviral herbal decoctions, Qingfei Paidu (QFPD) and Qingre Huashi Kangdu (QRHS), were administered to human volunteers and rats, respectively, to investigate the characteristics of orally absorbed decoction-borne plant miRNAs. MIR-6240-3p was identified as an absorbed plant miRNA in humans and is most highly expressed in QFPD decoction. Therefore, the kinetics of MIR-6240-3p were monitored in humans following the administration of the QFPD decoction, and its antiviral effect on human coronavirus type 229E (HCoV-229E) was examined in vitro. 586,176 small RNAs (sRNAs) were identified in QFPD decoction, of which 100,276 were orally absorbed by humans. In the QRHS decoction, 124,026 sRNAs were detected, with 7484 being orally absorbed by rats. Logistical repression analysis revealed that absorbable plant sRNAs in both humans and rats presented higher expression levels, greater minimum free energy, and increased AU/UA frequencies compared to non-absorbable plant sRNAs. The amount of MIR-6240-3p in humans increased between 1- and 3-hours after the administration of the QFPD decoction. In addition, MIR-6240-3p significantly reduced the RNA copy number and TCID50 of HCoV-229E in vitro. These results suggest that herbal decoction-borne plant sRNAs with higher expression level, greater minimum free energy or an increased AU/UA frequency are more likely to be orally absorbed and could potentially mediate cross-kingdom gene regulation.

M-Sec promotes the accumulation of intracellular HTLV-1 Gag puncta and the incorporation of Env into viral particles.

We have demonstrated that the cellular protein M-Sec promotes the transmission of human T-cell leukemia virus type 1 (HTLV-1) in vitro and in vivo. Here, we show how HTLV-1 utilizes M-Sec for its efficient transmission. HTLV-1-infected CD4+ T cells expressed M-Sec at a higher level than uninfected CD4+ T cells. The ex vivo culture of the infected cells upregulated the expression of M-Sec, the level of which was sustained for a long time. The viral structural protein Gag is distributed in a punctate pattern in cells. M-Sec promoted the accumulation of large intracellular Gag puncta. This accumulation was dependent on phosphatidylinositol 4,5-bisphosphate (PIP2), since it was lost upon the removal of PIP2 binding motifs in M-Sec or the depletion of cellular PIP2. The viral envelope protein Env co-localized with the large Gag puncta induced by M-Sec. Furthermore, viral particles produced by M-Sec-expressing cells contained a higher amount of Env. Given that M-Sec alters the cellular distribution of PIP2, these results suggest that M-Sec promotes the formation of infectious viral particles through PIP2. Since the expression of M-Sec is mediated by HTLV-1 Tax protein, M-Sec appears to function in a positive feedback loop that ensures efficient HTLV-1 transmission.

The Combination of GS-441524 (Remdesivir) and Ribavirin Results in a Potent Antiviral Effect Against Human Parainfluenza Virus 3 Infection in Human Airway Epithelial Cell Cultures and in a Mouse Infection Model

Human parainfluenza virus type 3 (HPIV-3) can cause severe respiratory diseases, particularly in young children, the elderly and immunocompromised. There are no approved antiviral drugs against this virus. We report that the combination of ribavirin with either remdesivir or its parent nucleoside GS-441524 results in a pronounced antiviral effect against HPIV-3 in LLC-MK2 cells and in human airway epithelial cells grown at the air–liquid interface. In AG129 mice intranasally inoculated with HPIV-3, the combined treatment with ribavirin and GS-441524 decreased infectious viral lung titers by >2.5 log10 to undetectable levels in 4 out of 11 mice and by 1.6 log10 in the remaining 7 mice as compared with the vehicle. The lungs of all mice that received the combined treatment appeared histologically normal or virtually normal, whereas 8 of 11 vehicle-treated mice presented with bronchopneumonia. By contrast, ribavirin alone did not result in a reduction in infectious viral lung titers; GS-441524 alone reduced infectious viral lung titers by 1.2 log10. Moreover, several mice in the single-treatment groups exhibited severe lung pathology. These findings may warrant exploring this combination in patients with severe HPIV-3 infections and possibly also against infections with other viruses that are susceptible in vitro to these two drugs.

Electrophysiological properties of vestibular hair cells isolated from human crista

IntroductionThe vast majority of cellular studies on mammalian vestibular hair cells have been carried out in rodent models due in part to the inaccessibility of human inner ear organs and reports describing electrophysiological recordings from human inner ear sensory hair cells are scarce. Here, we obtained freshly harvested vestibular neuroepithelia from adult translabyrinthine surgical patients to obtain electrophysiological recordings from human hair cells.MethodsWhole cell patch clamp recordings were performed on hair cells mechanically isolated from human cristae to characterize voltage-dependent and pharmacological properties of membrane currents. Hair cells were classified as type I or type II according to morphological characteristics and/or their electrophysiological properties.ResultsType I hair cells exhibited low voltage-activated K+ currents (IKLV) at membrane potentials around the mean resting membrane potential (-63 mV) and large slowly activating outward K+ currents in response to depolarizing voltage steps. Recordings from type II hair cells revealed delayed rectifier type outward K+ currents that activated above the average resting potential of -55 mV and often showed some inactivation at more depolarized potentials. Perfusion with the K+ channel blocker 4-aminopyridine (1 mM) substantially reduced outward current in both hair cell types. Additionally, extracellular application of 8-bromo-cGMP inhibited IKLV in human crista type I hair cells suggesting modulation via a nitric oxide/cGMP mechanism. A slow hyperpolarization-activated current (Ih) was observed in some hair cells in response to membrane hyperpolarization below -100 mV.DiscussionIn summary, whole cell recordings from isolated human hair cells revealed ionic currents that strongly resemble mature current phenotypes previously described in hair cells from rodent vestibular epithelia. Rapid access to surgically obtained adult human vestibular neuroepithelia allows translational studies crucial for improved understanding of human peripheral vestibular function.

DOP132 An integrated single-cell atlas enables the discovery and validation of a novel candidate therapeutic target for Inflammatory Bowel Disease

Abstract Background Single-cell technologies enable the fine mapping of disease and treatment mechanisms in inflammatory bowel disease (IBD). We sought to leverage these insights to discover novel drug targets with precise therapeutic hypotheses. To this end, we previously constructed one of the largest integrated single-cell atlas of IBD patient-derived tissue samples1. We then used Immunai’s ImmunoDynamics EngineTM, a proprietary machine learning (ML) framework, to identify transcriptional signatures of inflammation and non-response to anti-TNF treatment in specific cell populations, and extracted a ranked gene list that was highly enriched in targets of currently marketed IBD therapies. We selected top-ranked genes for in vitro functional genomic validation and leveraged the IBD single-cell atlas to support clinical relevance of in vitro observations. Here, we present a target case study demonstrating this approach. Methods The top 400 genes were triaged to choose 20 candidate targets based on novelty, druggability, genetic association with IBD, and experimental feasibility. Each of these 20 targets was individually deleted under optimized culture conditions in the primary human cell type(s) in which it showed a significant disease association in the IBD single-cell atlas, including monocyte-derived macrophages (MDM), CD8, CD4 helper and/or regulatory T cells, and intestinal fibroblasts. Knockout (KO) cells were characterized by flow cytometry, secreted proteome profiling, and bulk transcriptomics, with suitable positive and negative controls per cell type. KO-induced transcriptomic changes were interpreted via gene-set enrichment of canonical pathways and of IBD-associated transcriptional signatures derived from orthogonal clinical cohorts. KO-induced transcriptomic signatures were also computed in each sample in the IBD single-cell atlas. Results Deletion of one selected target in MDMs led to a reduction in TNFα and IFNγ signaling and in the expression of IBD inflammation-associated signatures from orthogonal patient cohorts. Genes downregulated by the deletion of this target in MDMs were enriched in macrophages from inflamed tissue in the IBD single-cell atlas. Conclusion The functional genomic data indicate that deletion of the selected target shifts MDMs away from a disease-associated inflammatory state, suggesting that its pharmacologic inhibition in macrophages may have a therapeutic benefit. These findings highlight the relevance of cell type-specific methods to understand disease mechanisms and characterize putative novel targets. Applying these experimental and clinical contextualization methods to additional candidate genes will further expand the basis for novel therapeutic strategies in IBD.

A network-based systems genetics framework identifies pathobiology and drug repurposing in Parkinson’s disease

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder. However, current treatments only manage symptoms and lack the ability to slow or prevent disease progression. We utilized a systems genetics approach to identify potential risk genes and repurposable drugs for PD. First, we leveraged non-coding genome-wide association studies (GWAS) loci effects on five types of brain-specific quantitative trait loci (xQTLs, including expression, protein, splicing, methylation and histone acetylation) under the protein–protein interactome (PPI) network. We then prioritized 175 PD likely risk genes (pdRGs), such as SNCA, CTSB, LRRK2, DGKQ, and CD44, which are enriched in druggable targets and differentially expressed genes across multiple human brain-specific cell types. Integrating network proximity-based drug repurposing and patient electronic health record (EHR) data observations, we identified Simvastatin as being significantly associated with reduced incidence of PD (hazard ratio (HR) = 0.91 for fall outcome, 95% confidence interval (CI): 0.87–0.94; HR = 0.88 for dementia outcome, 95% CI: 0.86–0.89) after adjusting for 267 covariates. In summary, our network-based systems genetics framework identifies potential risk genes and repurposable drugs for PD and other neurodegenerative diseases if broadly applied.