Enhanced broad spectrum in vitro antiviral efficacy of 3-F-4-MeO-Bn, 3-CN, and 4-CN derivatives of lipid remdesivir nucleoside monophosphate prodrugs.

Broad spectrum oral antivirals are urgently needed for the early treatment of many RNA viruses of clinical concern. We previously described the synthesis of 1-O-octadecyl-2-O-benzyl-glycero-3-phospho-RVn (V2043), an orally bioavailable lipid prodrug of remdesivir nucleoside (RVn, GS-441524) with broad spectrum antiviral activity against viruses with pandemic potential. Here we compared the relative activity of V2043 with new RVn lipid prodrugs containing sn-1 alkyl ether or sn-2 glycerol modifications. We found that 3-F-4-MeO-Bn, 3-CN-Bn, and 4-CN-Bn sn-2 glycerol modifications improved antiviral activity compared to V2043 when tested in vitro against clinically important RNA viruses from 5 virus families. These results support the continued development of V2043 and sn-2 glycerol modified RVn lipid prodrugs for the treatment of a broad range of RNA viruses for which there are limited therapies.

1-O-Octadecyl-2-O-benzyl-sn-glyceryl-3-phospho-GS-441524 (V2043). Evaluation of Oral V2043 in a Mouse Model of SARS-CoV-2 Infection and Synthesis and Antiviral Evaluation of Additional Phospholipid Esters with Enhanced Anti-SARS-CoV-2 Activity.

Early antiviral treatments, including intravenous remdesivir (RDV), reduce hospitalization and severe disease caused by COVID-19. An orally bioavailable RDV analog may facilitate earlier treatment of non-hospitalized COVID-19 patients. Here we describe the synthesis and evaluation of alkyl glyceryl ether phosphodiesters of GS-441524 (RVn), lysophospholipid analogs which allow for oral bioavailability and stability in plasma. Oral treatment of SARS-CoV-2-infected BALB/c mice with 1-O-octadecyl-2-O-benzyl-sn-glyceryl-3-phospho-RVn (60 mg/kg orally, once daily for 5 days starting 12h after infection) reduced lung viral load by 1.5 log10 units versus vehicle at day 2 and to below the limit of detection at day 5. Structure/activity evaluation of additional analogs that have hydrophobic ethers at the sn-2 of glycerol revealed improved in vitro antiviral activity by introduction of a 3-fluoro-4-methoxy-substituted benzyl or a 3- or 4-cyano-substituted benzyl. Collectively, our data support the development of RVn phospholipid prodrugs as oral antiviral agents for prevention and treatment of SARS-CoV-2 infections.

Synergistic inhibition of hepatitis C virus infection by a novel microtubule inhibitor in combination with daclatasvir.

Even though substantial progress has been made in the treatment of hepatitis C virus (HCV) infection, viral resistance and relapse still occur in some patients and additional therapeutic approaches may ultimately be needed should viral resistance become more prevalent. Microtubules play important roles in several HCV life cycle events, including cell attachment, entry, cellular transportation, morphogenesis and progeny secretion steps. Therefore, it was hypothesized that microtubular inhibition might be a novel approach for the treatment of HCV infection. Here, the inhibitory effects of our recently developed microtubule inhibitors were studied in the HCV replicon luciferase reporter system and the infectious system. In addition, the combination responses of microtubule inhibitors with daclatasvir, which is a clinically used HCV NS5A inhibitor, were also evaluated. Our results indicated that microtubule targeting had activity against HCV replication and showed synergistic effect with a current clinical drug.

Rethinking Remdesivir: Synthesis, Antiviral Activity, and Pharmacokinetics of Oral Lipid Prodrugs.

Remdesivir (RDV; GS-5734) is currently the only FDA-approved antiviral drug for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The drug is approved for use in adults or children 12 years or older who are hospitalized for the treatment of COVID-19 on the basis of an acceleration of clinical recovery for inpatients with this disease. Unfortunately, the drug must be administered intravenously, restricting its use to those requiring hospitalization for relatively advanced disease. RDV is also unstable in plasma and has a complex activation pathway which may contribute to its highly variable antiviral efficacy in SARS-CoV-2-infected cells. Potent orally bioavailable antiviral drugs for early treatment of SARS-CoV-2 infection are urgently needed, and several, including molnupiravir and PF-07321332, are currently in clinical development. We focused on making simple, orally bioavailable lipid analogs of remdesivir nucleoside (RVn; GS-441524) that are processed to RVn monophosphate, the precursor of the active RVn triphosphate, by a single-step intracellular cleavage. In addition to high oral bioavailability, stability in plasma, and simpler metabolic activation, new oral lipid prodrugs of RVn had submicromolar anti-SARS-CoV-2 activity in a variety of cell types, including Vero E6, Calu-3, Caco-2, human pluripotent stem cell (PSC)-derived lung cells, and Huh7.5 cells. In Syrian hamsters, oral treatment with 1-O-octadecyl-2-O-benzyl-glycero-3-phosphate RVn (ODBG-P-RVn) was well tolerated and achieved therapeutic levels in plasma above the 90% effective concentration (EC90) for SARS-CoV-2. The results suggest further evaluation as an early oral treatment for SARS-CoV-2 infection to minimize severe disease and reduce hospitalizations.

Rethinking Remdesivir: Synthesis, Antiviral Activity and Pharmacokinetics of Oral Lipid Prodrugs.

Remdesivir (RDV, GS-5734) is currently the only FDA-approved antiviral drug for the treatment of SARS CoV-2 infection. The drug is approved for use in adults or children 12-years or older who are hospitalized for the treatment of COVID-19 on the basis of an acceleration of clinical recovery for inpatients with this disease. Unfortunately, the drug must be administered intravenously, restricting its use to those requiring hospitalization for relatively advanced disease. RDV is also unstable in plasma and has a complex activation pathway which may contribute to its highly variable antiviral efficacy in SARS-CoV-2 infected cells. Potent orally bioavailable antiviral drugs for early treatment of SARS-CoV-2 infection are urgently needed and several including molnupiravir and PF-07321332 are currently in clinical development. We focused on making simple, orally bioavailable lipid analogs of Remdesivir nucleoside (RVn, GS-441524) that are processed to RVn-monophosphate, the precursor of the active RVn-triphosphate, by a single-step intracellular cleavage. In addition to high oral bioavailability, stability in plasma and simpler metabolic activation, new oral lipid prodrugs of RVn had submicromolar anti-SARS-CoV-2 activity in a variety of cell types including Vero E6, Calu-3, Caco-2, human pluripotent stem cell (PSC)-derived lung cells and Huh7.5 cells. In Syrian hamsters oral treatment with ODBG-P-RVn was well tolerated and achieved therapeutic levels in plasma above the EC90 for SARS-CoV-2. The results suggest further evaluation as an early oral treatment for SARS-CoV-2 infection to minimize severe disease and reduce hospitalizations.

Ni Hierarchical Structures Supported on Titania Nanowire Arrays as Efficient Nonenzymatic Glucose Sensor.

Developing new advanced nonenzymatic electrochemical nano-sensors for glucose detection has attracted intensive attraction. In this work, we designed a novel nanocomposite nonenzymatic glucose sensor by fabricating hierarchically nanostructured metal nickel on titania nanowire arrays, which was loaded on a transparent conductive substrate (i.e., fluorine-doped tin oxide, FTO) surface by mild hydrothermal method. Due to the large surface area of the hierarchically nanostructured Ni and fast electron transfer of the TiO2 nanowire arrays electrode, the nanocomposite electrode shows excellent electrochemical activity toward the oxidation of glucose. The electrode exhibits high sensitivity in detecting glucose concentration (1472 µA mM-1 cm-2) with a wide linear range from 2×10-4 M to 2×10-3 M, fast response time (within 5 s), and small detection limit (10 µM) (S/N = 3). The good analytical performance, low cost and simple preparation method make this novel electrode material promising for the development of effective glucose nonenzymatic glucose sensor.

Octadecyloxyethyl benzyl tenofovir: A novel tenofovir diester provides sustained intracellular levels of tenofovir diphosphate.

Pre-exposure prophylaxis (PrEP) with topically or systemically administered antiretroviral agents can prevent acquisition of human immunodeficiency virus type 1 (HIV-1) infection. However, in clinical trials using tenofovir-containing agents, HIV-1 acquisition is reduced but not eliminated. Incomplete adherence remains the major contributor to failure. Sustained release or long-acting antiretroviral agents may provide better HIV-1 protection by reducing the clinical impact of incomplete adherence. To reduce dosing frequency, we synthesized a novel tenofovir prodrug, octadecyloxyethyl benzyl tenofovir (ODE-Bn-TFV), that is designed to release TFV slowly in tissues, and showed potent anti-HIV activity in vitro (EC50 = 1.7 nM). In cells exposed to 14C labeled TFV, ODE-Bn-TFV or the quickly activated monoester ODE-TFV, rapid cellular uptake for both lipophilic analogs was noted, achieving 50-fold higher levels than unmodified TFV after 48 h. Following exposure to ODE-[8-14C]TFV, the intracellular diphosphate levels were approximately four-fold higher than with ODE-Bn-TFV. However, intracellular TFVpp drug levels fell rapidly yielding a half-life of about two days. TFVpp levels in ODE-Bn-TFV treated cells decreased much more slowly and reached half-maximal levels in about seven days. These results suggest early accumulation of ODE-Bn-TFV followed by sustained intracellular release following cleavage of the ester bonds linking the ODE and benzyl moieties to the active molecular precursor, thereby potentially allowing for less frequent administration than with more rapidly activated forms of tenofovir.

Discovery and Computational Analyses of Novel Small Molecule Zika Virus Inhibitors.

Zika virus (ZIKV), one of the flaviviruses, has attracted worldwide attention since its large epidemics around Brazil. Association of ZIKV infection with microcephaly and neurological problems such as Guillain-Barré syndrome has prompted intensive pathological investigations. However, there is still a long way to go on the discovery of effective anti-ZIKV therapeutics. In this study, an in silico screening of the National Cancer Institute (NCI) diversity set based on ZIKV NS3 helicase was performed using a molecular docking approach. Selected compounds with drug-like properties were subjected to cell-based antiviral assays resulting in the identification of two novel lead compounds (named Compounds 1 and 2). They inhibited ZIKV infection with IC50 values at the micro-molar level (8.5 µM and 15.2 µM, respectively). Binding mode analysis, absolute binding free energy calculation, and structure-activity relationship studies of these two compounds revealed their possible interactions with ZIKV NS3 helicase, suggesting a mechanistic basis for further optimization. These two novel small molecules may represent new leads for the development of inhibitory drugs against ZIKV.

Genetic diversity and structure of Elymus tangutorum accessions from western China as unraveled by AFLP markers.

BACKGROUND: Understanding genetic diversity of wild plant germplasm and the relationships between ecogeographic and genetic characteristics may provide insights for better utilizing and conserving genetic resources. Elymus tangutorum (Nevski) Hand.-Mazz, a cool-season hexaploid perennial, is an important pasture bunchgrass species used for forages and grassland restoration in Qinghai-Tibet Plateau and northwest China. In this study, 27 E. tangutorum accessions from diverse origins of western China were evaluated using AFLP markers in an effort to delve into the genetic relationships among them. The effects of eco-environmental factors and geographical isolation on the genetic diversity and population structure were also elucidated. RESULTS: On account of 554 polymorphic fragments amplified with 14 primer combinations, the mean values of some marker parameters including polymorphic information content, resolving power and marker index were 0.2504, 14.10 and 23.07, respectively, validating the high efficiency and reliability of the markers selected. Genetic dissimilarity index values among accessions ranged from 0.1024 to 0.7137 with a mean of 0.2773. STRUCTURE, UPGMA clustering and PCoA analyses showed that all accessions could be divided into the three main clusters; however, this results do not exactly coincide with geographic groups. We found medium differentiation (F ST = 0.162) between Qinghai-Tibet Plateau (QTP) and Xinjiang (XJC), and high differentiation (F ST = 0.188) among three Bayesian subgroups. A significant correlation (r = 0.312) between genetic and geographical distance was observed by Mantel test in the species level, while the weak correlation was detected between genetic and environmental distance for all accessions and most of geographical groups. In addition, a significant ecological influence of average annual precipitation on genetic distance was revealed in XJC group and the Bayesian subgroup A. CONCLUSION: This study indicates that AFLP technique are a useful tool to measure genetic diversity in E. tangutorum, showing that geographical and environmental factors (especially precipitation) together, play a crucial role in genetic differentiation patterns. These findings underline the importance of local adaptation in shaping patterns of genetic variability and population structure in E. tangutorum germplasm collected in Western China.

Virtual Screening, Biological Evaluation, and 3D-QSAR Studies of New HIV-1 Entry Inhibitors That Function via the CD4 Primary Receptor.

Human immunodeficiency virus type 1 (HIV-1) is responsible for the majority of HIV infections worldwide, and we still lack a cure for this infection. Blocking the interaction of HIV-1 and its primary receptor CD4 is one strategy for identifying new anti-HIV-1 entry inhibitors. Here we report the discovery of a novel ligand that can inhibit HIV-1 entry and infection via CD4. Biological and computational analyses of this inhibitor and its analogs, using bioactivity evaluation, Rule of Five (RO5), comparative molecular field analysis (CoMFA)/comparative molecular similarity index analysis (CoMSIA) models, and three-dimensional quantitative structure-activity relationship (3D-QSAR), singled out compound 3 as a promising lead molecule for the further development of therapeutics targeting HIV-1 entry. Our study demonstrates an effective approach for employing structure-based, rational drug design techniques to identify novel antiviral compounds with interesting biological activities.

Nasal commensal Staphylococcus epidermidis counteracts influenza virus.

Several microbes, including Staphylococcus epidermidis (S. epidermidis), a Gram-positive bacterium, live inside the human nasal cavity as commensals. The role of these nasal commensals in host innate immunity is largely unknown, although bacterial interference in the nasal microbiome may promote ecological competition between commensal bacteria and pathogenic species. We demonstrate here that S. epidermidis culture supernatants significantly suppressed the infectivity of various influenza viruses. Using high-performance liquid chromatography together with mass spectrometry, we identified a giant extracellular matrix-binding protein (Embp) as the major component involved in the anti-influenza effect of S. epidermidis. This anti-influenza activity was abrogated when Embp was mutated, confirming that Embp is essential for S. epidermidis activity against viral infection. We also showed that both S. epidermidis bacterial particles and Embp can directly bind to influenza virus. Furthermore, the injection of a recombinant Embp fragment containing a fibronectin-binding domain into embryonated eggs increased the survival rate of virus-infected chicken embryos. For an in vivo challenge study, prior Embp intranasal inoculation in chickens suppressed the viral titres and induced the expression of antiviral cytokines in the nasal tissues. These results suggest that S. epidermidis in the nasal cavity may serve as a defence mechanism against influenza virus infection.

[The newest developments of the study on anti-HIV drugs].

Besides 36 (28 single-tablets and 8 fixed-dose combinations) used antiretroviral drugs clinically, there are a number of investigational antiretroviral agents currently in phase 2-3 clinical trial. Tenofoviralafenamidefumarate (TAF) is a novel nucleoside analogue reverse transcriptase inhibitor that is potent and less toxicity than tenofovir (TDF). Doravirine is a non-nucleoside analogue reverse transcriptase inhibitor that demonstrates activity against NNRTI-resistant viral strains. GSK744 is an integrase inhibitor with a long acting preparation. In addition, several drugs with new mechanisms are also noted, for example, BMS-663 068 is a small molecule CD4 attachment inhibitors and cenicriviroc is a novel CCR5/CCR2 antagonist with antiretroviral activity and anti-inflammatory effects. Several drug classes that target known pathways in HIV latency have being developed, and leading the list are histone deacetylase inhibitors. Other agents include protein kinase C activators, positive transcription elongation factor activators, DNA methyl-transferase inhibitors and histone methyl-transferase inhibitors and so on. This review is focused on the above-mentioned drug candidates that may be used in clinical in next couple of years and those compounds that can reverse latent HIV infections.

Influenza A penetrates host mucus by cleaving sialic acids with neuraminidase.

BACKGROUND: Influenza A virus (IAV) neuraminidase (NA) cleaves sialic acids (Sias) from glycans. Inhibiting NA with oseltamivir suppresses both viral infection, and viral release from cultured human airway epithelial cells. The role of NA in viral exit is well established: it releases budding virions by cleaving Sias from glycoconjugates on infected cells and progeny virions. The role of NA in viral entry remains unclear. Host respiratory epithelia secrete a mucus layer rich in heavily sialylated glycoproteins; these could inhibit viral entry by mimicking sialylated receptors on the cell surface. It has been suggested that NA allows influenza to penetrate the mucus by cleaving these sialylated decoys, but the exact mechanism is not yet established. METHODS: We tested IAV interaction with secreted mucus using frozen human trachea/bronchus tissue sections, and bead-bound purified human salivary mucins (HSM) and purified porcine submaxillary mucins (PSM). The protective effect of mucus was analyzed using MDCK cells coated with purified HSM and PSM with known Sia content. Oseltamivir was used to inhibit NA activity, and the fluorescent reporter substrate, 4MU-Neu5Ac, was used to quantify NA activity. RESULTS: IAV binds to the secreted mucus layer of frozen human trachea/bronchus tissues in a Sia dependent manner. HSM inhibition of IAV infection is Sia dose-dependent, but PSM cannot inhibit infection of underlying cells. HSM competitively inhibits NA cleavage of 4MU-Neu5Ac, reporter substrate. Human IAV effectively cleaves Sias from HSM but not from PSM, and binds to HSM but not to PSM. CONCLUSION: IAV interacts with human mucus on frozen tissue sections and mucus-coated beads. Inhibition of IAV infection by sialylated human mucus is dose-dependent, and enhanced when NA is inhibited with oseltamivir. Thus NA cleaves sialylated decoys during initial stages of infection. Understanding IAV interactions with host mucins is a promising new avenue for drug development.

[The in-vitro effects of arbidol hydrochloride against 2009 new influenza virus A (H1N1)].

OBJECTIVE: To detect the in-vitro effects of arbidol hydrochloride against 2009 new influenza virus A (H1N1). METHODS: The activity of arbidol hydrochloride against 2009 new influenza virus A (H1N1) was determined in MDCK cell cultures. Hemagglutination assay, observation of cytopathic effects, RT-PCR and quantitative RT-PCR tests were performed for determination of virus titers. Inhibition concentration 50% and cytotoxic concentration 50% were calculated with Chou's Menu of Dose-Effect Program. RESULTS: Arbidol hydrochloride showed low cytotoxicity (cytotoxic concentration 50%>100 µmol/L)and significant anti-2009 new influenza virus A (H1N1) activity in cell cultures. Inhibition concentration 50% were (5.5 ± 0.9), (3.4 ± 0.8), and (1.5 ± 0.2) µmol/L in hemagglutination assay, cytopathic effect test, and quantitative RT-PCR assay, respectively. CONCLUSION: Arbidol has low cytotoxicity and high anti-virus activity and can effectively trigger the activities of interferon and immune response, and therefore can be a valuable anti-influenza virus drug.

Th1/Th2 cytokine profile in patients coinfected with HIV and Leishmania in Brazil.

To evaluate the effects of HIV on immune responses in cutaneous leishmaniasis (CL), we quantified cytokine levels from plasma and stimulated peripheral blood mononuclear cells (PBMCs) from individuals infected with HIV and/or CL. Gamma interferon (IFN-γ) and interleukin 13 (IL-13) levels and the ratio of IFN-γ to IL-10 produced in response to stimulation with soluble Leishmania antigens were significantly lower in HIV-Leishmania-coinfected patients than in CL-monoinfected patients.

Rapid multiplexed immunoassay for simultaneous serodiagnosis of HIV-1 and coinfections.

Diagnosis of opportunistic infections in HIV-infected individuals remains a major public health challenge, particularly in resource-limited settings. Here, we describe a rapid diagnostic system that delivers a panel of serologic immunoassay results using a single drop of blood, serum, or plasma. The system consists of disposable cartridges and a simple reader instrument, based on an innovative implementation of planar waveguide imaging technology. The cartridge incorporates a microarray of recombinant antigens and antibody controls in a fluidic channel, providing multiple parallel fluorescence immunoassay results for a single sample. This study demonstrates system performance by delivering antibody (Ab) reactivity results simultaneously for multiple antigens of HIV-1, Treponema pallidum (syphilis), and hepatitis C virus (HCV) in a collection of clinical serum, plasma, and whole-blood samples. By plotting antibody reactivity (fluorescence intensity) for known positive and negative samples, empirical reactivity cutoff values were defined. The HIV-1 assay shows 100% agreement with known seroreactivity for a collection of 82 HIV Ab-positive and 142 HIV Ab-negative samples, including multiple samples with HCV and syphilis coinfection. The treponema-specific syphilis assay correctly identifies 67 of 68 T. pallidum Ab-positive and 100 of 102 T. pallidum Ab-negative samples, and the HCV assay correctly identifies 59 of 60 HCV Ab-positive and 120 of 121 HCV Ab-negative samples. Multiplexed assay performance for whole-blood samples is also demonstrated. The ability to diagnose HIV and opportunistic infections simultaneously at the point of care should lead to more effective therapy decisions and improved linkage to care.

Extensive geographical mixing of 2009 human H1N1 influenza A virus in a single university community.

Despite growing interest in the molecular epidemiology of influenza virus, the pattern of viral spread within individual communities remains poorly understood. To determine the phylogeography of influenza virus in a single population, we examined the spatial diffusion of H1N1/09 influenza A virus within the student body of the University of California, San Diego (UCSD), sampling for a 1-month period between October and November 2009. Despite the highly focused nature of our study, an analysis of complete viral genome sequences revealed between 24 and 33 independent introductions of H1N1/09 into the UCSD community, comprising much of the global genetic diversity in this virus. These data were also characterized by a relatively low level of on-campus transmission as well as extensive spatial mixing, such that there was little geographical clustering by either student residence or city ZIP code. Most notably, students experiencing illness on the same day and residing in the same dorm possessed phylogenetically distinct lineages. H1N1/09 influenza A virus is therefore characterized by a remarkable spatial fluidity, which is likely to impede community-based methods for its control, including class cancellations, quarantine, and chemoprophylaxis.

[Anti-HIV-1 activity and structure-activity relationship of pyranocoumarin analogs].

The purpose of this study is to find out anti-HIV-1 reverse transcriptase (RT)/protease (PR) activity and inhibition of virus replication in cell cultures of novel coumarin analogs and determine their structure-activity relationship. Coumarin derivatives have been demonstrated to inhibit the activity of HIV-1 RT/PR in cell free system. It also shows inhibition effects to HIV-1 replication in cell culture. Based on the Chinese traditional pharmacological characteristics and protein three dimension computer aided design, analogs of tetracyclic dipyranocoumarin were synthesized from natural leading compounds. We studied the relationship of antiviral effects and chemical structures via HIV-1 PR/RT enzyme models and cell culture model system. Seven compounds were designed and tested. Several compounds showed anti-HIV-1 activity in varying degrees, especially V0201 showed much higher anti-HIV-1 activity with 3.56 and 0.78 micromol x L(-1) of IC50 against HIV-1 PR/RT and 0.036 micromol x L(-1) against HIV-1 replication in PBMC cultures. V0201 with a novel structure may be a new leading compound. These new compounds are valuable for development of new anti-HIV drugs in the future.

Pandemic (H1N1) 2009 Surveillance in Marginalized Populations, Tijuana, Mexico.

To detect early cases of pandemic (H1N1) 2009 infection, in 2009 we surveyed 303 persons from marginalized populations of drug users, sex workers, and homeless persons in Tijuana, Mexico. Six confirmed cases of pandemic (H1N1) 2009 were detected, and the use of rapid, mobile influenza testing was demonstrated.

Flow cytometric screening for anti-leishmanials in a human macrophage cell line.

High-throughput drug screening methods against the intracellular stage of Leishmania have been facilitated by the development of in vitro models of infection. The use of cell lines rather than primary cells facilitates these methods. Peripheral blood mononuclear cell (PBMC) derived macrophages and THP-1 cells were infected with stationary phase egfp transfected Leishmania amazonensis parasites and then treated with anti-leishmanial compounds. Drug activity was measured using a flow cytometric approach, and toxicity was assessed using either the MTT assay or trypan blue dye exclusion. Calculated EC(50)'s for amphotericin B, sodium stibogluconate, and miltefosine were 0.1445±0.0005µg/ml, 0.1203±0.018mg/ml, and 26.71µM using THP-1 cells, and 0.179±0.035µg/ml, 0.1948±0.0364mg/ml, and 13.77±10.74µM using PBMC derived macrophages, respectively. We conclude that a flow cytometric approach using egfp transfected Leishmania species can be used to evaluate anti-leishmanial compounds against the amastigote stage of the parasite in THP-1 cells with excellent concordance to human PBMC derived macrophages.