Generation of Glucocorticoid Resistant SARS-CoV-2 T-Cells for Adoptive Cell Therapy (preprint)

Adoptive cell therapy with viral-specific T cells has been successfully used to treat life-threatening viral infections, supporting the application of this approach against COVID-19. We expanded SARS-CoV-2 T-cells from the peripheral blood of COVID-19-recovered donors and non-exposed controls using different culture conditions. We observed that the choice of cytokines modulates the expansion, phenotype and hierarchy of antigenic recognition by SARS-CoV-2 T-cells. Culture with IL-2/4/7 but not other cytokine-driven conditions resulted in >1000 fold expansion in SARS-CoV-2 T-cells with a retained phenotype, function and hierarchy of antigenic recognition when compared to baseline (pre-expansion) samples. Expanded CTLs were directed against structural SARS-CoV-2 proteins, including the receptor-binding domain of Spike. SARS-CoV-2 T-cells could not be efficiently expanded from the peripheral blood of non-exposed controls. Since corticosteroids are used for the management of severe COVID-19, we developed an efficient strategy to inactivate the glucocorticoid receptor gene (NR3C1) in SARS-CoV-2 CTLs using CRISPR-Cas9 gene editing.Funding: Supported in part by the generous philanthropic contributions to The University of Texas MD Anderson Cancer Center AML Moonshot Program, by the grants from National Institute of Health, National Cancer Institute 5R01CA211044-04 and Cancer Center Support (CORE) Grant (CA016672) that support the Flow Cytometry and Cellular Imaging Facility and the RNA sequencing core facility at MD Anderson Cancer Center.Conflict of Interest: The authors declare no competing interests.Ethical Approval: Buffy coat units were processed from 500mL of whole blood collected from each of the 10 COVID-19 recovered donors (CoV-RD) and 20 mL of peripheral blood from 5 healthy donors were collected under local Institutional Review Board approved protocols (Lab02-0630 and PA13-0647) and following informed consent.

The Anti-histamine Azelastine, Identified by Computational Drug Repurposing, Inhibits SARS-CoV-2 Infection in Reconstituted Human Nasal Tissue In Vitro (preprint)

Background: The COVID-19 pandemic is an enormous threat for healthcare systems and economies worldwide that urgently demands effective preventive and therapeutic strategies. Unlike the development of vaccines and new drugs specifically targeting SARS-CoV-2, repurposing of approved or clinically tested drugs can provide an immediate solution. Methods: We applied a novel computational approach to search among approved and clinically tested drugs from the DrugBank database. Candidates were selected based on Shannon entropy homology and predefined activity profiles of three small molecules with proven anti-SARS-CoV activity and a published data set. Antiviral activity of a predicted drug, azelastine, was tested in vitro in SARS-CoV-2 infection assays with Vero E6 monkey kidney epithelial cells and reconstituted human nasal tissue. The effect on viral replication was assessed by quantification of viral genomes by droplet digital PCR. Findings: The computational approach with four independent queries identified major drug families, most often and in overlapping fashion anti-infective, anti-inflammatory, anti-hypertensive, anti-histamine and neuroactive drugs. Azelastine, an histamine 1 receptor-blocker, was predicted in multiple screens, and based on its attractive safety profile and availability in nasal formulation, was selected for experimental testing. Azelastine significantly reduced cytopathic effect and SARS-CoV-2 infection of Vero E6 cells with an EC50 of ~6 M both in a preventive and treatment setting. Furthermore, azelastine in a commercially available nasal spray tested at 5-fold dilution was highly potent in inhibiting viral propagation in SARS-CoV-2 infected reconstituted human nasal tissue. Interpretations: Azelastine, an anti-histamine, available in nasal sprays developed against allergic rhinitis may be considered as a topical prevention or treatment of nasal colonization with SARS-CoV-2. As such, it could be useful in reducing viral spread and prophylaxis of COVID-19. Ultimately, its potential benefit should be proven in clinical studies. Funding: provided by the Hungarian government to the National Laboratory of Virology and by CEBINA GmbH.

Levels of genetic diversity of SARS-CoV-2 virus: reducing speculations about the genetic variability of the virus in South America (preprint)

In this work, we evaluated the levels of genetic diversity in 38 complete Genomes of SARS-CoV-2 from six countries in South America, using specific methodologies for paired FST, AMOVA, mismatch, demographic and spatial expansions, molecular diversity and for the time of evolutionary divergence. The analyses showed non-significant evolutionary divergences within and between the six countries, as well as a significant similarity to the time of genetic evolutionary divergence between all populations. Thus, it seems safe to affirm that we will find similar results for the other Countries of South America, reducing speculation about the existence of rapid and silent mutations that, although there are as we have shown in this work, do not increase, until this moment, the genetic variability of the Virus, a fact that would hinder the work with molecular targets for vaccines and drugs in general.

SARS-CoV-2 ribosomal frameshifting pseudoknot: Improved secondary structure prediction and detection of inter-viral structural similarity (preprint)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to the COVID-19 pandemic; a pandemic of a scale that has not been seen in the modern era. Despite over 29 million reported cases and over 900,000 deaths worldwide as of September 2020, herd immunity and widespread vaccination efforts by many experts are expected to be insufficient in addressing this crisis for the foreseeable future. Thus, there is an urgent need for treatments that can lessen the effects of SARS-CoV-2 in patients who become seriously affected. Many viruses including HIV, the common cold, SARS-CoV and SARS-CoV-2 use a unique mechanism known as -1 programmed ribosomal frameshifting (-1 PRF) to successfully replicate and infect cells in the human host. SARS-CoV (the coronavirus responsible for SARS) and SARS-CoV-2 possess a unique RNA structure, a three-stemmed pseudoknot, that stimulates -1 PRF. Recent experiments identified that small molecules can be introduced as antiviral agents to bind with the pseudoknot and disrupt its stimulation of -1 PRF. If successfully developed, small molecule therapy that targets -1 PRF in SARS-CoV-2 is an excellent strategy to improve patients' prognoses. Crucial to developing these successful therapies is modeling the structure of the SARS-CoV-2 -1 PRF pseudoknot. Following a structural alignment approach, we identify similarities in the -1 PRF pseudoknots of the novel coronavirus SARS-CoV-2, the original SARS-CoV, as well as a third coronavirus: MERS-CoV, the coronavirus responsible for Middle East Respiratory Syndrome (MERS). In addition, we provide a better understanding of the SARS-CoV-2 -1 PRF pseudoknot by comprehensively investigating the structural landscape using a hierarchical folding approach. Since understanding the impact of mutations is vital to long-term success of treatments that are based on predicted RNA functional structures, we provide insight on SARS-CoV-2 -1 PRF pseudoknot sequence mutations and their effect on the resulting structure and its function.

LOX-1+ immature neutrophils predict severe COVID-19 patients at risk of thrombotic complications (preprint)

Rational: Lymphopenia and neutrophil/lymphocyte ratio may have prognostic value in coronavirus disease 2019 (COVID-19) severity. Objective: We sought to investigate the representation of neutrophil subsets in severe and critical COVID-19 patients based on Intensive Care Units (ICU) and non-ICU admission. Methods: We developed a multi-parametric neutrophil profiling strategy based on known neutrophil markers to distinguish COVID-19 phenotypes in critical and severe patients. Results: Our results showed that 80 percent of ICU patients develop strong myelemia with CD10-CD64+ immature neutrophils. Cellular profiling revealed two distinct neutrophil subsets expressing either the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) or the Interleukin-3 receptor alpha (CD123), both significantly overrepresented in ICU patients compared to non-ICU patients. The proportion of LOX-1-expressing immature neutrophils positively correlated with clinical severity, with the cytokine storm (IL-1{beta}, IL-6, IL-8, TNF), and with intravascular coagulation. Importantly, high proportions of LOX-1+-immature neutrophils are associated with high risks of severe thrombosis. Conclusions: Together these data suggest that point of care enumeration of LOX-1-immature neutrophils might help distinguish patients at risk of thrombosis complication and most likely to benefit from intensified anticoagulant therapy.

Rational design of a new class of protease inhibitors for the potential treatment of coronavirus diseases (preprint)

The main protease, Mpro, of SARSCoV2 is a key protein in the coronavirus life cycle and a major drug target. Based on crystal structures of SARSCoV2 Mpro complexed with peptidomimetic inhibitors, we recognized a structural motif shared with approved inhibitors of hepatitis C virus protease. Initial tests showed that several HCV protease inhibitors could indeed also inhibit Mpro. Based on the identified molecular scaffolds we designed a new generation of ketoamide-based Mpro inhibitors with a preorganized backbone conformation. One of the designed inhibitors, ML1000, shows particularly high affinity towards Mpro and inhibits SARSCoV2 viral replication in human cells at sub-micromolar concentrations. Our findings identify ML1000 as a promising new scaffold for the development of anti-coronavirus drugs.

Emergence and expansion of highly infectious spike:D614G mutant SARS-CoV-2 in central India (preprint)

COVID 19 has emerged as global pandemic with largest damage to the economy and human psyche. The genomic signature deciphered during the ongoing pandemic period is valuable to understand the virus evolutionary patterns and spread across the globe. Increased availability of genome information of circulating strain in our country will enable to generate selective details in virulent and non virulent markers to prophylaxis and therapeutic interventions. The first case of SARS CoV-2 was detected in Chambal region of Madhya Pradesh state in mid of March 2020 followed by multiple introduction events and expansion of COVID-19 cases within 3 months in this region. We analyzed around 5000 COVID-19 suspected samples referred to Defence Research and Development Establishment, Gwalior, Madhya Pradesh. A total of 136 cases were found positive over a span of three months period this includes virus introduction to region and further spread. Whole genome sequences employing Oxford nanopore technology were deciphered for 26 SARS-CoV-2 circulating in 10 different districts in Madhya Pradesh State of India. The region witnessed index cases with multiple travel history responsible for introduction of COVID-19 followed by remarkable expansion of virus. The genome wide substitutions including in important viral proteins were observed. The detailed phylogenetic analysis revealed the circulating SARS-CoV-2 clustered in multiple clades A2a, A4 and B. The cluster wise segregation was observed suggesting multiple introduction links and evolution of virus in the region. This is the first comprehensive details of whole genome sequence analysis from central India region, which will add genome wide knowledge towards diagnostic and therapeutic interventions.

Generation of glucocorticoid resistant SARS-CoV-2 T-cells for adoptive cell therapy (preprint)

Adoptive cell therapy with viral-specific T cells has been successfully used to treat life-threatening viral infections, supporting the application of this approach against COVID-19. We expanded SARS-CoV-2 T-cells from the peripheral blood of COVID-19-recovered donors and non-exposed controls using different culture conditions. We observed that the choice of cytokines modulates the expansion, phenotype and hierarchy of antigenic recognition by SARS-CoV-2 T-cells. Culture with IL-2/4/7 but not other cytokine-driven conditions resulted in >1000 fold expansion in SARS-CoV-2 T-cells with a retained phenotype, function and hierarchy of antigenic recognition when compared to baseline (pre-expansion) samples. Expanded CTLs were directed against structural SARS-CoV-2 proteins, including the receptor-binding domain of Spike. SARS-CoV-2 T-cells could not be efficiently expanded from the peripheral blood of non-exposed controls. Since corticosteroids are used for the management of severe COVID-19, we developed an efficient strategy to inactivate the glucocorticoid receptor gene (NR3C1) in SARS-CoV-2 CTLs using CRISPR-Cas9 gene editing.

Antibody potency, effector function and combinations in protection from SARS-CoV-2 infection in vivo (preprint)

SARS-CoV-2, the causative agent of COVID-19, is responsible for over 24 million infections and 800,000 deaths since its emergence in December 2019. There are few therapeutic options and no approved vaccines. Here we examine the properties of highly potent human monoclonal antibodies (hu-mAbs) in a mouse adapted model of SARS-CoV-2 infection (SARS-CoV-2 MA). In vitro antibody neutralization potency did not uniformly correlate with in vivo activity, and some hu-mAbs were more potent in combination in vivo. Analysis of antibody Fc regions revealed that binding to activating Fc receptors is essential for optimal protection against SARS-CoV-2 MA. The data indicate that hu-mAb protective activity is dependent on intact effector function and that in vivo testing is required to establish optimal hu-mAb combinations for COVID-19 prevention.