Publications by authors named "Rita P Loudermilk"

7 Publications

  • Page 1 of 1

Global absence and targeting of protective immune states in severe COVID-19.

Nature 2021 03 25;591(7848):124-130. Epub 2021 Jan 25.

Department of Pathology, University of California San Francisco, San Francisco, CA, USA.

Although infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has pleiotropic and systemic effects in some individuals, many others experience milder symptoms. Here, to gain a more comprehensive understanding of the distinction between severe and mild phenotypes in the pathology of coronavirus disease 2019 (COVID-19) and its origins, we performed a whole-blood-preserving single-cell analysis protocol to integrate contributions from all major immune cell types of the blood-including neutrophils, monocytes, platelets, lymphocytes and the contents of the serum. Patients with mild COVID-19 exhibit a coordinated pattern of expression of interferon-stimulated genes (ISGs) across every cell population, whereas these ISG-expressing cells are systemically absent in patients with severe disease. Paradoxically, individuals with severe COVID-19 produce very high titres of anti-SARS-CoV-2 antibodies and have a lower viral load compared to individuals with mild disease. Examination of the serum from patients with severe COVID-19 shows that these patients uniquely produce antibodies that functionally block the production of the ISG-expressing cells associated with mild disease, by activating conserved signalling circuits that dampen cellular responses to interferons. Overzealous antibody responses pit the immune system against itself in many patients with COVID-19, and perhaps also in individuals with other viral infections. Our findings reveal potential targets for immunotherapies in patients with severe COVID-19 to re-engage viral defence.
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http://dx.doi.org/10.1038/s41586-021-03234-7DOI Listing
March 2021

Global Absence and Targeting of Protective Immune States in Severe COVID-19.

bioRxiv 2020 Oct 29. Epub 2020 Oct 29.

While SARS-CoV-2 infection has pleiotropic and systemic effects in some patients, many others experience milder symptoms. We sought a holistic understanding of the severe/mild distinction in COVID-19 pathology, and its origins. We performed a whole-blood preserving single-cell analysis protocol to integrate contributions from all major cell types including neutrophils, monocytes, platelets, lymphocytes and the contents of serum. Patients with mild COVID-19 disease display a coordinated pattern of interferon-stimulated gene (ISG) expression across every cell population and these cells are systemically absent in patients with severe disease. Severe COVID-19 patients also paradoxically produce very high anti-SARS-CoV-2 antibody titers and have lower viral load as compared to mild disease. Examination of the serum from severe patients demonstrates that they uniquely produce antibodies with multiple patterns of specificity against interferon-stimulated cells and that those antibodies functionally block the production of the mild disease-associated ISG-expressing cells. Overzealous and auto-directed antibody responses pit the immune system against itself in many COVID-19 patients and this defines targets for immunotherapies to allow immune systems to provide viral defense.

One Sentence Summary: In severe COVID-19 patients, the immune system fails to generate cells that define mild disease; antibodies in their serum actively prevents the successful production of those cells.
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http://dx.doi.org/10.1101/2020.10.28.359935DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7605559PMC
October 2020

Global Absence and Targeting of Protective Immune States in Severe COVID-19.

Res Sq 2020 Oct 28. Epub 2020 Oct 28.

Department of Pathology, San Francisco, 513 Parnassus Ave, HSW512, San Francisco, CA 94143-0511, USA.

While SARS-CoV-2 infection has pleiotropic and systemic effects in some patients, many others experience milder symptoms. We sought a holistic understanding of the severe/mild distinction in COVID-19 pathology, and its origins. We performed a wholeblood preserving single-cell analysis protocol to integrate contributions from all major cell types including neutrophils, monocytes, platelets, lymphocytes and the contents of serum. Patients with mild COVID-19 disease display a coordinated pattern of interferonstimulated gene (ISG) expression across every cell population and these cells are systemically absent in patients with severe disease. Severe COVID-19 patients also paradoxically produce very high anti-SARS-CoV-2 antibody titers and have lower viral load as compared to mild disease. Examination of the serum from severe patients demonstrates that they uniquely produce antibodies with multiple patterns of specificity against interferon-stimulated cells and that those antibodies functionally block the production of the mild disease-associated ISG-expressing cells. Overzealous and autodirected antibody responses pit the immune system against itself in many COVID-19 patients and this defines targets for immunotherapies to allow immune systems to provide viral defense.
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http://dx.doi.org/10.21203/rs.3.rs-97042/v1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7605560PMC
October 2020

ReScan, a Multiplex Diagnostic Pipeline, Pans Human Sera for SARS-CoV-2 Antigens.

Cell Rep Med 2020 Oct 24;1(7):100123. Epub 2020 Sep 24.

Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.

Comprehensive understanding of the serological response to SARS-CoV-2 infection is important for both pathophysiologic insight and diagnostic development. Here, we generate a pan-human coronavirus programmable phage display assay to perform proteome-wide profiling of coronavirus antigens enriched by 98 COVID-19 patient sera. Next, we use ReScan, a method to efficiently sequester phage expressing the most immunogenic peptides and print them onto paper-based microarrays using acoustic liquid handling, which isolates and identifies nine candidate antigens, eight of which are derived from the two proteins used for SARS-CoV-2 serologic assays: spike and nucleocapsid proteins. After deployment in a high-throughput assay amenable to clinical lab settings, these antigens show improved specificity over a whole protein panel. This proof-of-concept study demonstrates that ReScan will have broad applicability for other emerging infectious diseases or autoimmune diseases that lack a valid biomarker, enabling a seamless pipeline from antigen discovery to diagnostic using one recombinant protein source.
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http://dx.doi.org/10.1016/j.xcrm.2020.100123DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7513813PMC
October 2020

Competitive SARS-CoV-2 Serology Reveals Most Antibodies Targeting the Spike Receptor-Binding Domain Compete for ACE2 Binding.

mSphere 2020 09 16;5(5). Epub 2020 Sep 16.

Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, USA

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread around the world, there is an urgent need for new assay formats to characterize the humoral response to infection. Here, we present an efficient, competitive serological assay that can simultaneously determine an individual's seroreactivity against the SARS-CoV-2 Spike protein and determine the proportion of anti-Spike antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. In this approach based on the use of enzyme-linked immunosorbent assays (ELISA), we present natively folded viral Spike protein receptor-binding domain (RBD)-containing antigens via avidin-biotin interactions. Sera are then competed with soluble ACE2-Fc, or with a higher-affinity variant thereof, to determine the proportion of ACE2 blocking anti-RBD antibodies. Assessment of sera from 144 SARS-CoV-2 patients ultimately revealed that a remarkably consistent and high proportion of antibodies in the anti-RBD pool targeted the epitope responsible for ACE2 engagement (83% ± 11%; 50% to 107% signal inhibition in our largest cohort), further underscoring the importance of tailoring vaccines to promote the development of such antibodies. With the emergence and continued spread of the SARS-CoV-2 virus, and of the associated disease, coronavirus disease 2019 (COVID-19), there is an urgent need for improved understanding of how the body mounts an immune response to the virus. Here, we developed a competitive SARS-CoV-2 serological assay that can simultaneously determine whether an individual has developed antibodies against the SARS-CoV-2 Spike protein receptor-binding domain (RBD) and measure the proportion of these antibodies that block interaction with the human angiotensin-converting enzyme 2 (ACE2) required for viral entry. Using this assay and 144 SARS-CoV-2 patient serum samples, we found that a majority of anti-RBD antibodies compete for ACE2 binding. These results not only highlight the need to design vaccines to generate such blocking antibodies but also demonstrate the utility of this assay to rapidly screen patient sera for potentially neutralizing antibodies.
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http://dx.doi.org/10.1128/mSphere.00802-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7494835PMC
September 2020

Immunologically distinct responses occur in the CNS of COVID-19 patients.

bioRxiv 2020 Sep 12. Epub 2020 Sep 12.

A subset of patients with COVID-19 display neurologic symptoms but it remains unknown whether SARS-CoV-2 damages the central nervous system (CNS) directly through neuroinvasion, or if neurological symptoms are due to secondary mechanisms, including immune-mediated effects. Here, we examined the immune milieu in the CNS through the analysis of cerebrospinal fluid (CSF) and in circulation through analysis of peripheral blood mononuclear cells (PBMCs) of COVID-19 patients with neurological symptoms. Single cell sequencing with paired repertoire sequencing of PBMCs and CSF cells show evidence for unique immune response to SARS-CoV-2 in the CNS. Strikingly, anti-SARS-CoV-2 antibodies are present in the CSF of all patients studied, but the antibody epitope specificity in the CSF and relative prevalence of B cell receptor sequences markedly differed when compared to those found in paired serum. Finally, using a mouse model of SARS-CoV-2 infection, we demonstrate that localized CNS immune responses occur following viral neuroinvasion, and that the CSF is a faithful surrogate for responses occurring uniquely in the CNS. These results illuminate CNS compartment-specific immune responses to SARS-CoV-2, forming the basis for informed treatment of neurological symptoms associated with COVID-19.
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http://dx.doi.org/10.1101/2020.09.11.293464DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7491516PMC
September 2020

Evaluation of SARS-CoV-2 serology assays reveals a range of test performance.

Nat Biotechnol 2020 10 27;38(10):1174-1183. Epub 2020 Aug 27.

J. David Gladstone Institutes, San Francisco, CA, USA.

Appropriate use and interpretation of serological tests for assessments of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure, infection and potential immunity require accurate data on assay performance. We conducted a head-to-head evaluation of ten point-of-care-style lateral flow assays (LFAs) and two laboratory-based enzyme-linked immunosorbent assays to detect anti-SARS-CoV-2 IgM and IgG antibodies in 5-d time intervals from symptom onset and studied the specificity of each assay in pre-coronavirus disease 2019 specimens. The percent of seropositive individuals increased with time, peaking in the latest time interval tested (>20 d after symptom onset). Test specificity ranged from 84.3% to 100.0% and was predominantly affected by variability in IgM results. LFA specificity could be increased by considering weak bands as negative, but this decreased detection of antibodies (sensitivity) in a subset of SARS-CoV-2 real-time PCR-positive cases. Our results underline the importance of seropositivity threshold determination and reader training for reliable LFA deployment. Although there was no standout serological assay, four tests achieved more than 80% positivity at later time points tested and more than 95% specificity.
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http://dx.doi.org/10.1038/s41587-020-0659-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7740072PMC
October 2020