Publications by authors named "Colin R Zamecnik"

9 Publications

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Multi-Immune Agonist Nanoparticle Therapy Stimulates Type I Interferons to Activate Antigen-Presenting Cells and Induce Antigen-Specific Antitumor Immunity.

Mol Pharm 2021 Mar 4;18(3):1014-1025. Epub 2021 Feb 4.

Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California 94158, United States.

Cancer immunity is mediated by a delicate orchestration between the innate and adaptive immune system both systemically and within the tumor microenvironment. Although several adaptive immunity molecular targets have been proven clinically efficacious, stand-alone innate immunity targeting agents have not been successful in the clinic. Here, we report a nanoparticle optimized for systemic administration that combines immune agonists for TLR9, STING, and RIG-I with a melanoma-specific peptide to induce antitumor immunity. These immune agonistic nanoparticles (iaNPs) significantly enhance the activation of antigen-presenting cells to orchestrate the development and response of melanoma-sensitized T-cells. iaNP treatment not only suppressed tumor growth in an orthotopic solid tumor model, but also significantly reduced tumor burden in a metastatic animal model. This combination biomaterial-based approach to coordinate innate and adaptive anticancer immunity provides further insights into the benefits of stimulating multiple activation pathways to promote tumor regression, while also offering an important platform to effectively and safely deliver combination immunotherapies for cancer.
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http://dx.doi.org/10.1021/acs.molpharmaceut.0c00984DOI Listing
March 2021

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

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

An Injectable Cytokine Trap for Local Treatment of Autoimmune Disease.

Biomaterials 2020 02 12;230:119626. Epub 2019 Nov 12.

Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, 94158, USA. Electronic address:

Systemic cytokine therapy is limited by toxicity due to activation of unwanted immune cells in off-target tissues. Injectable nanomaterials that interact with the immune system have potential to offer improved pharmacokinetics and cell specificity compared to systemic cytokine therapy by instead capturing and potentiating endogenous cytokine. Here we demonstrate the use of high aspect ratio polycaprolactone nanowires conjugated to cytokine-binding antibodies that assemble into porous matrices when injected into the subcutaneous space. Nanowires are well tolerated in vivo over several weeks, incite minimal foreign body response and resist clearance. Nanowires conjugated with JES6-1, an anti-interleukin-2 (IL-2) antibody, were designed to capture endogenous IL-2 and selectively activate tissue resident regulatory T cells (Tregs). Together these nanowire-antibody matrices were capable of sequestering endogenous IL-2 in the skin and were successful in rebalancing local immune compartments to a more suppressive, Treg-mediated phenotype in both wild type and transgenic murine autoimmune disease models.
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http://dx.doi.org/10.1016/j.biomaterials.2019.119626DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6930339PMC
February 2020

Bright Surface-Enhanced Raman Scattering with Fluorescence Quenching from Silica Encapsulated J-Aggregate Coated Gold Nanoparticles.

Adv Mater 2018 Feb 20;30(5). Epub 2017 Dec 20.

Department of Chemistry, University of Toronto, Toronto, Ontario, M5S3H6, Canada.

Plexitonic nanoparticles offer variable optical properties through tunable excitations, in addition to electric field enhancements that far exceed molecular resonators. This study demonstrates a way to design an ultrabright surface-enhanced Raman spectroscopy (SERS) signal while simultaneously quenching the fluorescence background through silica encapsulation of the semiconductor-metal composite nanoparticles. Using a multistep approach, a J-aggregate-forming organic dye is assembled on the surface of gold nanoparticles using a cationic linker. Excitonic resonance of the J-aggregate-metal system shows an enhanced SERS signal at an appropriate excitation wavelength. Further encapsulation of the decorated particles in silica shows a significant reduction in the fluorescence signal of the Raman spectra (5× reduction) and an increase in Raman scattering (7× enhancement) when compared to phospholipid encapsulation. This reduction in fluorescence is important for maximizing the useful SERS enhancement from the particle, which shows a signal increase on the order of 10 times greater than J-aggregated dye in solution and 24 times greater than Oxonica S421 SERS tag. The silica layer also serves to promote colloidal stability. The combination of reduced fluorescence background, enhanced SERS intensity, and temporal stability makes these particles highly distinguishable with potential to enable high-throughput applications such as SERS flow cytometry.
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http://dx.doi.org/10.1002/adma.201705381DOI Listing
February 2018

Injectable Polymeric Cytokine-Binding Nanowires Are Effective Tissue-Specific Immunomodulators.

ACS Nano 2017 11 15;11(11):11433-11440. Epub 2017 Nov 15.

Department of Bioengineering and Therapeutic Sciences, University of California , San Francisco, California 94158, United States.

Injectable nanomaterials that interact with the host immune system without surgical intervention present spatially anchored complements to cell transplantation and could offer improved pharmacokinetics compared to systemic cytokine therapy. Here we demonstrate fabrication of high aspect ratio polycaprolactone nanowires coupled with cytokine-binding antibodies that assemble into porous matrices when injected into the subcutaneous space. These structures are fabricated using a nanotemplating technique that allows for tunability of particle dimensions and utilize a straightforward maleimide conjugation chemistry to allow site-specific coupling to proteins. Nanowires are well tolerated in vivo and incite minimal inflammatory infiltrate. Nanowires conjugated with antibodies were designed to capture and potentiate endogenous interleukin-2 (IL-2), an important leukocyte activating cytokine. Together these nanowire-antibody matrices were capable of localizing endogenous IL-2 in the skin and activated targeted specific natural killer and T cell subsets, demonstrating both tissue- and cell-specific immune activation. These self-assembling nanowire matrices show promise as scaffolds to present engineered, local receptor-ligand interactions for cytokine-mediated disease.
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http://dx.doi.org/10.1021/acsnano.7b06094DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5709211PMC
November 2017