Publications by authors named "David B Lewis"

79 Publications

COVID-19 and cardiovascular disease: from basic mechanisms to clinical perspectives.

Nat Rev Cardiol 2020 09 20;17(9):543-558. Epub 2020 Jul 20.

Stanford Cardiovascular Institute, Stanford, CA, USA.

Coronavirus disease 2019 (COVID-19), caused by a strain of coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic that has affected the lives of billions of individuals. Extensive studies have revealed that SARS-CoV-2 shares many biological features with SARS-CoV, the zoonotic virus that caused the 2002 outbreak of severe acute respiratory syndrome, including the system of cell entry, which is triggered by binding of the viral spike protein to angiotensin-converting enzyme 2. Clinical studies have also reported an association between COVID-19 and cardiovascular disease. Pre-existing cardiovascular disease seems to be linked with worse outcomes and increased risk of death in patients with COVID-19, whereas COVID-19 itself can also induce myocardial injury, arrhythmia, acute coronary syndrome and venous thromboembolism. Potential drug-disease interactions affecting patients with COVID-19 and comorbid cardiovascular diseases are also becoming a serious concern. In this Review, we summarize the current understanding of COVID-19 from basic mechanisms to clinical perspectives, focusing on the interaction between COVID-19 and the cardiovascular system. By combining our knowledge of the biological features of the virus with clinical findings, we can improve our understanding of the potential mechanisms underlying COVID-19, paving the way towards the development of preventative and therapeutic solutions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41569-020-0413-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7370876PMC
September 2020

Development of CRISPR as an Antiviral Strategy to Combat SARS-CoV-2 and Influenza.

Cell 2020 05 29;181(4):865-876.e12. Epub 2020 Apr 29.

Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; ChEM-H, Stanford University, Stanford, CA 94305, USA. Electronic address:

The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, has highlighted the need for antiviral approaches that can target emerging viruses with no effective vaccines or pharmaceuticals. Here, we demonstrate a CRISPR-Cas13-based strategy, PAC-MAN (prophylactic antiviral CRISPR in human cells), for viral inhibition that can effectively degrade RNA from SARS-CoV-2 sequences and live influenza A virus (IAV) in human lung epithelial cells. We designed and screened CRISPR RNAs (crRNAs) targeting conserved viral regions and identified functional crRNAs targeting SARS-CoV-2. This approach effectively reduced H1N1 IAV load in respiratory epithelial cells. Our bioinformatic analysis showed that a group of only six crRNAs can target more than 90% of all coronaviruses. With the development of a safe and effective system for respiratory tract delivery, PAC-MAN has the potential to become an important pan-coronavirus inhibition strategy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cell.2020.04.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7189862PMC
May 2020

Disseminated Pneumocystis jirovecii Infection with Osteomyelitis in a Patient with CTLA-4 Haploinsufficiency.

J Clin Immunol 2020 02 18;40(2):412-414. Epub 2020 Jan 18.

Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, Stanford School of Medicine, 269 Campus Drive, CCSR Suite 3215, Stanford, CA, 94305-5366, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10875-020-00748-zDOI Listing
February 2020

Durable multitransgene expression in vivo using systemic, nonviral DNA delivery.

Sci Adv 2019 11 27;5(11):eaax0217. Epub 2019 Nov 27.

DNARx LLC, San Francisco, CA, USA.

Recombinant adeno-associated virus (AAV) vectors are transforming therapies for rare human monogenic deficiency diseases. However, adaptive immune responses to AAV and its limited DNA insert capacity, restrict their therapeutic potential. HEDGES (high-level extended duration gene expression system), a nonviral DNA- and liposome-based gene delivery platform, overcomes these limitations in immunocompetent mice. Specifically, one systemic HEDGES injection durably produces therapeutic levels of transgene-encoded human proteins, including FDA-approved cytokines and monoclonal antibodies, without detectable integration into genomic DNA. HEDGES also controls protein production duration from <3 weeks to >1.5 years, does not induce anti-vector immune responses, is reexpressed for prolonged periods following reinjection, and produces only transient minimal toxicity. HEDGES can produce extended therapeutic levels of multiple transgene-encoded therapeutic human proteins from DNA inserts >1.5-fold larger than AAV-based therapeutics, thus creating combinatorial interventions to effectively treat common polygenic diseases driven by multigenic abnormalities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciadv.aax0217DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6881169PMC
November 2019

Paraneoplastic and Therapy-Related Immune Complications in Thymic Malignancies.

Curr Treat Options Oncol 2019 06 22;20(7):62. Epub 2019 Jun 22.

Division of Immunology and Rheumatology, Department of Medicine, School of Medicine, Stanford University, Stanford, CA, 94305, USA.

Opinion Statement: The thymus is a key organ involved in establishing central immune tolerance. Thymic epithelial tumors (TETs) include thymomas and thymic carcinomas. Thymomas, which are histologically distinct from thymic carcinomas, lead to dysregulated thymopoiesis via decreased thymic epithelial expression of AIRE and MHC Class II, as well as via alterations in thymic architecture, thereby resulting in autoimmune complications that manifest as paraneoplastic disorders (PNDs). Although progress has been made in elucidating the mechanisms underlying thymoma-associated PNDs, there remains a great need to further define the underlying mechanisms and to identify additional immune biomarkers, such as novel antibodies (in "seronegative" cases) to facilitate diagnosis and monitoring of patients. In addition, a better understanding of the pathogenesis of PNDs could lead to improved treatment strategies for both thymomas and their immune complications. In advanced, refractory cases of TETs (both thymoma and thymic carcinoma), additional therapeutic approaches are needed. Immune checkpoint inhibitors have revolutionized the treatment of several malignancies and hold promise in the treatment of TETs; however, the risks for immune-related adverse events (especially for inducing PNDs as well as in the setting of pre-existing PNDs) underscore the need to optimize patient selection and improve clinical management before there can be widespread acceptance of checkpoint inhibitor therapy in patients with TETs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11864-019-0661-2DOI Listing
June 2019

Multiomics modeling of the immunome, transcriptome, microbiome, proteome and metabolome adaptations during human pregnancy.

Bioinformatics 2019 01;35(1):95-103

Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, USA.

Motivation: Multiple biological clocks govern a healthy pregnancy. These biological mechanisms produce immunologic, metabolomic, proteomic, genomic and microbiomic adaptations during the course of pregnancy. Modeling the chronology of these adaptations during full-term pregnancy provides the frameworks for future studies examining deviations implicated in pregnancy-related pathologies including preterm birth and preeclampsia.

Results: We performed a multiomics analysis of 51 samples from 17 pregnant women, delivering at term. The datasets included measurements from the immunome, transcriptome, microbiome, proteome and metabolome of samples obtained simultaneously from the same patients. Multivariate predictive modeling using the Elastic Net (EN) algorithm was used to measure the ability of each dataset to predict gestational age. Using stacked generalization, these datasets were combined into a single model. This model not only significantly increased predictive power by combining all datasets, but also revealed novel interactions between different biological modalities. Future work includes expansion of the cohort to preterm-enriched populations and in vivo analysis of immune-modulating interventions based on the mechanisms identified.

Availability And Implementation: Datasets and scripts for reproduction of results are available through: https://nalab.stanford.edu/multiomics-pregnancy/.

Supplementary Information: Supplementary data are available at Bioinformatics online.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/bioinformatics/bty537DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6298056PMC
January 2019

Allergic Diseases and Immune-Mediated Food Disorders in Pediatric Acute-Onset Neuropsychiatric Syndrome.

Pediatr Allergy Immunol Pulmonol 2018 Sep 17;31(3):158-165. Epub 2018 Sep 17.

Division of Immunology, Allergy and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Stanford, California.

The prevalence and impact of allergic and immune-mediated food disorders in pediatric acute-onset neuropsychiatric syndrome (PANS) are mostly unknown. We sought to explore the prevalence of atopic dermatitis (AD), asthma, allergic rhinitis (AR), IgE-mediated food allergies (FAs), and other immune-mediated food disorders requiring food avoidance in patients with PANS. In addition, to further understand the extent of food restriction in this population, we investigated the empiric use of dietary measures to improve PANS symptoms. Pediatric patients in a PANS Clinic and Research Program were given surveys regarding their caregiver burdens, allergic and food-related medical history, and whether food elimination resulted in perception of improvement of PANS symptoms. A review of health records was conducted to confirm that all responses in the survey were concordant with documentation of each patient's medical chart. Sixty-nine (ages 4-20 years) of 80 subjects who fulfilled PANS criteria completed the surveys. Thirteen (18.8%) had AD, 11 (15.9%) asthma, 33 (47.8%) AR, 11 (15.9%) FA, 1 (1.4%) eosinophilic gastrointestinal disorders, 1 (1.4%) food protein-induced enterocolitis syndrome, 3 (4.3%) milk protein-induced proctocolitis syndrome, and 3 (4.3%) celiac disease. Thirty subjects (43.5%) avoided foods due to PANS; elimination of gluten and dairy was most common and was associated with perceived improvement of PANS symptoms (by parents). This perceived improvement was not confirmed with objective data. The prevalence of allergic and immune-mediated food disorders in PANS is similar to the general population as reported in the literature, with the exception of AR that appears to be more prevalent in our PANS cohort. More research will be required to establish whether diet or allergies influence PANS symptoms.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/ped.2018.0888DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6154445PMC
September 2018

The ratio of circulating regulatory cluster of differentiation 4 T cells to endothelial progenitor cells predicts clinically significant acute rejection after heart transplantation.

J Heart Lung Transplant 2018 04 22;37(4):496-502. Epub 2017 Oct 22.

Division of Cardiovascular Medicine, Stanford University Medical Center, Stanford, California. Electronic address:

Background: The aim of this study was to determine the value of the ratio of the percentage of circulating regulatory cluster of differentiation 4 T cells (%Tregs) to the percentage of endothelial progenitor cells (%EPCs; Treg/EPC ratio) for predicting clinically significant acute rejection.

Methods: Peripheral blood %Tregs and %EPCs were quantified in 91 cardiac transplant recipients using flow cytometry at a mean of 42 ± 13 days after transplant. The primary end point was clinically significant acute rejection, defined as an event that led to an acute augmentation of immunosuppression in conjunction with an International Society for Heart and Lung Transplantation grade ≥ 2R in a right ventricular endomyocardial biopsy specimen or non-cellular rejection (specimen-negative rejection) with hemodynamic compromise (decrease in left ventricular ejection fraction by > 25%).

Results: Significant rejection occurred in 27 recipients (29.7%) during a median of 49.4 months (interquartile range, 37.0-62.0 months). The mean %Tregs and %EPCs were not significantly different between those with and without an episode of significant rejection, but the mean Treg/EPC ratio was significantly lower in recipients with significant rejection (44.9 vs 106.7, p = 0.001). Receiver operating characteristic curve analysis showed an area under the curve value for significant rejection for a Treg/EPC ratio of 0.712. The best cutoff value of the Treg/EPC ratio that distinguished between those with or without significant rejection was ≤ 18 by receiver operating characteristic curve analysis. Kaplan-Meier analysis revealed that patients with a Treg/EPC ratio of ≤ 18 had a significantly higher rate of rejection than those with a Treg/EPC ratio > 18 (61.5% vs 16.9%, log-rank p < 0.0001). A low Treg/EPC ratio was an independent predictor of significant rejection.

Conclusions: A low Treg/EPC ratio measured soon after heart transplantation is an independent predictor of acute rejection. The Treg/EPC ratio has potential as an early biomarker after heart transplantation for predicting acute rejection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.healun.2017.10.012DOI Listing
April 2018

An immune clock of human pregnancy.

Sci Immunol 2017 Sep;2(15)

Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA 94121, USA.

The maintenance of pregnancy relies on finely tuned immune adaptations. We demonstrate that these adaptations are precisely timed, reflecting an immune clock of pregnancy in women delivering at term. Using mass cytometry, the abundance and functional responses of all major immune cell subsets were quantified in serial blood samples collected throughout pregnancy. Cell signaling-based Elastic Net, a regularized regression method adapted from the elastic net algorithm, was developed to infer and prospectively validate a predictive model of interrelated immune events that accurately captures the chronology of pregnancy. Model components highlighted existing knowledge and revealed previously unreported biology, including a critical role for the interleukin-2-dependent STAT5ab signaling pathway in modulating T cell function during pregnancy. These findings unravel the precise timing of immunological events occurring during a term pregnancy and provide the analytical framework to identify immunological deviations implicated in pregnancy-related pathologies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciimmunol.aan2946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5701281PMC
September 2017

Novel nonsense gain-of-function mutations associated with a combined immunodeficiency phenotype.

Blood 2017 09 4;130(13):1553-1564. Epub 2017 Aug 4.

Immunology Service, Department of Laboratory Medicine, Clinical Center, National Institutes of Health (NIH), Bethesda, MD.

NF-κB signaling through its -dependent canonical and -dependent noncanonical pathways plays distinctive roles in a diverse range of immune processes. Recently, mutations in these 2 genes have been associated with common variable immunodeficiency (CVID). While studying patients with genetically uncharacterized primary immunodeficiencies, we detected 2 novel nonsense gain-of-function (GOF) mutations (E418X and R635X) in 3 patients from 2 families, and a novel missense change (S866R) in another patient. Their immunophenotype was assessed by flow cytometry and protein expression; activation of canonical and noncanonical pathways was examined in peripheral blood mononuclear cells and transfected HEK293T cells through immunoblotting, immunohistochemistry, luciferase activity, real-time polymerase chain reaction, and multiplex assays. The S866R change disrupted a C-terminal NF-κΒ2 critical site affecting protein phosphorylation and nuclear translocation, resulting in CVID with adrenocorticotropic hormone deficiency, growth hormone deficiency, and mild ectodermal dysplasia as previously described. In contrast, the nonsense mutations E418X and R635X observed in 3 patients led to constitutive nuclear localization and activation of both canonical and noncanonical NF-κΒ pathways, resulting in a combined immunodeficiency (CID) without endocrine or ectodermal manifestations. These changes were also found in 2 asymptomatic relatives. Thus, these novel GOF mutations produce a nonfully penetrant CID phenotype through a different pathophysiologic mechanism than previously described for mutations in .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood-2017-05-782177DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5620416PMC
September 2017

Angiotensin-Converting Enzyme Inhibition Early After Heart Transplantation.

J Am Coll Cardiol 2017 Jun;69(23):2832-2841

Stanford Cardiovascular Institute and Division of Cardiovascular Medicine, Stanford, California.

Background: Cardiac allograft vasculopathy (CAV) remains a leading cause of mortality after heart transplantation (HT). Angiotensin-converting enzyme inhibitors (ACEIs) may retard the development of CAV but have not been well studied after HT.

Objectives: This study tested the safety and efficacy of the ACEI ramipril on the development of CAV early after HT.

Methods: In this prospective, multicenter, randomized, double-blind, placebo-controlled trial, 96 HT recipients were randomized to undergo ramipril or placebo therapy. They underwent coronary angiography, endothelial function testing; measurements of fractional flow reserve (FFR) and coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR); and intravascular ultrasonography (IVUS) of the left anterior descending coronary artery, within 8 weeks of HT. At 1 year, the invasive assessment was repeated. Circulating endothelial progenitor cells (EPCs) were quantified at baseline and 1 year.

Results: Plaque volumes at 1 year were similar between the ramipril and placebo groups (162.1 ± 70.5 mm vs. 177.3 ± 94.3 mm, respectively; p = 0.73). Patients receiving ramipril had improvement in microvascular function as shown by a significant decrease in IMR (21.4 ± 14.7 to 14.4 ± 6.3; p = 0.001) and increase in CFR (3.8 ± 1.7 to 4.8 ± 1.5; p = 0.017), from baseline to 1 year. This did not occur with IMR (17.4 ± 8.4 to 21.5 ± 20.0; p = 0.72) or CFR (4.1 ± 1.8 to 4.1 ± 2.2; p = 0.60) in the placebo-treated patients. EPCs decreased significantly at 1 year in the placebo group but not in the ramipril group.

Conclusions: Ramipril does not slow development of epicardial plaque volume but does stabilize levels of endothelial progenitor cells and improve microvascular function, which have been associated with improved long-term survival after HT. (Angiotensin Converting Enzyme [ACE] Inhibition and Cardiac Allograft Vasculopathy; NCT01078363).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jacc.2017.03.598DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5546225PMC
June 2017

A Case Report of Hypoglycemia and Hypogammaglobulinemia: DAVID Syndrome in a Patient With a Novel NFKB2 Mutation.

J Clin Endocrinol Metab 2017 07;102(7):2127-2130

Division of Allergy, Immunology & Rheumatology, Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305.

Context: Deficient anterior pituitary with variable immune deficiency (DAVID) syndrome is a rare disorder in which children present with symptomatic adrenocorticotropic hormone (ACTH) deficiency preceded by hypogammaglobulinemia from B-cell dysfunction with recurrent infections, called common variable immunodeficiency (CVID). Subsequent whole exome sequencing studies have revealed germline heterozygous C-terminal mutations of NFKB2 as a cause of DAVID syndrome or of CVID without clinical hypopituitarism. However, to the best of our knowledge there have been no cases in which the endocrinopathy has presented in the absence of a prior clinical history of CVID.

Case Description: A previously healthy 7-year-old boy with no history of clinical immunodeficiency presented with profound hypoglycemia and seizures. He was found to have secondary adrenal insufficiency and was started on glucocorticoid replacement. An evaluation for autoimmune disease, including for antipituitary antibodies, was negative. Evaluation unexpectedly revealed hypogammaglobulinemia [decreased immunoglobulin G (IgG), IgM, and IgA]. He had moderately reduced serotype-specific IgG responses after pneumococcal polysaccharide vaccine. Subsequently, he was found to have growth hormone deficiency. Six years after initial presentation, whole exome sequencing revealed a de novo heterozygous NFKB2 missense mutation c.2596A>C (p.Ser866Arg) in the C-terminal region predicted to abrogate the processing of the p100 NFKB2 protein to its active p52 form.

Conclusions: Isolated early-onset ACTH deficiency is rare, and C-terminal region NFKB2 mutations should be considered as an etiology even in the absence of a clinical history of CVID. Early immunologic evaluation is indicated in the diagnosis and management of isolated ACTH deficiency.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/jc.2017-00341DOI Listing
July 2017

Enhancing protection for vulnerable waters.

Nat Geosci 2017 ;10(11):809-815

Joseph W. Jones Ecological Research Center, Newton, Georgia 39870, USA.

Governments worldwide do not adequately protect their limited freshwater systems and therefore place freshwater functions and attendant ecosystem services at risk. The best available scientific evidence compels enhanced protections for freshwater systems, especially for impermanent streams and wetlands outside of floodplains that are particularly vulnerable to alteration or destruction. New approaches to freshwater sustainability - implemented through scientifically informed adaptive management - are required to protect freshwater systems through periods of changing societal needs. One such approach introduced in the US in 2015 is the Clean Water Rule, which clarified the jurisdictional scope for federally protected waters. However, within hours of its implementation litigants convinced the US Court of Appeals for the Sixth Circuit to stay the rule, and the subsequently elected administration has now placed it under review for potential revision or rescission. Regardless of its outcome at the federal level, policy and management discussions initiated by the propagation of this rare rulemaking event have potential far-reaching implications at all levels of government across the US and worldwide. At this timely juncture, we provide a scientific rationale and three policy options for all levels of government to meaningfully enhance protection of these vulnerable waters. A fourth option, a 'do-nothing' approach, is wholly inconsistent with the well-established scientific evidence of the importance of these vulnerable waters.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ngeo3041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6071434PMC
January 2017

Mapping the Fetomaternal Peripheral Immune System at Term Pregnancy.

J Immunol 2016 12 28;197(11):4482-4492. Epub 2016 Oct 28.

Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA 94305;

Preterm labor and infections are the leading causes of neonatal deaths worldwide. During pregnancy, immunological cross talk between the mother and her fetus is critical for the maintenance of pregnancy and the delivery of an immunocompetent neonate. A precise understanding of healthy fetomaternal immunity is the important first step to identifying dysregulated immune mechanisms driving adverse maternal or neonatal outcomes. This study combined single-cell mass cytometry of paired peripheral and umbilical cord blood samples from mothers and their neonates with a graphical approach developed for the visualization of high-dimensional data to provide a high-resolution reference map of the cellular composition and functional organization of the healthy fetal and maternal immune systems at birth. The approach enabled mapping of known phenotypical and functional characteristics of fetal immunity (including the functional hyperresponsiveness of CD4 and CD8 T cells and the global blunting of innate immune responses). It also allowed discovery of new properties that distinguish the fetal and maternal immune systems. For example, examination of paired samples revealed differences in endogenous signaling tone that are unique to a mother and her offspring, including increased ERK1/2, MAPK-activated protein kinase 2, rpS6, and CREB phosphorylation in fetal TbetCD4 T cells, CD8 T cells, B cells, and CD56CD16 NK cells and decreased ERK1/2, MAPK-activated protein kinase 2, and STAT1 phosphorylation in fetal intermediate and nonclassical monocytes. This highly interactive functional map of healthy fetomaternal immunity builds the core reference for a growing data repository that will allow inferring deviations from normal associated with adverse maternal and neonatal outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1601195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5125527PMC
December 2016

Treatment of CGD-associated Colitis with the IL-23 Blocker Ustekinumab.

J Clin Immunol 2016 10 27;36(7):619-20. Epub 2016 Jul 27.

Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, Stanford University, 300 Pasteur Drive, Grant Building Room H307A, Stanford, CA, 94305, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10875-016-0318-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5018915PMC
October 2016

A cationic liposome-DNA complexes adjuvant (JVRS-100) enhances the immunogenicity and cross-protective efficacy of pre-pandemic influenza A (H5N1) vaccine in ferrets.

Virology 2016 May 21;492:197-203. Epub 2016 Mar 21.

Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA, USA. Electronic address:

Influenza A (H5N1) viruses continue to pose a public health threat. As inactivated H5N1 vaccines are poorly immunogenic, adjuvants are needed to improve the immunogenicity of H5N1 vaccine in humans. Here, we investigated the immunogenicity and cross-protective efficacy in ferrets of a clade 2.2-derived vaccine with addition of JVRS-100, an adjuvant consisting of cationic liposome-DNA complexes (CLDC). After the first vaccination, significantly higher levels of hemagglutination-inhibition (HAI) and neutralizing antibody titers were detected in ferrets immunized with adjuvanted vaccine compared to unadjuvanted vaccine. Following a second dose of adjuvanted vaccine, HAI antibody titers of ≥ 40 were detected against viruses from multiple H5N1 clades. HAI antibodies against newly isolated H5N2 and H5N8 viruses were also augmented by JVRS-100. Ferrets were challenged with a heterologous H5N1 virus. All ferrets that received two doses of adjuvanted vaccine exhibited mild illness, significantly reduced nasal wash virus titers and protection from lethal challenge. In contrast, ferrets that received unadjuvanted vaccine showed greater weight loss, high viral titers and 3 of 6 animals succumbed to the lethal challenge. Our results indicate that the addition of JVRS-100 to H5N1 vaccine enhanced immunogenicity and cross-protection against lethal H5N1 virus disease in ferrets. JVRS-100 warrants further investigation as a potential adjuvant for influenza vaccines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.virol.2016.02.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5796654PMC
May 2016

Longitudinal Kinetics of Cytomegalovirus-Specific T-Cell Immunity and Viral Replication in Infants With Congenital Cytomegalovirus Infection.

J Pediatric Infect Dis Soc 2016 Mar 11;5(1):14-20. Epub 2014 Sep 11.

Department of Pediatrics.

Background: Congenital cytomegalovirus (CMV) is reported to affect up to 1% of all live births in the United States. T-cell immunity may be important for controlling CMV replication in congenital CMV-infected infants. We describe the natural history of CMV-specific T-cell evolution and CMV replication in infants with congenital CMV infection.

Methods: Cytomegalovirus viral load, CMV urine culture, and CMV-specific CD4 and CD8 T-cell responses were assessed in a prospective longitudinal cohort of 51 infants with congenital CMV infection who were observed from birth to 3 years of age.

Results: We found a kinetic pattern of decreasing urinary CMV replication and increasing CMV-specific CD4 and CD8 T-cell responses during the first 3 years of life. We also found higher CMV-specific CD8 T-cell responses were associated with subsequent reduction of urine CMV viral load.

Conclusion: For infants with congenital CMV infection, our data suggest an age-related maturation of both CMV-specific CD4 and CD8 T-cell immunity that is associated with an age-related decline in urinary CMV replication.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jpids/piu089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4765489PMC
March 2016

Lack of IL7Rα expression in T cells is a hallmark of T-cell immunodeficiency in Schimke immuno-osseous dysplasia (SIOD).

Clin Immunol 2015 Dec 21;161(2):355-65. Epub 2015 Oct 21.

Department of Medical Genetics and Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada. Electronic address:

Schimke immuno-osseous dysplasia (SIOD) is an autosomal recessive, fatal childhood disorder associated with skeletal dysplasia, renal dysfunction, and T-cell immunodeficiency. This disease is linked to biallelic loss-of-function mutations of the SMARCAL1 gene. Although recurrent infection, due to T-cell deficiency, is a leading cause of morbidity and mortality, the etiology of the T-cell immunodeficiency is unclear. Here, we demonstrate that the T cells of SIOD patients have undetectable levels of protein and mRNA for the IL-7 receptor alpha chain (IL7Rα) and are unresponsive to stimulation with IL-7, indicating a loss of functional receptor. No pathogenic mutations were detected in the exons of IL7R in these patients; however, CpG sites in the IL7R promoter were hypermethylated in SIOD T cells. We propose therefore that the lack of IL7Rα expression, associated with hypermethylation of the IL7R promoter, in T cells and possibly their earlier progenitors, restricts T-cell development in SIOD patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clim.2015.10.005DOI Listing
December 2015

Heightened risk of preterm birth and growth restriction after a first-born son.

Ann Epidemiol 2015 Oct 16;25(10):743-7.e1. Epub 2015 Jul 16.

Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA.

Purpose: In Scandinavia, delivery of a first-born son elevates the risk of preterm delivery and intrauterine growth restriction of the next-born infant. External validity of these results remains unclear. We test this hypothesis for preterm delivery and growth restriction using the linked California birth cohort file. We examined the hypothesis separately by race and/or ethnicity.

Methods: We retrieved data on 2,852,976 births to 1,426,488 mothers with at least two live births. Our within-mother tests applied Cox proportional hazards (preterm delivery, defined as less than 37 weeks gestation) and linear regression models (birth weight for gestational age percentiles).

Results: For non-Hispanic whites, Hispanics, Asians, and American Indian and/or Alaska Natives, analyses indicate heightened risk of preterm delivery and growth restriction after a first-born male. The race-specific hazard ratios for preterm delivery range from 1.07 to 1.18. Regression coefficients for birth weight for gestational age percentile range from -0.73 to -1.49. The 95% confidence intervals for all these estimates do not contain the null. By contrast, we could not reject the null for non-Hispanic black mothers.

Conclusions: Whereas California findings generally support those from Scandinavia, the null results among non-Hispanic black mothers suggest that we do not detect adverse outcomes after a first-born male in all racial and/or ethnic groups.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.annepidem.2015.07.002DOI Listing
October 2015

Implementing Mass Cytometry at the Bedside to Study the Immunological Basis of Human Diseases: Distinctive Immune Features in Patients with a History of Term or Preterm Birth.

Cytometry A 2015 Sep 17;87(9):817-29. Epub 2015 Jul 17.

Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University, School of Medicine, Stanford, California, 94305.

Single-cell technologies have immense potential to shed light on molecular and biological processes that drive human diseases. Mass cytometry (or Cytometry by Time Of Flight mass spectrometry, CyTOF) has already been employed in clinical studies to comprehensively survey patients' circulating immune system. As interest in the "bedside" application of mass cytometry is growing, the delineation of relevant methodological issues is called for. This report uses a newly generated dataset to discuss important methodological considerations when mass cytometry is implemented in a clinical study. Specifically, the use of whole blood samples versus peripheral blood mononuclear cells (PBMCs), design of mass-tagged antibody panels, technical and analytical implications of sample barcoding, and application of traditional and unsupervised approaches to analyze high-dimensional mass cytometry datasets are discussed. A mass cytometry assay was implemented in a cross-sectional study of 19 women with a history of term or preterm birth to determine whether immune traits in peripheral blood differentiate the two groups in the absence of pregnancy. Twenty-seven phenotypic and 11 intracellular markers were simultaneously analyzed in whole blood samples stimulated with lipopolysaccharide (LPS at 0, 0.1, 1, 10, and 100 ng mL(-1)) to examine dose-dependent signaling responses within the toll-like receptor 4 (TLR4) pathway. Complementary analyses, grounded in traditional or unsupervised gating strategies of immune cell subsets, indicated that the prpS6 and pMAPKAPK2 responses in classical monocytes are accentuated in women with a history of preterm birth (FDR<1%). The results suggest that women predisposed to preterm birth may be prone to mount an exacerbated TLR4 response during the course of pregnancy. This important hypothesis-generating finding points to the power of single-cell mass cytometry to detect biologically important differences in a relatively small patient cohort.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cyto.a.22720DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4758855PMC
September 2015

Single-cell systems-level analysis of human Toll-like receptor activation defines a chemokine signature in patients with systemic lupus erythematosus.

J Allergy Clin Immunol 2015 Nov 30;136(5):1326-36. Epub 2015 May 30.

Department of Microbiology and Immunology, Stanford University, Stanford, Calif; Institute for Immunity, Transplantation and Infection, Stanford University, Stanford, Calif; Howard Hughes Medical Institute, Stanford University, Stanford, Calif. Electronic address:

Background: Activation of Toll-like receptors (TLRs) induces inflammatory responses involved in immunity to pathogens and autoimmune pathogenesis, such as in patients with systemic lupus erythematosus (SLE). Although TLRs are differentially expressed across the immune system, a comprehensive analysis of how multiple immune cell subsets respond in a system-wide manner has not been described.

Objective: We sought to characterize TLR activation across multiple immune cell subsets and subjects, with the goal of establishing a reference framework against which to compare pathologic processes.

Methods: Peripheral whole-blood samples were stimulated with TLR ligands and analyzed by means of mass cytometry simultaneously for surface marker expression, activation states of intracellular signaling proteins, and cytokine production. We developed a novel data visualization tool to provide an integrated view of TLR signaling networks with single-cell resolution. We studied 17 healthy volunteer donors and 8 patients with newly diagnosed and untreated SLE.

Results: Our data revealed the diversity of TLR-induced responses within cell types, with TLR ligand specificity. Subsets of natural killer cells and T cells selectively induced nuclear factor κ light chain enhancer of activated B cells in response to TLR2 ligands. CD14(hi) monocytes exhibited the most polyfunctional cytokine expression patterns, with more than 80 distinct cytokine combinations. Monocytic TLR-induced cytokine patterns were shared among a group of healthy donors, with minimal intraindividual and interindividual variability. Furthermore, autoimmune disease altered baseline cytokine production; newly diagnosed untreated SLE patients shared a distinct monocytic chemokine signature, despite clinical heterogeneity.

Conclusion: Mass cytometry defined a systems-level reference framework for human TLR activation, which can be applied to study perturbations in patients with inflammatory diseases, such as SLE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2015.04.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4640970PMC
November 2015

Heme oxygenase and the immune system in normal and pathological pregnancies.

Front Pharmacol 2015 24;6:84. Epub 2015 Apr 24.

Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine , Stanford, CA, USA.

Normal pregnancy is an immunotolerant state. Many factors, including environmental, socioeconomic, genetic, and immunologic changes by infection and/or other causes of inflammation, may contribute to inter-individual differences resulting in a normal or pathologic pregnancy. In particular, imbalances in the immune system can cause many pregnancy-related diseases, such as infertility, abortions, pre-eclampsia, and preterm labor, which result in maternal/fetal death, prematurity, or small-for-gestational age newborns. New findings imply that myeloid regulatory cells and regulatory T cells (Tregs) may mediate immunotolerance during normal pregnancy. Effector T cells (Teffs) have, in contrast, been implicated to cause adverse pregnancy outcomes. Furthermore, feto-maternal tolerance affects the developing fetus. It has been shown that the Treg/Teff balance affects litter size and adoptive transfer of pregnancy-induced Tregs can prevent fetal rejection in the mouse. Heme oxygenase-1 (HO-1) has a protective role in many conditions through its anti-inflammatory, anti-apoptotic, antioxidative, and anti-proliferative actions. HO-1 is highly expressed in the placenta and plays a role in angiogenesis and placental vascular development and in regulating vascular tone in pregnancy. In addition, HO-1 is a major regulator of immune homeostasis by mediating crosstalk between innate and adaptive immune systems. Moreover, HO-1 can inhibit inflammation-induced phenotypic maturation of immune effector cells and pro-inflammatory cytokine secretion and promote anti-inflammatory cytokine production. HO-1 may also be associated with T-cell activation and can limit immune-based tissue injury by promoting Treg suppression of effector responses. Thus, HO-1 and its byproducts may protect against pregnancy complications by its immunomodulatory effects, and the regulation of HO-1 or its downstream effects has the potential to prevent or treat pregnancy complications and prematurity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2015.00084DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408852PMC
May 2015

Bayesian immunological model development from the literature: example investigation of recent thymic emigrants.

J Immunol Methods 2014 Dec 29;414:32-50. Epub 2014 Aug 29.

Department of Pediatrics, Stanford Immunology Program, and the Institute for Immunity, Transplantation, and Infectious Disease, Stanford University School of Medicine, CCSR Building, Room 3215A, 269 Campus Drive, Stanford, CA 94305-5366, USA. Electronic address:

Bayesian estimation techniques offer a systematic and quantitative approach for synthesizing data drawn from the literature to model immunological systems. As detailed here, the practitioner begins with a theoretical model and then sequentially draws information from source data sets and/or published findings to inform estimation of model parameters. Options are available to weigh these various sources of information differentially per objective measures of their corresponding scientific strengths. This approach is illustrated in depth through a carefully worked example for a model of decline in T-cell receptor excision circle content of peripheral T cells during development and aging. Estimates from this model indicate that 21 years of age is plausible for the developmental timing of mean age of onset of decline in T-cell receptor excision circle content of peripheral T cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jim.2014.08.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4259859PMC
December 2014

Somatic reversion in dedicator of cytokinesis 8 immunodeficiency modulates disease phenotype.

J Allergy Clin Immunol 2014 Jun 3;133(6):1667-75. Epub 2014 May 3.

Laboratory of Host Defenses, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), Bethesda, Md. Electronic address:

Background: Autosomal recessive loss-of-function mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency characterized by atopy, recurrent infections, and cancer susceptibility. A genotype-phenotype explanation for the variable disease expression is lacking.

Objective: We investigated whether reversions contributed to the variable disease expression.

Methods: Patients followed at the National Institutes of Health's Clinical Center were studied. We performed detailed genetic analyses and intracellular flow cytometry to detect DOCK8 protein expression within lymphocyte subsets.

Results: We identified 17 of 34 DOCK8-deficient patients who had germline mutations with variable degrees of reversion caused by somatic repair. Somatic repair of the DOCK8 mutations resulted from second-site mutation, original-site mutation, gene conversion, and intragenic crossover. Higher degrees of reversion were associated with recombination-mediated repair. DOCK8 expression was restored primarily within antigen-experienced T cells or natural killer cells but less so in naive T or B cells. Several patients exhibited multiple different repair events. Patients who had reversions were older and had less severe allergic disease, although infection susceptibility persisted. No patients were cured without hematopoietic cell transplantation.

Conclusions: In patients with DOCK8 deficiency, only certain combinations of germline mutations supported secondary somatic repair. Those patients had an ameliorated disease course with longer survival but still had fatal complications or required hematopoietic cell transplantation. These observations support the concept that some DOCK8-immunodeficient patients have mutable mosaic genomes that can modulate disease phenotype over time.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2014.03.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4132167PMC
June 2014

ICOS regulates the generation and function of human CD4+ Treg in a CTLA-4 dependent manner.

PLoS One 2013 2;8(12):e82203. Epub 2013 Dec 2.

Department of Pediatrics and Adolescent Medicine, LKS Faculty of Medicine, the University of Hong Kong, Hong Kong SAR, PR China.

Inducible co-stimulator (ICOS) is a member of CD28/Cytotoxic T-lymphocyte Antigen-4 (CTLA-4) family and broadly expressed in activated CD4(+) T cells and induced regulatory CD4(+) T cells (CD4(+) iTreg). ICOS-related signal pathway could be activated by the interaction between ICOS and its ligand (ICOSL). In our previous work, we established a cost-effective system to generate a novel human allo-antigen specific CD4(hi) Treg by co-culturing their naïve precursors with allogeneic CD40-activated B cells in vitro. Here we investigate the role of ICOS in the generation and function of CD4(hi) Treg by interrupting ICOS-ICOSL interaction with ICOS-Ig. It is found that blockade of ICOS-ICOSL interaction impairs the induction and expansion of CD4(hi) Treg induced by allogeneic CD40-activated B cells. More importantly, CD4(hi) Treg induced with the addition of ICOS-Ig exhibits decreased suppressive capacity on alloantigen-specific responses. Dysfunction of CD4(hi) Treg induced with ICOS-Ig is accompanied with its decreased exocytosis and surface CTLA-4 expression. Through inhibiting endocytosis with E64 and pepstatin A, surface CTLA-4 expression and suppressive functions of induced CD4(hi) Treg could be partly reversed. Conclusively, our results demonstrate the beneficial role of ICOS-ICOSL signal pathway in the generation and function of CD4(hi) Treg and uncover a novel relationship between ICOS and CTLA-4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082203PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3846688PMC
February 2015

Defective sphingosine 1-phosphate receptor 1 (S1P1) phosphorylation exacerbates TH17-mediated autoimmune neuroinflammation.

Nat Immunol 2013 Nov 29;14(11):1166-72. Epub 2013 Sep 29.

1] Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA. [2] Graduate Program in Immunology, Division of Medical Sciences, Harvard Medical School, Boston, Massachusetts, USA. [3].

Sphingosine 1-phosphate (S1P) signaling regulates lymphocyte egress from lymphoid organs into systemic circulation. The sphingosine phosphate receptor 1 (S1P1) agonist FTY-720 (Gilenya) arrests immune trafficking and prevents multiple sclerosis (MS) relapses. However, alternative mechanisms of S1P-S1P1 signaling have been reported. Phosphoproteomic analysis of MS brain lesions revealed S1P1 phosphorylation on S351, a residue crucial for receptor internalization. Mutant mice harboring an S1pr1 gene encoding phosphorylation-deficient receptors (S1P1(S5A)) developed severe experimental autoimmune encephalomyelitis (EAE) due to autoimmunity mediated by interleukin 17 (IL-17)-producing helper T cells (TH17 cells) in the peripheral immune and nervous system. S1P1 directly activated the Jak-STAT3 signal-transduction pathway via IL-6. Impaired S1P1 phosphorylation enhances TH17 polarization and exacerbates autoimmune neuroinflammation. These mechanisms may be pathogenic in MS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/ni.2730DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4014310PMC
November 2013

Newborn screening for severe combined immunodeficiency and T-cell lymphopenia in California: results of the first 2 years.

J Allergy Clin Immunol 2013 Jul;132(1):140-50

Department of Pediatrics, University of California San Francisco and UCSF Benioff Children's Hospital, San Francisco, CA 94143-0519, USA.

Background: Assay of T-cell receptor excision circles (TRECs) in dried blood spots obtained at birth permits population-based newborn screening (NBS) for severe combined immunodeficiency (SCID).

Objective: We sought to report the first 2 years of TREC NBS in California.

Methods: Since August 2010, California has conducted SCID NBS. A high-throughput TREC quantitative PCR assay with DNA isolated from routine dried blood spots was developed. Samples with initial low TREC numbers had repeat DNA isolation with quantitative PCR for TRECs and a genomic control, and immunophenotyping was performed within the screening program for infants with incomplete or abnormal results. Outcomes were tracked.

Results: Of 993,724 infants screened, 50 (1/19,900 [0.005%]) had significant T-cell lymphopenia. Fifteen (1/66,250) required hematopoietic cell or thymus transplantation or gene therapy; these infants had typical SCID (n = 11), leaky SCID or Omenn syndrome (n = 3), or complete DiGeorge syndrome (n = 1). Survival to date in this group is 93%. Other T-cell lymphopenic infants had variant SCID or combined immunodeficiency (n = 6), genetic syndromes associated with T-cell impairment (n = 12), secondary T-cell lymphopenia (n = 9), or preterm birth (n = 8). All T-cell lymphopenic infants avoided live vaccines and received appropriate interventions to prevent infections. TREC test specificity was excellent: only 0.08% of infants required a second test, and 0.016% required lymphocyte phenotyping by using flow cytometry.

Conclusions: TREC NBS in California has achieved early diagnosis of SCID and other conditions with T-cell lymphopenia, facilitating management and optimizing outcomes. Furthermore, NBS has revealed the incidence, causes, and follow-up of T-cell lymphopenia in a large diverse population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2013.04.024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3759317PMC
July 2013

Human neonatal naive CD4+ T cells have enhanced activation-dependent signaling regulated by the microRNA miR-181a.

J Immunol 2013 Mar 13;190(6):2682-91. Epub 2013 Feb 13.

Department of Pediatrics, Program in Immunology, Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Stanford, CA 94305, USA.

Compared with older children and adults, human neonates have reduced and delayed CD4(+) T cell immunity to certain pathogens, but the mechanisms for these developmental differences in immune function remain poorly understood. We investigated the hypothesis that impaired human neonatal CD4(+) T cell immunity was due to reduced signaling by naive CD4(+) T cells following engagement of the αβ-TCR/CD3 complex and CD28. Surprisingly, calcium flux following engagement of CD3 was significantly higher in neonatal naive CD4(+) T cells from umbilical cord blood (CB) compared with naive CD4(+) T cells from adult peripheral blood. Enhanced calcium flux was also observed in adult CD4(+) recent thymic emigrants. Neonatal naive CD4(+) T cells also had higher activation-induced Erk phosphorylation. The microRNA miR-181a, which enhances activation-induced calcium flux in murine thymocytes, was expressed at significantly higher levels in CB naive CD4(+) T cells compared with adult cells. Overexpression of miR-181a in adult naive CD4(+) T cells increased activation-induced calcium flux, implying that the increased miR-181a levels of CB naive CD4(+) T cells contributed to their enhanced signaling. In contrast, AP-1-dependent transcription, which is downstream of Erk and required for full T cell activation, was decreased in CB naive CD4(+) T cells compared with adult cells. Thus, CB naive CD4(+) T cells have enhanced activation-dependent calcium flux, indicative of the retention of a thymocyte-like phenotype. Enhanced calcium signaling and Erk phosphorylation are decoupled from downstream AP-1-dependent transcription, which is reduced and likely contributes to limitations of human fetal and neonatal CD4(+) T cell immunity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1202534DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3952015PMC
March 2013